Sample records for eye evaluation driving

  1. Real-time eye tracking for the assessment of driver fatigue.

    PubMed

    Xu, Junli; Min, Jianliang; Hu, Jianfeng

    2018-04-01

    Eye-tracking is an important approach to collect evidence regarding some participants' driving fatigue. In this contribution, the authors present a non-intrusive system for evaluating driver fatigue by tracking eye movement behaviours. A real-time eye-tracker was used to monitor participants' eye state for collecting eye-movement data. These data are useful to get insights into assessing participants' fatigue state during monotonous driving. Ten healthy subjects performed continuous simulated driving for 1-2 h with eye state monitoring on a driving simulator in this study, and these measured features of the fixation time and the pupil area were recorded via using eye movement tracking device. For achieving a good cost-performance ratio and fast computation time, the fuzzy K -nearest neighbour was employed to evaluate and analyse the influence of different participants on the variations in the fixation duration and pupil area of drivers. The findings of this study indicated that there are significant differences in domain value distribution of the pupil area under the condition with normal and fatigue driving state. Result also suggests that the recognition accuracy by jackknife validation reaches to about 89% in average, implying that show a significant potential of real-time applicability of the proposed approach and is capable of detecting driver fatigue.

  2. Real-time eye tracking for the assessment of driver fatigue

    PubMed Central

    Xu, Junli; Min, Jianliang

    2018-01-01

    Eye-tracking is an important approach to collect evidence regarding some participants’ driving fatigue. In this contribution, the authors present a non-intrusive system for evaluating driver fatigue by tracking eye movement behaviours. A real-time eye-tracker was used to monitor participants’ eye state for collecting eye-movement data. These data are useful to get insights into assessing participants’ fatigue state during monotonous driving. Ten healthy subjects performed continuous simulated driving for 1–2 h with eye state monitoring on a driving simulator in this study, and these measured features of the fixation time and the pupil area were recorded via using eye movement tracking device. For achieving a good cost-performance ratio and fast computation time, the fuzzy K-nearest neighbour was employed to evaluate and analyse the influence of different participants on the variations in the fixation duration and pupil area of drivers. The findings of this study indicated that there are significant differences in domain value distribution of the pupil area under the condition with normal and fatigue driving state. Result also suggests that the recognition accuracy by jackknife validation reaches to about 89% in average, implying that show a significant potential of real-time applicability of the proposed approach and is capable of detecting driver fatigue. PMID:29750113

  3. Evaluating and Enhancing Driving Ability Among Teens with Autism Spectrum Disorder (ASD)

    DTIC Science & Technology

    2014-10-01

    impact. 15. SUBJECT TERMS Autism, Driving Safety , Driving Simulation, Automated Feedback, Eye Tracking 16. SECURITY CLASSIFICATION OF: 17...driving training (RT) required by the DMV, VRDS training + RT (VRDS-T) would lead to greater improvement in driving safety and less driving anxiety, 2...the Idea Development award we learned that VRDS-T can significantly improve the driving safety of novice drivers with ASD, and this is not enhanced by

  4. Hemianopic and Quadrantanopic Field Loss, Eye and Head Movements, and Driving

    PubMed Central

    McGwin, Gerald; Elgin, Jennifer; Vaphiades, Michael S.; Braswell, Ronald A.; DeCarlo, Dawn K.; Kline, Lanning B.; Owsley, Cynthia

    2011-01-01

    Purpose. To compare eye and head movements, lane keeping, and vehicle control of drivers with hemianopic and quadrantanopic field defects with controls, and to identify differences in these parameters between hemianopic and quadrantanopic drivers rated safe to drive by a clinical driving rehabilitation specialist compared with those rated as unsafe. Methods. Eye and head movements and lane keeping were rated in 22 persons with homonymous hemianopic defects and 8 with quadrantanopic defects (mean age, 53 years) who were ≥6 months post-injury and 30 persons with normal fields (mean age, 53 years). All were licensed to drive and were current drivers or aimed to resume driving. Participants drove a 6.3-mile route along non-interstate city roads under in-traffic conditions. Vehicle control was assessed objectively by vehicle instrumentation for speed, braking, acceleration, and cornering. Results. As a group, drivers with hemianopic or quadrantanopic defects drove slower, exhibited less excessive cornering or acceleration, and executed more shoulder movements than the controls. Those drivers with hemianopic or quadrantanopic defects rated as safe also made more head movements into their blind field, received superior ratings regarding eye movement extent and lane position stability, and exhibited less sudden braking and drove faster than those rated unsafe. Conclusions. Persons with hemianopic and quadrantanopic defects rated as safe to drive compensated by making more head movements into their blind field, combined with more stable lane keeping and less sudden braking. Future research should evaluate whether these characteristics could be trained in rehabilitation programs aimed at improving driving safety in this population. PMID:21367969

  5. Consequences of cognitive impairments following traumatic brain injury: Pilot study on visual exploration while driving.

    PubMed

    Milleville-Pennel, Isabelle; Pothier, Johanna; Hoc, Jean-Michel; Mathé, Jean-François

    2010-01-01

    The aim was to assess the visual exploration of a person suffering from traumatic brain injury (TBI). It was hypothesized that visual exploration could be modified as a result of attentional or executive function deficits that are often observed following brain injury. This study compared an analysis of eyes movements while driving with data from neuropsychological tests. Five participants suffering from TBI and six control participants took part in this study. All had good driving experience. They were invited to drive on a fixed-base driving simulator. Eye fixations were recorded using an eye tracker. Neuropsychological tests were used to assess attention, working memory, rapidity of information processing and executive functions. Participants with TBI showed a reduction in the variety of the visual zones explored and a reduction of the distance of exploration. Moreover, neuropsychological evaluation indicates that there were difficulties in terms of divided attention, anticipation and planning. There is a complementarity of the information obtained. Tests give information about cognitive deficiencies but not about their translation into a dynamic situation. Conversely, visual exploration provides information about the dynamic with which information is picked up in the environment but not about the cognitive processes involved.

  6. Research on safety evaluation model for in-vehicle secondary task driving.

    PubMed

    Jin, Lisheng; Xian, Huacai; Niu, Qingning; Bie, Jing

    2015-08-01

    This paper presents a new method for evaluating in-vehicle secondary task driving safety. There are five in-vehicle distracter tasks: tuning the radio to a local station, touching the touch-screen telephone menu to a certain song, talking with laboratory assistant, answering a telephone via Bluetooth headset, and finding the navigation system from Ipad4 computer. Forty young drivers completed the driving experiment on a driving simulator. Measures of fixations, saccades, and blinks are collected and analyzed. Based on the measures of driver eye movements which have significant difference between the baseline and secondary task driving conditions, the evaluation index system is built. The Analytic Network Process (ANP) theory is applied for determining the importance weight of the evaluation index in a fuzzy environment. On the basis of the importance weight of the evaluation index, Fuzzy Comprehensive Evaluation (FCE) method is utilized to evaluate the secondary task driving safety. Results show that driving with secondary tasks greatly distracts the driver's attention from road and the evaluation model built in this study could estimate driving safety effectively under different driving conditions. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  7. Assessment of the vision-specific quality of life using clustered visual field in glaucoma patients.

    PubMed

    Sawada, Hideko; Yoshino, Takaiko; Fukuchi, Takeo; Abe, Haruki

    2014-02-01

    To investigate the significance of vision-specific quality of life (QOL) in glaucoma patients based on the location of visual field defects. We examined 336 eyes of 168 patients. The 25-item National Eye Institute Visual Function Questionnaire was used to evaluate patients' QOL. Visual field testing was performed using the Humphrey Field Analyzer; the visual field was divided into 10 clusters. We defined the eye with better mean deviation as the better eye and the fellow eye as the worse eye. A single linear regression analysis was applied to assess the significance of the relationship between QOL and the clustered visual field. The strongest correlation was observed in the lower paracentral visual field in the better eye. The lower peripheral visual field in the better eye also showed a good correlation. Correlation coefficients in the better eye were generally higher than those in the worse eye. For driving, the upper temporal visual field in the better eye was the most strongly correlated (r=0.509). For role limitation and peripheral vision, the lower peripheral visual field in the better eye had the highest correlation coefficients at 0.459 and 0.425, respectively. Overall, clusters in the lower hemifield in the better eye were more strongly correlated with QOL than those in the worse eye. In particular, the lower paracentral visual field in the better eye was correlated most strongly of all. Driving, however, strongly correlated with the upper hemifield in the better eye.

  8. Obstacle Avoidance, Visual Detection Performance, and Eye-Scanning Behavior of Glaucoma Patients in a Driving Simulator: A Preliminary Study

    PubMed Central

    Prado Vega, Rocío; van Leeuwen, Peter M.; Rendón Vélez, Elizabeth; Lemij, Hans G.; de Winter, Joost C. F.

    2013-01-01

    The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed. PMID:24146975

  9. Eye blink detection for different driver states in conditionally automated driving and manual driving using EOG and a driver camera.

    PubMed

    Schmidt, Jürgen; Laarousi, Rihab; Stolzmann, Wolfgang; Karrer-Gauß, Katja

    2018-06-01

    In this article, we examine the performance of different eye blink detection algorithms under various constraints. The goal of the present study was to evaluate the performance of an electrooculogram- and camera-based blink detection process in both manually and conditionally automated driving phases. A further comparison between alert and drowsy drivers was performed in order to evaluate the impact of drowsiness on the performance of blink detection algorithms in both driving modes. Data snippets from 14 monotonous manually driven sessions (mean 2 h 46 min) and 16 monotonous conditionally automated driven sessions (mean 2 h 45 min) were used. In addition to comparing two data-sampling frequencies for the electrooculogram measures (50 vs. 25 Hz) and four different signal-processing algorithms for the camera videos, we compared the blink detection performance of 24 reference groups. The analysis of the videos was based on very detailed definitions of eyelid closure events. The correct detection rates for the alert and manual driving phases (maximum 94%) decreased significantly in the drowsy (minus 2% or more) and conditionally automated (minus 9% or more) phases. Blinking behavior is therefore significantly impacted by drowsiness as well as by automated driving, resulting in less accurate blink detection.

  10. Driving with Binocular Visual Field Loss? A Study on a Supervised On-Road Parcours with Simultaneous Eye and Head Tracking

    PubMed Central

    Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

    2014-01-01

    Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario. PMID:24523869

  11. Retrospective analysis of the Draize test for serious eye damage/eye irritation: importance of understanding the in vivo endpoints under UN GHS/EU CLP for the development and evaluation of in vitro test methods.

    PubMed

    Adriaens, Els; Barroso, João; Eskes, Chantra; Hoffmann, Sebastian; McNamee, Pauline; Alépée, Nathalie; Bessou-Touya, Sandrine; De Smedt, Ann; De Wever, Bart; Pfannenbecker, Uwe; Tailhardat, Magalie; Zuang, Valérie

    2014-03-01

    For more than two decades, scientists have been trying to replace the regulatory in vivo Draize eye test by in vitro methods, but so far only partial replacement has been achieved. In order to better understand the reasons for this, historical in vivo rabbit data were analysed in detail and resampled with the purpose of (1) revealing which of the in vivo endpoints are most important in driving United Nations Globally Harmonized System/European Union Regulation on Classification, Labelling and Packaging (UN GHS/EU CLP) classification for serious eye damage/eye irritation and (2) evaluating the method's within-test variability for proposing acceptable and justifiable target values of sensitivity and specificity for alternative methods and their combinations in testing strategies. Among the Cat 1 chemicals evaluated, 36-65 % (depending on the database) were classified based only on persistence of effects, with the remaining being classified mostly based on severe corneal effects. Iritis was found to rarely drive the classification (<4 % of both Cat 1 and Cat 2 chemicals). The two most important endpoints driving Cat 2 classification are conjunctiva redness (75-81 %) and corneal opacity (54-75 %). The resampling analyses demonstrated an overall probability of at least 11 % that chemicals classified as Cat 1 by the Draize eye test could be equally identified as Cat 2 and of about 12 % for Cat 2 chemicals to be equally identified as No Cat. On the other hand, the over-classification error for No Cat and Cat 2 was negligible (<1 %), which strongly suggests a high over-predictive power of the Draize eye test. Moreover, our analyses of the classification drivers suggest a critical revision of the UN GHS/EU CLP decision criteria for the classification of chemicals based on Draize eye test data, in particular Cat 1 based only on persistence of conjunctiva effects or corneal opacity scores of 4. In order to successfully replace the regulatory in vivo Draize eye test, it will be important to recognise these uncertainties and to have in vitro tools to address the most important in vivo endpoints identified in this paper.

  12. A comparative evaluation of in-vehicle side view displays layouts in critical lane changing situation.

    PubMed

    Beck, Donghyun; Lee, Minho; Park, Woojin

    2017-12-01

    This study conducted a driving simulator experiment to comparatively evaluate three in-vehicle side view displays layouts for camera monitor systems (CMS) and the traditional side view mirror arrangement. The three layouts placed two electronic side view displays near the traditional mirrors positions, on the dashboard at each side of the steering wheel and on the centre fascia with the two displays joined side-by-side, respectively. Twenty-two participants performed a time- and safety-critical driving task that required rapidly gaining situation awareness through the side view displays/mirrors and making a lane change to avoid collision. The dependent variables were eye-off-the-road time, response time, and, ratings of perceived workload, preference and perceived safety. Overall, the layout placing the side view displays on the dashboard at each side of the steering wheel was found to be the best. The results indicated that reducing eye gaze travel distance and maintaining compatibility were both important for the design of CMS displays layout. Practitioner Summary: A driving simulator study was conducted to comparatively evaluate three in-vehicle side view displays layouts for camera monitor systems (CMS) and the traditional side view mirror arrangement in critical lane changing situation. Reducing eye movement and maintaining compatibility were found to be both important for the ergonomics design of CMS displays layout.

  13. Cosmetics Europe compilation of historical serious eye damage/eye irritation in vivo data analysed by drivers of classification to support the selection of chemicals for development and evaluation of alternative methods/strategies: the Draize eye test Reference Database (DRD).

    PubMed

    Barroso, João; Pfannenbecker, Uwe; Adriaens, Els; Alépée, Nathalie; Cluzel, Magalie; De Smedt, Ann; Hibatallah, Jalila; Klaric, Martina; Mewes, Karsten R; Millet, Marion; Templier, Marie; McNamee, Pauline

    2017-02-01

    A thorough understanding of which of the effects assessed in the in vivo Draize eye test are responsible for driving UN GHS/EU CLP classification is critical for an adequate selection of chemicals to be used in the development and/or evaluation of alternative methods/strategies and for properly assessing their predictive capacity and limitations. For this reason, Cosmetics Europe has compiled a database of Draize data (Draize eye test Reference Database, DRD) from external lists that were created to support past validation activities. This database contains 681 independent in vivo studies on 634 individual chemicals representing a wide range of chemical classes. A description of all the ocular effects observed in vivo, i.e. degree of severity and persistence of corneal opacity (CO), iritis, and/or conjunctiva effects, was added for each individual study in the database, and the studies were categorised according to their UN GHS/EU CLP classification and the main effect driving the classification. An evaluation of the various in vivo drivers of classification compiled in the database was performed to establish which of these are most important from a regulatory point of view. These analyses established that the most important drivers for Cat 1 Classification are (1) CO mean ≥ 3 (days 1-3) (severity) and (2) CO persistence on day 21 in the absence of severity, and those for Cat 2 classification are (3) CO mean ≥ 1 and (4) conjunctival redness mean ≥ 2. Moreover, it is shown that all classifiable effects (including persistence and CO = 4) should be present in ≥60 % of the animals to drive a classification. As a consequence, our analyses suggest the need for a critical revision of the UN GHS/EU CLP decision criteria for the Cat 1 classification of chemicals. Finally, a number of key criteria are identified that should be taken into consideration when selecting reference chemicals for the development, evaluation and/or validation of alternative methods and/or strategies for serious eye damage/eye irritation testing. Most important, the DRD is an invaluable tool for any future activity involving the selection of reference chemicals.

  14. Saccadic eye movement performance as an indicator of driving ability in elderly drivers.

    PubMed

    Schmitt, Kai-Uwe; Seeger, Rolf; Fischer, Hartmut; Lanz, Christian; Muser, Markus; Walz, Felix; Schwarz, Urs

    2015-01-01

    Regular checking of the fitness to drive of elderly car-license holders is required in some countries, and this will become increasingly important as more countries face aging populations. The present study investigated whether the analysis of saccadic eye movements could be used as a screening method for the assessment of driving ability. Three different paradigms (prosaccades, antisaccades, and visuovisual interactive (VVI) saccades) were used to test saccadic eye movements in 144 participants split into four groups: elderly drivers who came to the attention of road authorities for suspected lack of fitness to drive, a group of elderly drivers who served as a comparison group, a group of neurology patients with established brain lesion diagnoses, and a young comparison group. The group of elderly drivers with suspected deficits in driving skills also underwent a medical examination and a practical on-road driving test. The results of the saccadic eye tests of the different groups were compared. Antisaccade results indicated a strong link to driving behaviour: elderly drivers who were not fit to drive exhibited a poor performance on the antisaccade task and the performance in the VVI task was also clearly poorer in this group. Testing saccadic eye movements appears to be a promising and efficient method for screening large numbers of people such as elderly drivers. This study indicated a link between antisaccade performance and the ability to drive. Hence, measuring saccadic eye movements should be considered as a tool for screening the fitness to drive.

  15. Driving experience and special skills reflected in eye movements

    NASA Astrophysics Data System (ADS)

    Paeglis, Roberts; Bluss, Kristaps; Atvars, Aigars

    2011-10-01

    When driving a vehicle, people use the central vision both to plan ahead and monitor their performance feedback (research by Donges, 1978 [1], and after). Discussion is ongoing if making eye movements do more than gathering information. Moving eyes may also prepare the following body movements like steering. Different paradigms exist to explore vision in driving. Our perspective was to quantify eye movements and fixation patterns of different proficiency individuals, a driving learner, a novice, an experienced driver and a European level car racer. Thus for safety reasons we started by asking them to follow a video tour through a known city, remote from an infrared eye tracker sampling at 250 Hz. We report that gaze strategy of an experienced driver differs qualitatively from that of an automobile sports master. Quantitative differences only were found between the latter and a driving learner or a novice driver. Experience in a motor action provides skills different from sports training. We are aiming at testing this finding in real world driving.

  16. A Link Between Attentional Function, Effective Eye Movements, and Driving Ability

    PubMed Central

    2016-01-01

    The misallocation of driver visual attention has been suggested as a major contributing factor to vehicle accidents. One possible reason is that the relatively high cognitive demands of driving limit the ability to efficiently allocate gaze. We present an experiment that explores the relationship between attentional function and visual performance when driving. Drivers performed 2 variations of a multiple-object tracking task targeting aspects of cognition including sustained attention, dual-tasking, covert attention, and visuomotor skill. They also drove a number of courses in a driving simulator. Eye movements were recorded throughout. We found that individuals who performed better in the cognitive tasks exhibited more effective eye movement strategies when driving, such as scanning more of the road, and they also exhibited better driving performance. We discuss the potential link between an individual’s attentional function, effective eye movements, and driving ability. We also discuss the use of a visuomotor task in assessing driving behavior. PMID:27893270

  17. The Enright phenomenon. Stereoscopic distortion of perceived driving speed induced by monocular pupil dilation.

    PubMed

    Carkeet, Andrew; Wood, Joanne M; McNeill, Kylie M; McNeill, Hamish J; James, Joanna A; Holder, Leigh S

    The Enright phenomenon describes the distortion in speed perception experienced by an observer looking sideways from a moving vehicle when viewing with interocular differences in retinal image brightness, usually induced by neutral density filters. We investigated whether the Enright phenomenon could be induced with monocular pupil dilation using tropicamide. We tested 17 visually normal young adults on a closed road driving circuit. Participants were asked to travel at Goal Speeds of 40km/h and 60km/h while looking sideways from the vehicle with: (i) both eyes with undilated pupils; (ii) both eyes with dilated pupils; (iii) with the leading eye only dilated; and (iv) the trailing eye only dilated. For each condition we recorded actual driving speed. With the pupil of the leading eye dilated participants drove significantly faster (by an average of 3.8km/h) than with both eyes dilated (p=0.02); with the trailing eye dilated participants drove significantly slower (by an average of 3.2km/h) than with both eyes dilated (p<0.001). The speed, with the leading eye dilated, was faster by an average of 7km/h than with the trailing eye dilated (p<0.001). There was no significant difference between driving speeds when viewing with both eyes either dilated or undilated (p=0.322). Our results are the first to show a measurable change in driving behaviour following monocular pupil dilation and support predictions based on the Enright phenomenon. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  18. Monitoring sleepiness with on-board electrophysiological recordings for preventing sleep-deprived traffic accidents.

    PubMed

    Papadelis, Christos; Chen, Zhe; Kourtidou-Papadeli, Chrysoula; Bamidis, Panagiotis D; Chouvarda, Ioanna; Bekiaris, Evangelos; Maglaveras, Nikos

    2007-09-01

    The objective of this study is the development and evaluation of efficient neurophysiological signal statistics, which may assess the driver's alertness level and serve as potential indicators of sleepiness in the design of an on-board countermeasure system. Multichannel EEG, EOG, EMG, and ECG were recorded from sleep-deprived subjects exposed to real field driving conditions. A number of severe driving errors occurred during the experiments. The analysis was performed in two main dimensions: the macroscopic analysis that estimates the on-going temporal evolution of physiological measurements during the driving task, and the microscopic event analysis that focuses on the physiological measurements' alterations just before, during, and after the driving errors. Two independent neurophysiologists visually interpreted the measurements. The EEG data were analyzed by using both linear and non-linear analysis tools. We observed the occurrence of brief paroxysmal bursts of alpha activity and an increased synchrony among EEG channels before the driving errors. The alpha relative band ratio (RBR) significantly increased, and the Cross Approximate Entropy that quantifies the synchrony among channels also significantly decreased before the driving errors. Quantitative EEG analysis revealed significant variations of RBR by driving time in the frequency bands of delta, alpha, beta, and gamma. Most of the estimated EEG statistics, such as the Shannon Entropy, Kullback-Leibler Entropy, Coherence, and Cross-Approximate Entropy, were significantly affected by driving time. We also observed an alteration of eyes blinking duration by increased driving time and a significant increase of eye blinks' number and duration before driving errors. EEG and EOG are promising neurophysiological indicators of driver sleepiness and have the potential of monitoring sleepiness in occupational settings incorporated in a sleepiness countermeasure device. The occurrence of brief paroxysmal bursts of alpha activity before severe driving errors is described in detail for the first time. Clear evidence is presented that eye-blinking statistics are sensitive to the driver's sleepiness and should be considered in the design of an efficient and driver-friendly sleepiness detection countermeasure device.

  19. Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive

    PubMed Central

    Spreng, Lucie; Favrat, Bernard; Borruat, François-Xavier; Vaucher, Paul

    2018-01-01

    Objectives The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. Design A predictive cross-sectional study. Setting Volunteer participants to a drivers’ refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. Participants 162 drivers, male and female, aged 70 years or older. Clinical predictors We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. Outcomes We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Results Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R2=0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R2=0.004, P=0.454; CS: R2=0.006, P=0.332). Conclusion CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study. PMID:29374663

  20. Evaluation of methods for the assessment of attention while driving.

    PubMed

    Kircher, Katja; Ahlstrom, Christer

    2018-05-01

    The ability to assess the current attentional state of the driver is important for many aspects of driving, not least in the field of partial automation for transfer of control between vehicle and driver. Knowledge about the driver's attentional state is also necessary for the assessment of the effects of additional tasks on attention. The objective of this paper is to evaluate different methods that can be used to assess attention, first theoretically, and then empirically in a controlled field study and in the laboratory. Six driving instructors participated in all experimental conditions of the study, delivering within-subjects data for all tested methods. Additional participants were recruited for some of the conditions. The test route consisted of 14km of motorway with low to moderate traffic, which was driven three times per participant per condition. The on-road conditions were: baseline, driving with eye tracking and self-paced visual occlusion, and driving while thinking aloud. The laboratory conditions were: Describing how attention should be distributed on a motorway, and thinking aloud while watching a video from the baseline drive. The results show that visual occlusion, especially in combination with eye tracking, was appropriate for assessing spare capacity. The think aloud protocol was appropriate to gain insight about the driver's actual mental representation of the situation at hand. Expert judgement in the laboratory was not reliable for the assessment of drivers' attentional distribution in traffic. Across all assessment techniques, it is evident that meaningful assessment of attention in a dynamic traffic situation can only be achieved when the infrastructure layout, surrounding road users, and intended manoeuvres are taken into account. This requires advanced instrumentation of the vehicle, and subsequent data reduction, analysis and interpretation are demanding. In conclusion, driver attention assessment in real traffic is a complex task, but a combination of visual occlusion, eye tracking and thinking aloud is a promising combination of methods to come further on the way. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Glaucoma and Driving: On-Road Driving Characteristics

    PubMed Central

    Wood, Joanne M.; Black, Alex A.; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    Purpose To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Methods Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Results Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Conclusions Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness. PMID:27472221

  2. Glaucoma and Driving: On-Road Driving Characteristics.

    PubMed

    Wood, Joanne M; Black, Alex A; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

  3. First and second eye cataract surgery and driver self-regulation among older drivers with bilateral cataract: a prospective cohort study.

    PubMed

    Agramunt, Seraina; Meuleners, Lynn B; Fraser, Michelle L; Chow, Kyle C; Ng, Jonathon Q; Raja, Vignesh

    2018-02-17

    Driving a car is the most common form of transport among the older population. Common medical conditions such as cataract, increase with age and impact on the ability to drive. To compensate for visual decline, some cataract patients may self-regulate their driving while waiting for cataract surgery. However, little is known about the self-regulation practices of older drivers throughout the cataract surgery process. The aim of this study is to assess the impact of first and second eye cataract surgery on driver self-regulation practices, and to determine which objective measures of vision are associated with driver self-regulation. Fifty-five older drivers with bilateral cataract aged 55+ years were assessed using the self-reported Driving Habits Questionnaire, the Mini-Mental State Examination and three objective visual measures in the month before cataract surgery, at least one to three months after first eye cataract surgery and at least one month after second eye cataract surgery. Participants' natural driving behaviour in four driving situations was also examined for one week using an in-vehicle monitoring device. Two separate Generalised Estimating Equation logistic models were undertaken to assess the impact of first and second eye cataract surgery on driver-self-regulation status and which changes in visual measures were associated with driver self-regulation status. The odds of being a self-regulator in at least one driving situation significantly decreased by 70% after first eye cataract surgery (OR: 0.3, 95% CI: 0.1-0.7) and by 90% after second eye surgery (OR: 0.1, 95% CI: 0.1-0.4), compared to before first eye surgery. Improvement in contrast sensitivity after cataract surgery was significantly associated with decreased odds of self-regulation (OR: 0.02, 95% CI: 0.01-0.4). The findings provide a strong rationale for providing timely first and second eye cataract surgery for older drivers with bilateral cataract, in order to improve their mobility and independence.

  4. Assessment of Attentional Workload while Driving by Eye-fixation-related Potentials

    NASA Astrophysics Data System (ADS)

    Takeda, Yuji; Yoshitsugu, Noritoshi; Itoh, Kazuya; Kanamori, Nobuhiro

    How do drivers cope with the attentional workload of in-vehicle information technology? In the present study, we propose a new psychophysiological measure for assessing drivers' attention: eye-fixation-related potential (EFRP). EFRP is a kind of event-related brain potential measurable at the eye-movement situation that reflects how closely observers examine visual information at the eye-fixated position. In the experiment, the effects of verbal working memory load and spatial working memory load during simulated driving were examined by measuring the number of saccadic eye-movements and EFRP as the indices of drivers' attention. The results showed that the spatial working memory load affected both the number of saccadic eye-movements and the amplitude of the P100 component of EFRP, whereas the verbal working memory load affected only the number of saccadic eye-movements. This implies that drivers can perform time-sharing processing between driving and the verbal working memory task, but the decline of accuracy of visual processing during driving is inescapable when the spatial working memory load is given. The present study suggests that EFRP can provide a new index of drivers' attention, other than saccadic eye-movements.

  5. Driving simulation in the clinic: testing visual exploratory behavior in daily life activities in patients with visual field defects.

    PubMed

    Hamel, Johanna; Kraft, Antje; Ohl, Sven; De Beukelaer, Sophie; Audebert, Heinrich J; Brandt, Stephan A

    2012-09-18

    Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily life, despite similar visual deficits. We assume this could be due to variable development of compensatory strategies such as altered visual scanning behavior. Scanning compensatory therapy (SCT) is studied as part of the visual training after infarction next to vision restoration therapy. SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy(1), not only in natural search tasks but also in mastering daily life activities(2). Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition(3). Martin et al.(4) and Hayhoe et al.(5) showed that behavior demonstrated in a laboratory setting cannot be assigned easily to a natural condition. Hence, our goal was to develop a study set-up which uncovers different compensatory oculomotor strategies quickly in a realistic testing situation: Patients are tested in the clinical environment in a driving simulator. SILAB software (Wuerzburg Institute for Traffic Sciences GmbH (WIVW)) was used to program driving scenarios of varying complexity and recording the driver's performance. The software was combined with a head mounted infrared video pupil tracker, recording head- and eye-movements (EyeSeeCam, University of Munich Hospital, Clinical Neurosciences). The positioning of the patient in the driving simulator and the positioning, adjustment and calibration of the camera is demonstrated. Typical performances of a patient with and without compensatory strategy and a healthy control are illustrated in this pilot study. Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. Compensatory gaze behavior in a patient leads to a driving performance comparable to a healthy control, while the performance of a patient without compensatory behavior is significantly worse. The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential.

  6. Integrated Eye Tracking and Neural Monitoring for Enhanced Assessment of Mild TBI

    DTIC Science & Technology

    2015-04-01

    virtual reality driving simulator data acquisition. Data collection for the pilot study is nearly complete and data analyses are currently under way...Training for primary study procedures including neuropsychological testing, eye- tracking, virtual reality driving simulator, and EEG data acquisition is...the virtual reality driving simulator. Participants are instructed to drive along a coastal highway while performing the target detection task

  7. Older drivers and rapid deceleration events: Salisbury Eye Evaluation Driving Study.

    PubMed

    Keay, Lisa; Munoz, Beatriz; Duncan, Donald D; Hahn, Daniel; Baldwin, Kevin; Turano, Kathleen A; Munro, Cynthia A; Bandeen-Roche, Karen; West, Sheila K

    2013-09-01

    Drivers who rapidly change speed while driving may be more at risk for a crash. We sought to determine the relationship of demographic, vision, and cognitive variables with episodes of rapid decelerations during five days of normal driving in a cohort of older drivers. In the Salisbury Eye Evaluation Driving Study, 1425 older drivers aged 67-87 were recruited from the Maryland Motor Vehicle Administration's rolls for licensees in Salisbury, Maryland. Participants had several measures of vision tested: visual acuity, contrast sensitivity, visual fields, and the attentional visual field. Participants were also tested for various domains of cognitive function including executive function, attention, psychomotor speed, and visual search. A custom created driving monitoring system (DMS) was used to capture rapid deceleration events (RDEs), defined as at least 350 milli-g deceleration, during a five day period of monitoring. The rate of RDE per mile driven was modeled using a negative binomial regression model with an offset of the logarithm of the number of miles driven. We found that 30% of older drivers had one or more RDE during a five day period, and of those, about 1/3 had four or more. The rate of RDE per mile driven was highest for those drivers driving<59 miles during the 5-day period of monitoring. However, older drivers with RDE's were more likely to have better scores in cognitive tests of psychomotor speed and visual search, and have faster brake reaction time. Further, greater average speed and maximum speed per driving segment was protective against RDE events. In conclusion, contrary to our hypothesis, older drivers who perform rapid decelerations tend to be more "fit", with better measures of vision and cognition compared to those who do not have events of rapid deceleration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Older Drivers and Rapid Deceleration Events: Salisbury Eye Evaluation Driving Study

    PubMed Central

    Keay, Lisa; Munoz, Beatriz; Duncan, Donald D; Hahn, Daniel; Baldwin, Kevin; Turano, Kathleen A; Munro, Cynthia A; Bandeen-Roche, Karen; West, Sheila K

    2012-01-01

    Drivers who rapidly change speed while driving may be more at risk for a crash. We sought to determine the relationship of demographic, vision, and cognitive variables with episodes of rapid decelerations during five days of normal driving in a cohort of older drivers. In the Salisbury Eye Evaluation Driving Study, 1425 older drivers ages 67 to 87 were recruited from the Maryland Motor Vehicle Administration’s rolls for licensees in Salisbury, Maryland. Participants had several measures of vision tested: visual acuity, contrast sensitivity, visual fields, and the attentional visual field. Participants were also tested for various domains of cognitive function including executive function, attention, psychomotor speed, and visual search. A custom created Driving Monitor System (DMS) was used to capture rapid deceleration events (RDE), defined as at least 350 milli-g deceleration, during a five day period of monitoring. The rate of RDE per mile driven was modeled using a negative binomial regression model with an offset of the logarithm of the number of miles driven. We found that 30% of older drivers had one or more RDE during a five day period, and of those, about 1/3 had four or more. The rate of RDE per mile driven was highest for those drivers driving <59 miles during the 5-day period of monitoring. However, older drivers with RDE’s were more likely to have better scores in cognitive tests of psychomotor speed and visual search, and have faster brake reaction time. Further, greater average speed and maximum speed per driving segment was protective against RDE events. In conclusion, contrary to our hypothesis, older drivers who perform rapid decelerations tend to be more “fit”, with better measures of vision and cognition compared to those who do not have events of rapid deceleration. PMID:22742775

  9. Molecular medicine in ophthalmic care.

    PubMed

    Richer, Stuart; Stiles, William; Thomas, Carla

    2009-12-01

    Lipofuscin is the most consistent and phylogenically constant morphologic marker of cellular aging. Autofluorescence of the A2E fluorophore within retinal pigment epithelial (RPE) lipofuscin affords the opportunity for noninvasive evaluation of age- and disease-related pathophysiological changes in the human retina. It is being used in National Eye Institute/Age-Related Eye Disease Study II to evaluate age-related macular degeneration (AMD) geographic atrophy expansion. Experiments show lipofuscin can be reversed in cell culture and animal models in heart, brain, spinal cord, and retinal tissues, using an array of antioxidants and iron chelators. An 80-year-old man with a gastric resection presented with complaints of unremitting night driving difficulty despite treatment with lutein and omega III fatty acids. Notable parafoveal deposition of retinal lipofuscin by 50 degrees fundus auto-fluorescence (580 nm excitation/660 barrier filters) and concurrent abnormalities in non-Snellen measures of visual function-Contrast Sensitivity Function, 6.5 degrees large field tritan threshold, 10 degrees threshold visual fields, and deficits in the National Institutes of Health/National Eye Institute Visual Function Questionnaire (VFQ) 25 subjective night driving/mental health subscale questionnaire were obtained. The patient was placed on an over-the-counter daily oral polyphenolic mixture containing resveratrol and re-evaluated 5 months later. The data reveal improvements in all measures of visual function, subjective improvement in vision and mental functioning on the VFQ 25, and visible clearing of RPE lipofuscin. To our knowledge, we believe this to be the first reported human clinical case of lipofuscin reversal in the human eye correlated with measured clinical and subjective improvement in visual and mental function after nutraceutical intervention.

  10. Examining drivers' eye glance patterns during distracted driving: Insights from scanning randomness and glance transition matrix.

    PubMed

    Wang, Yuan; Bao, Shan; Du, Wenjun; Ye, Zhirui; Sayer, James R

    2017-12-01

    Visual attention to the driving environment is of great importance for road safety. Eye glance behavior has been used as an indicator of distracted driving. This study examined and quantified drivers' glance patterns and features during distracted driving. Data from an existing naturalistic driving study were used. Entropy rate was calculated and used to assess the randomness associated with drivers' scanning patterns. A glance-transition proportion matrix was defined to quantity visual search patterns transitioning among four main eye glance locations while driving (i.e., forward on-road, phone, mirrors and others). All measurements were calculated within a 5s time window under both cell phone and non-cell phone use conditions. Results of the glance data analyses showed different patterns between distracted and non-distracted driving, featured by a higher entropy rate value and highly biased attention transferring between forward and phone locations during distracted driving. Drivers in general had higher number of glance transitions, and their on-road glance duration was significantly shorter during distracted driving when compared to non-distracted driving. Results suggest that drivers have a higher scanning randomness/disorder level and shift their main attention from surrounding areas towards phone area when engaging in visual-manual tasks. Drivers' visual search patterns during visual-manual distraction with a high scanning randomness and a high proportion of eye glance transitions towards the location of the phone provide insight into driver distraction detection. This will help to inform the design of in-vehicle human-machine interface/systems. Copyright © 2017. Published by Elsevier Ltd.

  11. MAPK Target Sites of Eyes Absent Are Not Required for Eye Development or Survival in Drosophila

    PubMed Central

    Jusiak, Barbara; Abulimiti, Abuduaini; Haelterman, Nele; Chen, Rui; Mardon, Graeme

    2012-01-01

    Eyes absent (Eya) is a highly conserved transcription cofactor and protein phosphatase that plays an essential role in eye development and survival in Drosophila. Ectopic eye induction assays using cDNA transgenes have suggested that mitogen activated protein kinase (MAPK) activates Eya by phosphorylating it on two consensus target sites, S402 and S407, and that this activation potentiates the ability of Eya to drive eye formation. However, this mechanism has never been tested in normal eye development. In the current study, we generated a series of genomic rescue transgenes to investigate how loss- and gain-of-function mutations at these two MAPK target sites within Eya affect Drosophila survival and normal eye formation: eya+GR, the wild-type control; eyaSAGR, which lacks phosphorylation at the two target residues; and eyaSDEGR, which contains phosphomimetic amino acids at the same two residues. Contrary to the previous studies in ectopic eye development, all eya genomic transgenes tested rescue both eye formation and survival equally effectively. We conclude that, in contrast to ectopic eye formation, MAPK-mediated phosphorylation of Eya on S402 and S407 does not play a role in normal development. This is the first study in Drosophila to evaluate the difference in outcomes between genomic rescue and ectopic cDNA-based overexpression of the same gene. These findings indicate similar genomic rescue strategies may prove useful for re-evaluating other long-standing Drosophila developmental models. PMID:23251383

  12. Useful field of view in simulated driving: Reaction times and eye movements of drivers

    PubMed Central

    Seya, Yasuhiro; Nakayasu, Hidetoshi; Yagi, Tadasu

    2013-01-01

    To examine the spatial distribution of a useful field of view (UFOV) in driving, reaction times (RTs) and eye movements were measured in simulated driving. In the experiment, a normal or mirror-reversed letter “E” was presented on driving images with different eccentricities and directions from the current gaze position. The results showed significantly slower RTs in the upper and upper left directions than in the other directions. The RTs were significantly slower in the left directions than in the right directions. These results suggest that the UFOV in driving may be asymmetrical among the meridians in the visual field. PMID:24349688

  13. The effect of male teenage passengers on male teenage drivers: findings from a driving simulator study

    PubMed Central

    Ouimet, Marie Claude; Pradhan, Anuj K.; Simons-Morton, Bruce G.; Divekar, Gautam; Mehranian, Hasmik; Fisher, Donald L.

    2014-01-01

    Studies have shown that teenage drivers are less attentive, more frequently exhibit risky driving behavior, and have a higher fatal crash risk in the presence of peers. The effects of direct peer pressure and conversation on young drivers have been examined. Little is known about the impact on driving performance of the presence of a non-interacting passenger and subtle modes of peer influence, such as perceived social norms. The goal of this study was to examine if teenagers would engage in more risky driving practices and be less attentive in the presence of a passenger (vs. driving alone) as well as with a risk-accepting (vs. risk-averse) passenger. A confederate portrayed the passenger's characteristics mainly by his non-verbal attitude. The relationship between driver characteristics and driving behavior in the presence of a passenger was also examined. Thirty-six male participants aged 16-17 years old were randomly assigned to drive with a risk-accepting or risk-averse passenger. Main outcomes included speed, headway, gap acceptance, eye glances at hazards, and horizontal eye movement. Driver characteristics such as tolerance of deviance, susceptibility to peer pressure, and self-esteem were measured. Compared to solo driving, the presence of a passenger was associated with significantly fewer eye glances at hazards and a trend for fewer horizontal eye movements. Contrary to the hypothesis, however, passenger presence was associated with a greater number of vehicles before initiating a left turn. Results also showed, contrary to the hypothesis, that participants with the risk-accepting passenger maintained significantly longer headway with the lead vehicle and engaged in more eye glances at hazards than participants with the risk-averse passenger. Finally, when driving with the passenger, earlier initiation of a left turn in a steady stream of oncoming vehicles was significantly associated with higher tolerance of deviance and susceptibility to peer pressure, while fewer eye glances at hazards was linked to lower self-esteem. While the results of this study were mixed, they suggest that the presence of a teenage passenger can affect some aspects of teenage driver behavior even in the absence of overt pressure and distraction. Results are discussed in relation to theoretical concepts of social influence and social facilitation models. PMID:23727554

  14. Secondary Behavior of Drivers on Cell Phones.

    PubMed

    Farmer, Charles M; Klauer, Sheila G; McClafferty, Julie A; Guo, Feng

    2015-01-01

    The objective of this study was to determine whether cell phone use by drivers leads to changes in the frequency of other types of potentially distracting behavior. There were 2 main questions of interest: (1) As each driver changes cell phone use, does he or she change the amount of driving time spent on other distracting behavior? (2) As each driver changes cell phone use, does he or she change the amount of driving time spent looking away from the driving task? Day-to-day driving behavior of 105 volunteer subjects was monitored over a period of 1 year. The amount of driving time during each trip spent on tasks secondary to driving (or looking away from the driving task) was correlated to the amount of time on a cell phone, taking into account the relationships among trips taken by the same driver. Drivers spent 42% of the time engaging in at least one secondary activity. Drivers were talking on a cell phone 7% of the time, interacting in some other way with a cell phone 5% of the time, and engaging in some other secondary activity (sometimes in conjunction with cell phone use) 33% of the time. Other than cell phone use, the most common secondary activities were interacting with a passenger (12% of driving time), holding but not otherwise interacting with an object (6%), and talking/singing/dancing to oneself (5%). Drivers were looking straight forward 81% of the time, forward left or right 5% of time, in a mirror 4% of the time, and elsewhere (eyes off driving task) 10% of time. On average, for each 1 percentage point increase in cell phone talking, the other secondary behavior rate decreased by 0.28 percentage points (P <.0001), and the rate of eyes off driving task decreased by 0.02 percentage points (P =.0067). For each 1 percentage point increase in the amount of other cell phone interaction per trip, the other secondary behavior rate decreased by 0.08 percentage points (P =.0558), but the rate of eyes off driving task increased by 0.06 percentage points (P <.0001). Although using a cell phone can be distracting from the driving task, other secondary activities can be equally or more distracting, at least as measured by eye glances away from the road ahead and mirrors. In this group of drivers, dialing, reaching for, and answering the cell phone were associated with increased eyes off driving task, as opposed to the decrease in eyes off driving task associated with talking on the phone. Predictions about the effect of cell phone usage on driver distraction need to consider what other behavior is being displaced by the time spent on the phone. A focus by researchers, policy-makers, and the media on the distraction of using cell phones while driving may lead drivers to disregard the risk of other secondary behavior that is even more distracting.

  15. The effects of using a portable music player on simulated driving performance and task-sharing strategies.

    PubMed

    Young, Kristie L; Mitsopoulos-Rubens, Eve; Rudin-Brown, Christina M; Lenné, Michael G

    2012-07-01

    This study examined the effects of performing scrollable music selection tasks using a portable music player (iPod Touch™) on simulated driving performance and task-sharing strategies, as evidenced through eye glance behaviour and secondary task performance. A total of 37 drivers (18-48 yrs) completed the PC-based MUARC Driver Distraction Test (DDT) while performing music selection tasks on an iPod Touch. Drivers' eye glance behaviour was examined using faceLAB eye tracking equipment. Results revealed that performing music search tasks while driving increased the amount of time that drivers spent with their eyes off the roadway and decreased their ability to maintain a constant lane position and time headway from a lead vehicle. There was also evidence, however, that drivers attempted to regulate their behaviour when distracted by decreasing their speed and taking a large number of short glances towards the device. Overall, results suggest that performing music search tasks while driving is problematic and steps to prohibit this activity should be taken. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  16. The brain stem saccadic burst generator encodes gaze in three-dimensional space.

    PubMed

    Van Horn, Marion R; Sylvestre, Pierre A; Cullen, Kathleen E

    2008-05-01

    When we look between objects located at different depths the horizontal movement of each eye is different from that of the other, yet temporally synchronized. Traditionally, a vergence-specific neuronal subsystem, independent from other oculomotor subsystems, has been thought to generate all eye movements in depth. However, recent studies have challenged this view by unmasking interactions between vergence and saccadic eye movements during disconjugate saccades. Here, we combined experimental and modeling approaches to address whether the premotor command to generate disconjugate saccades originates exclusively in "vergence centers." We found that the brain stem burst generator, which is commonly assumed to drive only the conjugate component of eye movements, carries substantial vergence-related information during disconjugate saccades. Notably, facilitated vergence velocities during disconjugate saccades were synchronized with the burst onset of excitatory and inhibitory brain stem saccadic burst neurons (SBNs). Furthermore, the time-varying discharge properties of the majority of SBNs (>70%) preferentially encoded the dynamics of an individual eye during disconjugate saccades. When these experimental results were implemented into a computer-based simulation, to further evaluate the contribution of the saccadic burst generator in generating disconjugate saccades, we found that it carries all the vergence drive that is necessary to shape the activity of the abducens motoneurons to which it projects. Taken together, our results provide evidence that the premotor commands from the brain stem saccadic circuitry, to the target motoneurons, are sufficient to ensure the accurate control shifts of gaze in three dimensions.

  17. Simulated Driving Assessment (SDA) for Teen Drivers: Results from a Validation Study

    PubMed Central

    McDonald, Catherine C.; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas S.; Lee, Yi-Ching; Winston, Zachary; Winston, Flaura K.

    2015-01-01

    Background Driver error and inadequate skill are common critical reasons for novice teen driver crashes, yet few validated, standardized assessments of teen driving skills exist. The purpose of this study was to evaluate the construct and criterion validity of a newly developed Simulated Driving Assessment (SDA) for novice teen drivers. Methods The SDA's 35-minute simulated drive incorporates 22 variations of the most common teen driver crash configurations. Driving performance was compared for 21 inexperienced teens (age 16–17 years, provisional license ≤90 days) and 17 experienced adults (age 25–50 years, license ≥5 years, drove ≥100 miles per week, no collisions or moving violations ≤3 years). SDA driving performance (Error Score) was based on driving safety measures derived from simulator and eye-tracking data. Negative driving outcomes included simulated collisions or run-off-the-road incidents. A professional driving evaluator/instructor reviewed videos of SDA performance (DEI Score). Results The SDA demonstrated construct validity: 1.) Teens had a higher Error Score than adults (30 vs. 13, p=0.02); 2.) For each additional error committed, the relative risk of a participant's propensity for a simulated negative driving outcome increased by 8% (95% CI: 1.05–1.10, p<0.01). The SDA demonstrated criterion validity: Error Score was correlated with DEI Score (r=−0.66, p<0.001). Conclusions This study supports the concept of validated simulated driving tests like the SDA to assess novice driver skill in complex and hazardous driving scenarios. The SDA, as a standard protocol to evaluate teen driver performance, has the potential to facilitate screening and assessment of teen driving readiness and could be used to guide targeted skill training. PMID:25740939

  18. The anti-fatigue driving system design based on the eye blink detect

    NASA Astrophysics Data System (ADS)

    Yang, Shuyu; Song, Xin; Zhang, Li; Yu, Jie

    2017-01-01

    Traffic accident is one of the severe social problems in the world, but the appraisal and prevention of the fatigue driving is still a difficult problem that can not be solved. This paper is to study the results of fatigue driving and the existing antifatigue driving products, collecting brain wave with the TGAM (ThinkGear AM) Brain Wave Sensor Chip. We analyze the collected waveform based on eye blink detect algorithm to work out current situation of the driver. According to the analysis results, Sound Module and controllable speed car will make a series of feedback. Finally, an effective Anti- Fatigue Driving System is designed based on all above.

  19. [Attention to speed and guide traffic signs with eye movements].

    PubMed

    Conchillo Jiménez, Ángela; Pérez-Moreno, Elisa; Recarte Goldaracena, Miguel Ángel

    2010-11-01

    The goal of this research is to describe the visual search patterns for diverse traffic signs. Twelve drivers of both genders and different driving experience levels took part in real driving research with an instrumented car provided with an eye-tracking system. Looking at signs has a weak relation with speed reduction in cases where actual driving speed was higher. Nevertheless, among the people who looked at the sign, the percentage of those who reduce the speed below the limit is greater than of those who do not look at the sign. Guide traffic signs, particularly those mounted over the road, are more frequently glanced at than speed limit signs, with a glance duration of more than one second, in sequences of more than two consecutive fixations. Implications for driving and the possibilities and limitations of eye movement analysis for traffic sign research are discussed.

  20. Impact of dry eye syndrome on vision-related quality of life.

    PubMed

    Miljanović, Biljana; Dana, Reza; Sullivan, David A; Schaumberg, Debra A

    2007-03-01

    To evaluate the impact of dry eye syndrome (DES) on vision-associated quality of life. Cross-sectional study. We identified 450 participants in the Women's Health Study (WHS) and 240 participants in the Physicians' Health Study (PHS) and sent a supplementary questionnaire asking how much their everyday activities were limited by symptoms of dry eye and to what degree problems with their eyes limited them in reading, driving, working at the computer, their professional activity, and watching television. By design, one-third of study subjects had clinically diagnosed DES or severe symptoms and two-thirds did not. We used logistic regression to examine relationships of DES with reported problems with everyday activities in each cohort and pooled estimates using meta-analysis methods. Of the participants invited, 85% completed the supplementary questionnaire, including 135 WHS and 55 PHS participants with DES, and 250 WHS and 149 PHS participants without DES. Controlling for age, diabetes, hypertension, and other factors, those with DES were more likely to report problems with reading ([odds ratio] OR = 3.64, 95% [confidence interval] CI 2.45 to 5.40, P < .0001); carrying out professional work (OR = 3.49, 95% CI 1.72 to 7.09, P= 0.001); using a computer (OR = 3.37, 95% CI 2.11 to 5.38, P < .0001); watching television (OR = 2.84, 95% CI 1.05 to 7.74, P = .04); driving during the day (OR = 2.80, 95% CI 1.58 to 4.96, P < .0001); and driving at night (OR = 2.20, 95% CI 1.48 to 3.28, P < .0001). DES is associated with a measurable adverse impact on several common and important tasks of daily living, further implicating this condition as an important public health problem deserving increased attention and resources.

  1. Is it reliable to assess visual attention of drivers affected by Parkinson's disease from the backseat?—a simulator study

    PubMed Central

    Lee, Hoe C.; Yanting Chee, Derserri; Selander, Helena; Falkmer, Torbjorn

    2012-01-01

    Background Current methods of determining licence retainment or cancellation is through on-road driving tests. Previous research has shown that occupational therapists frequently assess drivers’ visual attention while sitting in the back seat on the opposite side of the driver. Since the eyes of the driver are not always visible, assessment by eye contact becomes problematic. Such procedural drawbacks may challenge validity and reliability of the visual attention assessments. In terms of correctly classified attention, the aim of the study was to establish the accuracy and the inter-rater reliability of driving assessments of visual attention from the back seat. Furthermore, by establishing eye contact between the assessor and the driver through an additional mirror on the wind screen, the present study aimed to establish how much such an intervention would enhance the accuracy of the visual attention assessment. Methods Two drivers with Parkinson's disease (PD) and six control drivers drove a fixed route in a driving simulator while wearing a head mounted eye tracker. The eye tracker data showed where the foveal visual attention actually was directed. These data were time stamped and compared with the simultaneous manual scoring of the visual attention of the drivers. In four of the drivers, one with Parkinson's disease, a mirror on the windscreen was set up to arrange for eye contact between the driver and the assessor. Inter-rater reliability was performed with one of the Parkinson drivers driving, but without the mirror. Results Without mirror, the overall accuracy was 56% when assessing the three control drivers and with mirror 83%. However, for the PD driver without mirror the accuracy was 94%, whereas for the PD driver with a mirror the accuracy was 90%. With respect to the inter-rater reliability, a 73% agreement was found. Conclusion If the final outcome of a driving assessment is dependent on the subcategory of a protocol assessing visual attention, we suggest the use of an additional mirror to establish eye contact between the assessor and the driver. The clinicians’ observations on-road should not be a standalone assessment in driving assessments. Instead, eye trackers should be employed for further analyses and correlation in cases where there is doubt about a driver's attention. PMID:22461850

  2. On-road Driving Performance of Patients with Bilateral Moderate and Advanced Glaucoma

    PubMed Central

    Bhorade, Anjali M.; Yom, Victoria H.; Barco, Peggy; Wilson, Bradley; Gordon, Mae; Carr, David

    2017-01-01

    Purpose To compare on-road driving performance of patients with moderate or advanced glaucoma to controls and evaluate factors associated with unsafe driving. Design Case-control pilot study. Methods A consecutive sample of 21 patients with bilateral moderate or advanced glaucoma from Washington University, St. Louis, MO and 38 community-dwelling controls were enrolled. Participants, ages 55–90 years, underwent a comprehensive clinical evaluation by a trained occupational therapist and an on-road driving evaluation by a masked driver rehabilitation specialist. Overall driving performance of pass vs. marginal/fail and number of wheel and/or brake interventions were recorded. Results Fifty-two percent of glaucoma participants scored a marginal/fail compared to 21% of controls (odds ratio [OR], 4.1; 95% CI, 1.30–13.14;p=.02). Glaucoma participants had a higher risk of wheel interventions than controls (OR, 4.67; 95% CI, 1.03–21.17;p=.046). There were no differences detected between glaucoma participants who scored a pass vs. marginal/fail for visual field mean deviation of the better (p=.62) or worse (p=.88) eye, binocular distance (p=.15) or near (p=.23) visual acuity, contrast sensitivity (p=.28) or glare (p=.88). However, glaucoma participants with a marginal/fail score performed worse on Trail Making Tests A (p=.03) and B (p=.05), right-sided Jamar grip strength (p=.02), Rapid Pace Walk (p=.03), Braking Response Time (p=.03), and identifying traffic signs (p=.05). Conclusions and Relevance Patients with bilateral moderate or advanced glaucoma are at risk for unsafe driving – particularly those with impairments on psychometric and mobility tests. A comprehensive clinical assessment and on-road driving evaluation is recommended to effectively evaluate driving safety of these patients. PMID:26949136

  3. An exploratory study on the driving method of speech synthesis based on the human eye reading imaging data

    NASA Astrophysics Data System (ADS)

    Gao, Pei-pei; Liu, Feng

    2016-10-01

    With the development of information technology and artificial intelligence, speech synthesis plays a significant role in the fields of Human-Computer Interaction Techniques. However, the main problem of current speech synthesis techniques is lacking of naturalness and expressiveness so that it is not yet close to the standard of natural language. Another problem is that the human-computer interaction based on the speech synthesis is too monotonous to realize mechanism of user subjective drive. This thesis introduces the historical development of speech synthesis and summarizes the general process of this technique. It is pointed out that prosody generation module is an important part in the process of speech synthesis. On the basis of further research, using eye activity rules when reading to control and drive prosody generation was introduced as a new human-computer interaction method to enrich the synthetic form. In this article, the present situation of speech synthesis technology is reviewed in detail. Based on the premise of eye gaze data extraction, using eye movement signal in real-time driving, a speech synthesis method which can express the real speech rhythm of the speaker is proposed. That is, when reader is watching corpora with its eyes in silent reading, capture the reading information such as the eye gaze duration per prosodic unit, and establish a hierarchical prosodic pattern of duration model to determine the duration parameters of synthesized speech. At last, after the analysis, the feasibility of the above method is verified.

  4. Exploring eye movements in patients with glaucoma when viewing a driving scene.

    PubMed

    Crabb, David P; Smith, Nicholas D; Rauscher, Franziska G; Chisholm, Catharine M; Barbur, John L; Edgar, David F; Garway-Heath, David F

    2010-03-16

    Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for fitness to drive.

  5. Exploring Eye Movements in Patients with Glaucoma When Viewing a Driving Scene

    PubMed Central

    Crabb, David P.; Smith, Nicholas D.; Rauscher, Franziska G.; Chisholm, Catharine M.; Barbur, John L.; Edgar, David F.; Garway-Heath, David F.

    2010-01-01

    Background Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). Methodology/Principal Findings The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of ‘point-of-regard’ of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Conclusions/Significance Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for fitness to drive. PMID:20300522

  6. Deep Learning-Based Gaze Detection System for Automobile Drivers Using a NIR Camera Sensor.

    PubMed

    Naqvi, Rizwan Ali; Arsalan, Muhammad; Batchuluun, Ganbayar; Yoon, Hyo Sik; Park, Kang Ryoung

    2018-02-03

    A paradigm shift is required to prevent the increasing automobile accident deaths that are mostly due to the inattentive behavior of drivers. Knowledge of gaze region can provide valuable information regarding a driver's point of attention. Accurate and inexpensive gaze classification systems in cars can improve safe driving. However, monitoring real-time driving behaviors and conditions presents some challenges: dizziness due to long drives, extreme lighting variations, glasses reflections, and occlusions. Past studies on gaze detection in cars have been chiefly based on head movements. The margin of error in gaze detection increases when drivers gaze at objects by moving their eyes without moving their heads. To solve this problem, a pupil center corneal reflection (PCCR)-based method has been considered. However, the error of accurately detecting the pupil center and corneal reflection center is increased in a car environment due to various environment light changes, reflections on glasses surface, and motion and optical blurring of captured eye image. In addition, existing PCCR-based methods require initial user calibration, which is difficult to perform in a car environment. To address this issue, we propose a deep learning-based gaze detection method using a near-infrared (NIR) camera sensor considering driver head and eye movement that does not require any initial user calibration. The proposed system is evaluated on our self-constructed database as well as on open Columbia gaze dataset (CAVE-DB). The proposed method demonstrated greater accuracy than the previous gaze classification methods.

  7. Deep Learning-Based Gaze Detection System for Automobile Drivers Using a NIR Camera Sensor

    PubMed Central

    Naqvi, Rizwan Ali; Arsalan, Muhammad; Batchuluun, Ganbayar; Yoon, Hyo Sik; Park, Kang Ryoung

    2018-01-01

    A paradigm shift is required to prevent the increasing automobile accident deaths that are mostly due to the inattentive behavior of drivers. Knowledge of gaze region can provide valuable information regarding a driver’s point of attention. Accurate and inexpensive gaze classification systems in cars can improve safe driving. However, monitoring real-time driving behaviors and conditions presents some challenges: dizziness due to long drives, extreme lighting variations, glasses reflections, and occlusions. Past studies on gaze detection in cars have been chiefly based on head movements. The margin of error in gaze detection increases when drivers gaze at objects by moving their eyes without moving their heads. To solve this problem, a pupil center corneal reflection (PCCR)-based method has been considered. However, the error of accurately detecting the pupil center and corneal reflection center is increased in a car environment due to various environment light changes, reflections on glasses surface, and motion and optical blurring of captured eye image. In addition, existing PCCR-based methods require initial user calibration, which is difficult to perform in a car environment. To address this issue, we propose a deep learning-based gaze detection method using a near-infrared (NIR) camera sensor considering driver head and eye movement that does not require any initial user calibration. The proposed system is evaluated on our self-constructed database as well as on open Columbia gaze dataset (CAVE-DB). The proposed method demonstrated greater accuracy than the previous gaze classification methods. PMID:29401681

  8. Driver eye-scanning behavior at intersections at night.

    DOT National Transportation Integrated Search

    2009-10-01

    This research project analyzed drivers eye scanning behavior at night when approaching signalized : and unsignalized intersections using the data from a head-mounted eye-tracking system during open road : driving on a prescribed route. During the ...

  9. Characterizing Disease Burden and Progression of Geographic Atrophy Secondary to Age-Related Macular Degeneration.

    PubMed

    Chakravarthy, Usha; Bailey, Clare C; Johnston, Robert L; McKibbin, Martin; Khan, Rehna S; Mahmood, Sajjad; Downey, Louise; Dhingra, Narendra; Brand, Christopher; Brittain, Christopher J; Willis, Jeffrey R; Rabhi, Sarah; Muthutantri, Anushini; Cantrell, Ronald A

    2018-06-01

    To understand levels of disease burden and progression in a real-world setting among patients from the United Kingdom with bilateral geographic atrophy (GA) secondary to age-related macular degeneration (AMD). Retrospective cohort analysis of a multicenter electronic medical record (EMR) database. Patients who were aged ≥50 years with bilateral GA and no history of choroidal neovascularization (CNV) and who attended 1 of 10 clinical sites using the EMR. A deidentified data set was constructed from the records held at the 10 sites. An algorithm was used to extract cases with a GA diagnosis, of which 1901 had bilateral GA and form the basis of this report. A sample of records randomly selected from each center was used to validate disease definitions. Progression to blindness (visual acuity [VA] <20 letters or Snellen 3/60 in the better-seeing eye), driving ineligibility (VA ≤70 letters or Snellen 6/12 in the better-seeing eye), progression to CNV, loss of 10 or more letters, and mean change in VA over time. At first record of GA, 7.1% had a VA in the better-seeing eye equal to or lower than the cutoff for blindness registration and 71.1% had a VA that would have rendered them ineligible to drive. Over time, 16% became legally blind (median time to outcome, 6.2 years) and 66.7% became ineligible to drive (median time to outcome, 1.6 years). In the worse-seeing eye, 40.1% lost ≥10 letters in 2.4 years. Among patients with baseline and 24-month VA measurements, mean VA decline was 6.1 letters in the worse-seeing eye (n = 413) and 12.4 letters in the better-seeing eye (n = 414). The rate of progression to CNV in either eye was 7.4% per patient-year. At initial diagnosis, based on VA in the better-seeing eye, a high proportion of patients with bilateral GA were ineligible to drive and approximately 7% were eligible for UK blindness registration. The subsequent reduction in VA that occurred in the better-seeing eye would render a further two-thirds ineligible to drive. These findings emphasize the severity of the visual disability associated with GA secondary to AMD. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  10. Detecting eye movements in dynamic environments.

    PubMed

    Reimer, Bryan; Sodhi, Manbir

    2006-11-01

    To take advantage of the increasing number of in-vehicle devices, automobile drivers must divide their attention between primary (driving) and secondary (operating in-vehicle device) tasks. In dynamic environments such as driving, however, it is not easy to identify and quantify how a driver focuses on the various tasks he/she is simultaneously engaged in, including the distracting tasks. Measures derived from the driver's scan path have been used as correlates of driver attention. This article presents a methodology for analyzing eye positions, which are discrete samples of a subject's scan path, in order to categorize driver eye movements. Previous methods of analyzing eye positions recorded in a dynamic environment have relied completely on the manual identification of the focus of visual attention from a point of regard superimposed on a video of a recorded scene, failing to utilize information regarding movement structure in the raw recorded eye positions. Although effective, these methods are too time consuming to be easily used when the large data sets that would be required to identify subtle differences between drivers, under different road conditions, and with different levels of distraction are processed. The aim of the methods presented in this article are to extend the degree of automation in the processing of eye movement data by proposing a methodology for eye movement analysis that extends automated fixation identification to include smooth and saccadic movements. By identifying eye movements in the recorded eye positions, a method of reducing the analysis of scene video to a finite search space is presented. The implementation of a software tool for the eye movement analysis is described, including an example from an on-road test-driving sample.

  11. States Eyeing Expense of Hand-Scored Tests in Light of NCLB Rules

    ERIC Educational Resources Information Center

    Archer, Jeff

    2005-01-01

    When students put down their pencils at the end of Connecticut's testing each year, another intensive process begins. Hundreds of trained evaluators work day and night for about a month to score the written responses. Although expensive, the use of open-ended questions drives the kind of instruction that state leaders say they want in their…

  12. Night driving simulation in a randomized prospective comparison of Visian toric implantable collamer lens and conventional PRK for moderate to high myopic astigmatism.

    PubMed

    Schallhorn, Steven; Tanzer, David; Sanders, Donald R; Sanders, Monica; Brown, Mitch; Kaupp, Sandor E

    2010-05-01

    To compare changes in simulated night driving performance after Visian Toric Implantable Collamer Lens (TICL; STAAR Surgical) implantation and photorefractive keratectomy (PRK) for the correction of moderate to high myopic astigmatism. This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving conventional PRK (VISX Star S3 excimer laser) with mitomycin C (22 bilateral cases) for moderate to high myopia (-6.00 to -20.00 diopters[D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. As a substudy, 27 eyes of 14 TICL patients and 41 eyes of 21 PRK patients underwent a simulated night driving test. The detection and identification distances of road signs and hazards with the Night Driving Simulator (Vision Sciences Research Corp) were measured with and without a glare source before and 6 months after each procedure. No significant difference was noted in the pre- to postoperative Night Driving Simulator in detection distances with and without the glare source between the TICL and PRK groups. The differences in identification distances without glare were significantly better for business and traffic road signs and pedestrian hazards in the TICL group relative to the PRK group whereas with glare, only the pedestrian hazards were significantly better. A clinically relevant change of Night Driving Simulator performance (>0.5 seconds change in ability to identify tasks postoperatively) was significantly better in the TICL group (with and without glare) for all identification tasks. The TICL performed better than conventional PRK in the pre- to postoperative Night Driving Simulator testing with and without a glare source present. Copyright 2010, SLACK Incorporated.

  13. Eyes wide shopped: shopping situations trigger arousal in impulsive buyers.

    PubMed

    Serfas, Benjamin G; Büttner, Oliver B; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures.

  14. Visual Sensory and Visual-Cognitive Function and Rate of Crash and Near-Crash Involvement Among Older Drivers Using Naturalistic Driving Data

    PubMed Central

    Huisingh, Carrie; Levitan, Emily B.; Irvin, Marguerite R.; MacLennan, Paul; Wadley, Virginia; Owsley, Cynthia

    2017-01-01

    Purpose An innovative methodology using naturalistic driving data was used to examine the association between visual sensory and visual-cognitive function and rates of future crash or near-crash involvement among older drivers. Methods The Strategic Highway Research Program (SHRP2) Naturalistic Driving Study was used for this prospective analysis. The sample consisted of N = 659 drivers aged ≥70 years and study participation lasted 1 or 2 years for most participants. Distance and near visual acuity, contrast sensitivity, peripheral vision, visual processing speed, and visuospatial skills were assessed at baseline. Crash and near-crash involvement were based on video recordings and vehicle sensors. Poisson regression models were used to generate crude and adjusted rate ratios (RRs) and 95% confidence intervals, while accounting for person-miles of travel. Results After adjustment, severe impairment of the useful field of view (RR = 1.33) was associated with an increased rate of near-crash involvement. Crash, severe crash, and at-fault crash involvement were associated with impaired contrast sensitivity in the worse eye (RRs = 1.38, 1.54, and 1.44, respectively) and far peripheral field loss in both eyes (RRs = 1.74, 2.32, and 1.73, respectively). Conclusions Naturalistic driving data suggest that contrast sensitivity in the worse eye and far peripheral field loss in both eyes elevate the rates of crash involvement, and impaired visual processing speed elevates rates of near-crash involvement among older drivers. Naturalistic driving data may ultimately be critical for understanding the relationship between vision and driving safety. PMID:28605807

  15. Eye movements and hazard perception in active and passive driving

    PubMed Central

    Mackenzie, Andrew K.; Harris, Julie M.

    2015-01-01

    ABSTRACT Differences in eye movement patterns are often found when comparing passive viewing paradigms to actively engaging in everyday tasks. Arguably, investigations into visuomotor control should therefore be most useful when conducted in settings that incorporate the intrinsic link between vision and action. We present a study that compares oculomotor behaviour and hazard reaction times across a simulated driving task and a comparable, but passive, video-based hazard perception task. We found that participants scanned the road less during the active driving task and fixated closer to the front of the vehicle. Participants were also slower to detect the hazards in the driving task. Our results suggest that the interactivity of simulated driving places increased demand upon the visual and attention systems than simply viewing driving movies. We offer insights into why these differences occur and explore the possible implications of such findings within the wider context of driver training and assessment. PMID:26681913

  16. Simulated Driving Assessment (SDA) for teen drivers: results from a validation study.

    PubMed

    McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas S; Lee, Yi-Ching; Winston, Zachary; Winston, Flaura K

    2015-06-01

    Driver error and inadequate skill are common critical reasons for novice teen driver crashes, yet few validated, standardised assessments of teen driving skills exist. The purpose of this study is to evaluate the construct and criterion validity of a newly developed Simulated Driving Assessment (SDA) for novice teen drivers. The SDA's 35 min simulated drive incorporates 22 variations of the most common teen driver crash configurations. Driving performance was compared for 21 inexperienced teens (age 16-17 years, provisional license ≤90 days) and 17 experienced adults (age 25-50 years, license ≥5 years, drove ≥100 miles per week, no collisions or moving violations ≤3 years). SDA driving performance (Error Score) was based on driving safety measures derived from simulator and eye-tracking data. Negative driving outcomes included simulated collisions or run-off-the-road incidents. A professional driving evaluator/instructor (DEI Score) reviewed videos of SDA performance. The SDA demonstrated construct validity: (1) teens had a higher Error Score than adults (30 vs. 13, p=0.02); (2) For each additional error committed, the RR of a participant's propensity for a simulated negative driving outcome increased by 8% (95% CI 1.05 to 1.10, p<0.01). The SDA-demonstrated criterion validity: Error Score was correlated with DEI Score (r=-0.66, p<0.001). This study supports the concept of validated simulated driving tests like the SDA to assess novice driver skill in complex and hazardous driving scenarios. The SDA, as a standard protocol to evaluate teen driver performance, has the potential to facilitate screening and assessment of teen driving readiness and could be used to guide targeted skill training. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving

    PubMed Central

    Oka, Noriyuki; Yoshino, Kayoko; Yamamoto, Kouji; Takahashi, Hideki; Li, Shuguang; Sugimachi, Toshiyuki; Nakano, Kimihiko; Suda, Yoshihiro; Kato, Toshinori

    2015-01-01

    Objectives In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves), but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS). Research Design and Methods The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task). Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections. Results Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05), but cerebral oxygen exchange increased significantly more during left curves (p < 0.05) in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05) only in the right frontal eye field. Conclusions Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions. PMID:25993263

  18. Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving.

    PubMed

    Oka, Noriyuki; Yoshino, Kayoko; Yamamoto, Kouji; Takahashi, Hideki; Li, Shuguang; Sugimachi, Toshiyuki; Nakano, Kimihiko; Suda, Yoshihiro; Kato, Toshinori

    2015-01-01

    In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves), but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS). The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task). Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections. Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05), but cerebral oxygen exchange increased significantly more during left curves (p < 0.05) in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05) only in the right frontal eye field. Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions.

  19. Matching the oculomotor drive during head-restrained and head-unrestrained gaze shifts in monkey.

    PubMed

    Bechara, Bernard P; Gandhi, Neeraj J

    2010-08-01

    High-frequency burst neurons in the pons provide the eye velocity command (equivalently, the primary oculomotor drive) to the abducens nucleus for generation of the horizontal component of both head-restrained (HR) and head-unrestrained (HU) gaze shifts. We sought to characterize how gaze and its eye-in-head component differ when an "identical" oculomotor drive is used to produce HR and HU movements. To address this objective, the activities of pontine burst neurons were recorded during horizontal HR and HU gaze shifts. The burst profile recorded on each HU trial was compared with the burst waveform of every HR trial obtained for the same neuron. The oculomotor drive was assumed to be comparable for the pair yielding the lowest root-mean-squared error. For matched pairs of HR and HU trials, the peak eye-in-head velocity was substantially smaller in the HU condition, and the reduction was usually greater than the peak head velocity of the HU trial. A time-varying attenuation index, defined as the difference in HR and HU eye velocity waveforms divided by head velocity [alpha = (H(hr) - E(hu))/H] was computed. The index was variable at the onset of the gaze shift, but it settled at values several times greater than 1. The index then decreased gradually during the movement and stabilized at 1 around the end of gaze shift. These results imply that substantial attenuation in eye velocity occurs, at least partially, downstream of the burst neurons. We speculate on the potential roles of burst-tonic neurons in the neural integrator and various cell types in the vestibular nuclei in mediating the attenuation in eye velocity in the presence of head movements.

  20. Pursuit Eye-Movements in Curve Driving Differentiate between Future Path and Tangent Point Models

    PubMed Central

    Lappi, Otto; Pekkanen, Jami; Itkonen, Teemu H.

    2013-01-01

    For nearly 20 years, looking at the tangent point on the road edge has been prominent in models of visual orientation in curve driving. It is the most common interpretation of the commonly observed pattern of car drivers looking through a bend, or at the apex of the curve. Indeed, in the visual science literature, visual orientation towards the inside of a bend has become known as “tangent point orientation”. Yet, it remains to be empirically established whether it is the tangent point the drivers are looking at, or whether some other reference point on the road surface, or several reference points, are being targeted in addition to, or instead of, the tangent point. Recently discovered optokinetic pursuit eye-movements during curve driving can provide complementary evidence over and above traditional gaze-position measures. This paper presents the first detailed quantitative analysis of pursuit eye movements elicited by curvilinear optic flow in real driving. The data implicates the far zone beyond the tangent point as an important gaze target area during steady-state cornering. This is in line with the future path steering models, but difficult to reconcile with any pure tangent point steering model. We conclude that the tangent point steering models do not provide a general explanation of eye movement and steering during a curve driving sequence and cannot be considered uncritically as the default interpretation when the gaze position distribution is observed to be situated in the region of the curve apex. PMID:23894300

  1. Driving while using a smartphone-based mobility application: Evaluating the impact of three multi-choice user interfaces on visual-manual distraction.

    PubMed

    Louveton, N; McCall, R; Koenig, V; Avanesov, T; Engel, T

    2016-05-01

    Innovative in-car applications provided on smartphones can deliver real-time alternative mobility choices and subsequently generate visual-manual demand. Prior studies have found that multi-touch gestures such as kinetic scrolling are problematic in this respect. In this study we evaluate three prototype tasks which can be found in common mobile interaction use-cases. In a repeated-measures design, 29 participants interacted with the prototypes in a car-following task within a driving simulator environment. Task completion, driving performance and eye gaze have been analysed. We found that the slider widget used in the filtering task was too demanding and led to poor performance, while kinetic scrolling generated a comparable amount of visual distraction despite it requiring a lower degree of finger pointing accuracy. We discuss how to improve continuous list browsing in a dual-task context. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  2. Eyes Wide Shopped: Shopping Situations Trigger Arousal in Impulsive Buyers

    PubMed Central

    Serfas, Benjamin G.; Büttner, Oliver B.; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures. PMID:25489955

  3. Driving with homonymous visual field loss: a review of the literature

    PubMed Central

    Bowers, Alex R.

    2016-01-01

    Driving is an important rehabilitation goal for patients with homonymous field defects (HFDs); however, whether or not people with HFDs should be permitted to drive is not clear. Over the last 15 years there has been a marked increase in the number of studies evaluating the effects of HFDs on driving performance. This review of the literature provides a much-needed summary for practitioners and researchers, addressing the following topics: regulations pertaining to driving with HFDs, self-reported driving difficulties, pass rates in on-road tests, the effects of HFDs on lane position and steering stability, the effects of HFDs on scanning and detection of potential hazards, screening for potential fitness to drive, evaluating practical fitness to drive, and the efficacy of interventions to improve driving of persons with HFDs. Although there is clear evidence from on-road studies that some people with HFDs may be rated as safe to drive, others are reported to have significant deficits in skills important for safe driving including taking a lane position too close to one side of the travel lane, unstable steering and inadequate viewing (scanning) behaviors. Driving simulator studies have provided strong evidence of a wide range in compensatory scanning abilities and detection performance, despite similar amounts of visual field loss. Conventional measurements of visual field extent (in which eye movements are not permitted) do not measure such compensatory abilities and are not predictive of on-road driving performance; thus, there is a need to develop better tests to screen for visual fitness to drive of people with HFDs. We are not yet at a point where we can predict which HFD patient is likely to be a safe driver. Therefore, it seems only fair to provide an opportunity for individualized assessments of practical fitness to drive either on the road and/or in a driving simulator. PMID:27535208

  4. Driving with homonymous visual field loss: a review of the literature.

    PubMed

    Bowers, Alex R

    2016-09-01

    Driving is an important rehabilitation goal for patients with homonymous field defects (HFDs); however, whether or not people with HFDs should be permitted to drive is not clear. Over the last 15 years, there has been a marked increase in the number of studies evaluating the effects of HFDs on driving performance. This review of the literature provides a much-needed summary for practitioners and researchers, addressing the following topics: regulations pertaining to driving with HFDs, self-reported driving difficulties, pass rates in on-road tests, the effects of HFDs on lane position and steering stability, the effects of HFDs on scanning and detection of potential hazards, screening for potential fitness to drive, evaluating practical fitness to drive and the efficacy of interventions to improve driving of persons with HFDs. Although there is clear evidence from on-road studies that some people with HFDs may be rated as safe to drive, others are reported to have significant deficits in skills important for safe driving, including taking a lane position too close to one side of the travel lane, unstable steering and inadequate viewing (scanning) behaviour. Driving simulator studies have provided strong evidence of a wide range in compensatory scanning abilities and detection performance, despite similar amounts of visual field loss. Conventional measurements of visual field extent (in which eye movements are not permitted) do not measure such compensatory abilities and are not predictive of on-road driving performance. Thus, there is a need to develop better tests to screen people with HFDs for visual fitness to drive. We are not yet at a point where we can predict which HFD patient is likely to be a safe driver. Therefore, it seems only fair to provide an opportunity for individualised assessments of practical fitness to drive either on the road and/or in a driving simulator. © 2016 Optometry Australia.

  5. Objective Assessment of Activity Limitation in Glaucoma with Smartphone Virtual Reality Goggles: A Pilot Study.

    PubMed

    Goh, Rachel L Z; Kong, Yu Xiang George; McAlinden, Colm; Liu, John; Crowston, Jonathan G; Skalicky, Simon E

    2018-01-01

    To evaluate the use of smartphone-based virtual reality to objectively assess activity limitation in glaucoma. Cross-sectional study of 93 patients (54 mild, 22 moderate, 17 severe glaucoma). Sociodemographics, visual parameters, Glaucoma Activity Limitation-9 and Visual Function Questionnaire - Utility Index (VFQ-UI) were collected. Mean age was 67.4 ± 13.2 years; 52.7% were male; 65.6% were driving. A smartphone placed inside virtual reality goggles was used to administer the Virtual Reality Glaucoma Visual Function Test (VR-GVFT) to participants, consisting of three parts: stationary, moving ball, driving. Rasch analysis and classical validity tests were conducted to assess performance of VR-GVFT. Twenty-four of 28 stationary test items showed acceptable fit to the Rasch model (person separation 3.02, targeting 0). Eleven of 12 moving ball test items showed acceptable fit (person separation 3.05, targeting 0). No driving test items showed acceptable fit. Stationary test person scores showed good criterion validity, differentiating between glaucoma severity groups ( P = 0.014); modest convergence validity, with mild to moderate correlation with VFQ-UI, better eye (BE) mean deviation, BE pattern deviation, BE central scotoma, worse eye (WE) visual acuity, and contrast sensitivity (CS) in both eyes ( R = 0.243-0.381); and suboptimal divergent validity. Multivariate analysis showed that lower WE CS ( P = 0.044) and greater age ( P = 0.009) were associated with worse stationary test person scores. Smartphone-based virtual reality may be a portable objective simulation test of activity limitation related to glaucomatous visual loss. The use of simulated virtual environments could help better understand the activity limitations that affect patients with glaucoma.

  6. Objective Assessment of Activity Limitation in Glaucoma with Smartphone Virtual Reality Goggles: A Pilot Study

    PubMed Central

    Goh, Rachel L. Z.; McAlinden, Colm; Liu, John; Crowston, Jonathan G.; Skalicky, Simon E.

    2018-01-01

    Purpose To evaluate the use of smartphone-based virtual reality to objectively assess activity limitation in glaucoma. Methods Cross-sectional study of 93 patients (54 mild, 22 moderate, 17 severe glaucoma). Sociodemographics, visual parameters, Glaucoma Activity Limitation-9 and Visual Function Questionnaire – Utility Index (VFQ-UI) were collected. Mean age was 67.4 ± 13.2 years; 52.7% were male; 65.6% were driving. A smartphone placed inside virtual reality goggles was used to administer the Virtual Reality Glaucoma Visual Function Test (VR-GVFT) to participants, consisting of three parts: stationary, moving ball, driving. Rasch analysis and classical validity tests were conducted to assess performance of VR-GVFT. Results Twenty-four of 28 stationary test items showed acceptable fit to the Rasch model (person separation 3.02, targeting 0). Eleven of 12 moving ball test items showed acceptable fit (person separation 3.05, targeting 0). No driving test items showed acceptable fit. Stationary test person scores showed good criterion validity, differentiating between glaucoma severity groups (P = 0.014); modest convergence validity, with mild to moderate correlation with VFQ-UI, better eye (BE) mean deviation, BE pattern deviation, BE central scotoma, worse eye (WE) visual acuity, and contrast sensitivity (CS) in both eyes (R = 0.243–0.381); and suboptimal divergent validity. Multivariate analysis showed that lower WE CS (P = 0.044) and greater age (P = 0.009) were associated with worse stationary test person scores. Conclusions Smartphone-based virtual reality may be a portable objective simulation test of activity limitation related to glaucomatous visual loss. Translational Relevance The use of simulated virtual environments could help better understand the activity limitations that affect patients with glaucoma. PMID:29372112

  7. Strabismus and the Oculomotor System: Insights from Macaque Models

    PubMed Central

    Das, Vallabh E.

    2017-01-01

    Disrupting binocular vision in infancy leads to strabismus and oftentimes to a variety of associated visual sensory deficits and oculomotor abnormalities. Investigation of this disorder has been aided by the development of various animal models, each of which has advantages and disadvantages. In comparison to studies of binocular visual responses in cortical structures, investigations of neural oculomotor structures that mediate the misalignment and abnormalities of eye movements have been more recent, and these studies have shown that different brain areas are intimately involved in driving several aspects of the strabismic condition, including horizontal misalignment, dissociated deviations, A and V patterns of strabismus, disconjugate eye movements, nystagmus, and fixation switch. The responses of cells in visual and oculomotor areas that potentially drive the sensory deficits and also eye alignment and eye movement abnormalities follow a general theme of disrupted calibration, lower sensitivity, and poorer specificity compared with the normally developed visual oculomotor system. PMID:28532347

  8. Opportunity's View After Drive on Sol 1806 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11816 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11816

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo, full-circle view of the rover's surroundings just after driving 60.86 meters (200 feet) on the 1,806th Martian day, or sol, of Opportunity's surface mission (Feb. 21, 2009). North is at the center; south at both ends.

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    Tracks from the drive extend northward across dark-toned sand ripples and light-toned patches of exposed bedrock in the Meridiani Planum region of Mars. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    Engineers designed the Sol 1806 drive to be driven backwards as a strategy to redistribute lubricant in the rovers wheels. The right-front wheel had been showing signs of increased friction.

    The rover's position after the Sol 1806 drive was about 2 kilometer (1.2 miles) south southwest of Victoria Crater. Cumulative odometry was 14.74 kilometers (9.16 miles) since landing in January 2004, including 2.96 kilometers (1.84 miles) since climbing out of Victoria Crater on the west side of the crater on Sol 1634 (August 28, 2008).

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  9. Opportunity's View After Long Drive on Sol 1770 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11791 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11791

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo, full-circle view of the rover's surroundings just after driving 104 meters (341 feet) on the 1,770th Martian day, or sol, of Opportunity's surface mission (January 15, 2009).

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    Tracks from the drive extend northward across dark-toned sand ripples and light-toned patches of exposed bedrock in the Meridiani Planum region of Mars. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    Prior to the Sol 1770 drive, Opportunity had driven less than a meter since Sol 1713 (November 17, 2008), while it used the tools on its robotic arm first to examine a meteorite called 'Santorini' during weeks of restricted communication while the sun was nearly in line between Mars and Earth, then to examine bedrock and soil targets near Santorini.

    The rover's position after the Sol 1770 drive was about 1.1 kilometer (two-thirds of a mile) south southwest of Victoria Crater. Cumulative odometry was 13.72 kilometers (8.53 miles) since landing in January 2004, including 1.94 kilometers (1.21 miles) since climbing out of Victoria Crater on the west side of the crater on Sol 1634 (August 28, 2008).

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  10. Eye Movement Patterns for Novice Teen Drivers Does 6 Months of Driving Experience Make a Difference?

    PubMed Central

    Olsen, Erik C. B.; Lee, Suzanne E.; Simons-Morton, Bruce G.

    2009-01-01

    Attention to the road is essential to safe driving, but the development of appropriate eye glance scanning behaviors may require substantial driving experience. Novice teen drivers may focus almost exclusively on the road ahead rather than scanning the mirrors, and when performing secondary tasks, they may spend more time with eyes on the task than on the road. This paper examines the extent to which the scanning of novice teens improves with experience. For this study, 18 novice teen (younger than 17.5 years old) and 18 experienced adult drivers performed a set of in-vehicle tasks and a baseline driving segment on a test track, the teens within 4 weeks of licensure and then again 6 months later. This paper addresses the following questions: Did teen eye glance performance improve from initial assessment? Did teens and adults still differ after 6 months? Results for some tasks showed that rearview and left mirror–window (LM-W) glances improved for teens from initial testing to the 6-month follow-up and that some differences between teens and adults at initial testing were no longer significant at the 6-month follow-up, suggesting significant learning effects. The frequency of rearview and LM-W glances during secondary tasks improved among teens at the 6-month follow-up, but teens still had significantly fewer glances to mirrors than did adults when engaged in a secondary task. PMID:19763225

  11. Driving habits in older patients with central vision loss.

    PubMed

    Sengupta, Sabyasachi; van Landingham, Suzanne W; Solomon, Sharon D; Do, Diana V; Friedman, David S; Ramulu, Pradeep Y

    2014-03-01

    To determine if central visual loss is associated with driving cessation, driving restriction, or other-driver preference. Cross-sectional study. Sixty-four subjects with bilateral visual loss (<20/32 in better eye) or severe unilateral visual loss (<20/200) from age-related macular degeneration (AMD) and 58 normally sighted controls between 60 and 80 years of age. Participants self-reported driving habits. Other-driver preference was defined as preferring that another drive when there is more than 1 driver in the car. Subjects reporting 2 or more driving limitations were considered to have restricted their driving. Self-reported driving cessation, other-driver preference, and driving restriction. Age-related macular degeneration subjects were older (74.7 vs. 69.7 years), had worse visual acuity (VA; mean better-eye VA, 0.43 vs. 0.08 logarithm of minimum angle of resolution [logMAR]) and contrast sensitivity (CS; 1.4 vs. 1.9 log units of CS [logCS]), and were more likely to be white when compared with controls (P<0.001 for all). Drivers with AMD-related vision loss were more likely to avoid driving over longer distances, beyond 1 hour, at night, and in unfamiliar conditions (P < 0.05 for all). In multivariate models, driving cessation was associated with worse better-eye VA (odds ratio [OR], 1.5 per 1-line decrement in VA; P<0.001) and worse binocular CS (OR, 1.36 per 0.1 logCS increment; P = 0.005); however, AMD group status was not associated with driving cessation (OR, 1.9; P = 0.35). Factors predicting driving restriction were AMD (OR, 9.0; P = 0.004), worse vision (OR, 2.5 per line of VA loss; P<0.001), lower CS (OR, 2.2 per 0.1-logCS increment; P<0.001), and female gender (OR, 27.9; P = 0.002). Other-driver preference was more common with worse vision (OR, 1.6 per 0.1-logMAR increment; P = 0.003), female gender (OR, 4.5; P = 0.02), and being married (OR, 3.8; P = 0.04). Most patients with AMD-related central vision loss continue to drive, but demonstrate significant driving restrictions, especially with more severe VA and CS loss. Future work should determine which driving adaptations the visually impaired best balance safety and independence. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  12. SmartEye and Polhemus data for vestibulo-ocular reflex and optokinetic reflex model.

    PubMed

    Le, Anh Son; Aoki, Hirofumi

    2018-06-01

    In this data article, this dataset included raw data of head and eye movement that collected by Polhemus (Polhemus Inc) and SmartEye (Smart Eye AB) equipment. Subjects who have driver license participated in this experiment. The experiment was conducted with a driving simulator that was controlled by CarSim (Mechanical simulation Co., Anna Arbor, MI) with the vehicle motion. This data set not only contained the eye and head movement but also had eye gaze, pupil diameter, saccades, and so on. It can be used for the parameter identification of the vestibulor-ocular reflex (VOR) model, simulation eye movement, as well as running other analysis related to eye movement.

  13. Assessing video games to improve driving skills: a literature review and observational study.

    PubMed

    Sue, Damian; Ray, Pradeep; Talaei-Khoei, Amir; Jonnagaddala, Jitendra; Vichitvanichphong, Suchada

    2014-08-07

    For individuals, especially older adults, playing video games is a promising tool for improving their driving skills. The ease of use, wide availability, and interactivity of gaming consoles make them an attractive simulation tool. The objective of this study was to look at the feasibility and effects of installing video game consoles in the homes of individuals looking to improve their driving skills. A systematic literature review was conducted to assess the effect of playing video games on improving driving skills. An observatory study was performed to evaluate the feasibility of using an Xbox 360 Kinect console for improving driving skills. Twenty-nine articles, which discuss the implementation of video games in improving driving skills were found in literature. On our study, it was found the Xbox 360 with Kinect is capable of improving physical and mental activities. Xbox Video games were introduced to engage players in physical, visual and cognitive activities including endurance, postural sway, reaction time, eyesight, eye movement, attention and concentration, difficulties with orientation, and semantic fluency. However, manual dexterity, visuo-spatial perception and binocular vision could not be addressed by these games. It was observed that Xbox Kinect (by incorporating Kinect sensor facilities) combines physical, visual and cognitive engagement of players. These results were consistent with those from the literature review. From the research that has been carried out, we can conclude that video game consoles are a viable solution for improving user's physical and mental state. In future we propose to carry a thorough evaluation of the effects of video games on driving skills in elderly people.

  14. Problems with vision associated with limitations or avoidance of driving in older populations.

    PubMed

    Satariano, William A; MacLeod, Kara E; Cohn, Theodore E; Ragland, David R

    2004-09-01

    This report examines the role of (a) disease processes affecting vision, (b) reported troubles with vision, (c) physical symptoms affecting the eyes, and (d) objective measures in reported driving limitation due to problems with eyesight among older drivers. Data for this study (N = 1,840) were obtained from participants in a community-based study of aging and physical performance in people age 55 or older in the city of Sonoma, California. Each of 16 visual conditions was assessed for impact on reported driving limitation due to eyesight by calculating a "risk" ratio. Then, prevalence of the condition was combined with the ratio to generate an attributable risk for that condition for vision-related limitations in driving. Each condition was significantly associated with reported limitations in driving due to eyesight. "Avoiding physical activity due to vision" (ratio = 3.4) and "trouble seeing steps up/down stairs" (ratio = 2.9) had the strongest association. However, "glasses/contacts required for driving" and "trouble with glare from sun/lights" had the highest attributable risks (35.8 and 29.4). The risk ratio is relevant for evaluating individuals; the attributable risk is relevant to planning countermeasures in populations. Addressing specific problems related to vision should substantially reduce driving limitations due to eyesight.

  15. An analysis of the suitability of a low-cost eye tracker for assessing the cognitive load of drivers.

    PubMed

    Čegovnik, Tomaž; Stojmenova, Kristina; Jakus, Grega; Sodnik, Jaka

    2018-04-01

    This paper presents a driving simulator study in which we investigated whether the Eye Tribe eye tracker (ET) is capable of assessing changes in the cognitive load of drivers through oculography and pupillometry. In the study, participants were asked to drive a simulated vehicle and simultaneously perform a set of secondary tasks with different cognitive complexity levels. We measured changes in eye properties, such as the pupil size, blink rate and fixation time. We also performed a measurement with a Detection Response Task (DRT) to validate the results and to prove a steady increase of cognitive load with increasing secondary task difficulty. The results showed that the ET precisely recognizes an increasing pupil diameter with increasing secondary task difficulty. In addition, the ET shows increasing blink rates, decreasing fixation time and narrowing of the attention field with increasing secondary task difficulty. The results were validated with the DRT method and the secondary task performance. We conclude that the Eye Tribe ET is a suitable device for assessing a driver's cognitive load. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Predicting Risk of Motor Vehicle Collisions in Patients with Glaucoma: A Longitudinal Study.

    PubMed

    Gracitelli, Carolina P B; Tatham, Andrew J; Boer, Erwin R; Abe, Ricardo Y; Diniz-Filho, Alberto; Rosen, Peter N; Medeiros, Felipe A

    2015-01-01

    To evaluate the ability of longitudinal Useful Field of View (UFOV) and simulated driving measurements to predict future occurrence of motor vehicle collision (MVC) in drivers with glaucoma. Prospective observational cohort study. 117 drivers with glaucoma followed for an average of 2.1 ± 0.5 years. All subjects had standard automated perimetry (SAP), UFOV, driving simulator, and cognitive assessment obtained at baseline and every 6 months during follow-up. The driving simulator evaluated reaction times to high and low contrast peripheral divided attention stimuli presented while negotiating a winding country road, with central driving task performance assessed as "curve coherence". Drivers with MVC during follow-up were identified from Department of Motor Vehicle records. Survival models were used to evaluate the ability of driving simulator and UFOV to predict MVC over time, adjusting for potential confounding factors. Mean age at baseline was 64.5 ± 12.6 years. 11 of 117 (9.4%) drivers had a MVC during follow-up. In the multivariable models, low contrast reaction time was significantly predictive of MVC, with a hazard ratio (HR) of 2.19 per 1 SD slower reaction time (95% CI, 1.30 to 3.69; P = 0.003). UFOV divided attention was also significantly predictive of MVC with a HR of 1.98 per 1 SD worse (95% CI, 1.10 to 3.57; P = 0.022). Global SAP visual field indices in the better or worse eye were not predictive of MVC. The longitudinal model including driving simulator performance was a better predictor of MVC compared to UFOV (R2 = 0.41 vs R2 = 0.18). Longitudinal divided attention metrics on the UFOV test and during simulated driving were significantly predictive of risk of MVC in glaucoma patients. These findings may help improve the understanding of factors associated with driving impairment related to glaucoma.

  17. Attentional Differences in a Driving Hazard Perception Task in Adults with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Sheppard, Elizabeth; van Loon, Editha; Underwood, Geoffrey; Ropar, Danielle

    2017-01-01

    The current study explored attentional processing of social and non-social stimuli in ASD within the context of a driving hazard perception task. Participants watched videos of road scenes and detected hazards while their eye movements were recorded. Although individuals with ASD demonstrated relatively good detection of driving hazards, they were…

  18. Visual and non-visual motion information processing during pursuit eye tracking in schizophrenia and bipolar disorder.

    PubMed

    Trillenberg, Peter; Sprenger, Andreas; Talamo, Silke; Herold, Kirsten; Helmchen, Christoph; Verleger, Rolf; Lencer, Rebekka

    2017-04-01

    Despite many reports on visual processing deficits in psychotic disorders, studies are needed on the integration of visual and non-visual components of eye movement control to improve the understanding of sensorimotor information processing in these disorders. Non-visual inputs to eye movement control include prediction of future target velocity from extrapolation of past visual target movement and anticipation of future target movements. It is unclear whether non-visual input is impaired in patients with schizophrenia. We recorded smooth pursuit eye movements in 21 patients with schizophrenia spectrum disorder, 22 patients with bipolar disorder, and 24 controls. In a foveo-fugal ramp task, the target was either continuously visible or was blanked during movement. We determined peak gain (measuring overall performance), initial eye acceleration (measuring visually driven pursuit), deceleration after target extinction (measuring prediction), eye velocity drifts before onset of target visibility (measuring anticipation), and residual gain during blanking intervals (measuring anticipation and prediction). In both patient groups, initial eye acceleration was decreased and the ability to adjust eye acceleration to increasing target acceleration was impaired. In contrast, neither deceleration nor eye drift velocity was reduced in patients, implying unimpaired non-visual contributions to pursuit drive. Disturbances of eye movement control in psychotic disorders appear to be a consequence of deficits in sensorimotor transformation rather than a pure failure in adding cognitive contributions to pursuit drive in higher-order cortical circuits. More generally, this deficit might reflect a fundamental imbalance between processing external input and acting according to internal preferences.

  19. Meiotic drive impacts expression and evolution of x-linked genes in stalk-eyed flies.

    PubMed

    Reinhardt, Josephine A; Brand, Cara L; Paczolt, Kimberly A; Johns, Philip M; Baker, Richard H; Wilkinson, Gerald S

    2014-01-01

    Although sex chromosome meiotic drive has been observed in a variety of species for over 50 years, the genes causing drive are only known in a few cases, and none of these cases cause distorted sex-ratios in nature. In stalk-eyed flies (Teleopsis dalmanni), driving X chromosomes are commonly found at frequencies approaching 30% in the wild, but the genetic basis of drive has remained elusive due to reduced recombination between driving and non-driving X chromosomes. Here, we used RNAseq to identify transcripts that are differentially expressed between males carrying either a driving X (XSR) or a standard X chromosome (XST), and found hundreds of these, the majority of which are X-linked. Drive-associated transcripts show increased levels of sequence divergence (dN/dS) compared to a control set, and are predominantly expressed either in testes or in the gonads of both sexes. Finally, we confirmed that XSR and XST are highly divergent by estimating sequence differentiation between the RNAseq pools. We found that X-linked transcripts were often strongly differentiated (whereas most autosomal transcripts were not), supporting the presence of a relatively large region of recombination suppression on XSR presumably caused by one or more inversions. We have identified a group of genes that are good candidates for further study into the causes and consequences of sex-chromosome drive, and demonstrated that meiotic drive has had a profound effect on sequence evolution and gene expression of X-linked genes in this species.

  20. New Record Five-Wheel Drive, Spirit's Sol 1856 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11962 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11962

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,856th Martian day, or sol, of Spirit's surface mission (March 23, 2009). The center of the view is toward the west-southwest.

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The rover had driven 25.82 meters (84.7 feet) west-northwestward earlier on Sol 1856. This is the longest drive on Mars so far by a rover using only five wheels. Spirit lost the use of its right-front wheel in March 2006. Before Sol 1856, the farthest Spirit had covered in a single sol's five-wheel drive was 24.83 meters (81.5 feet), on Sol 1363 (Nov. 3, 2007).

    The Sol 1856 drive made progress on a route planned for taking Spirit around the western side of the low plateau called 'Home Plate.' A portion of the northwestern edge of Home Plate is prominent in the left quarter of this image, toward the south.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  1. Simple gaze-contingent cues guide eye movements in a realistic driving simulator

    NASA Astrophysics Data System (ADS)

    Pomarjanschi, Laura; Dorr, Michael; Bex, Peter J.; Barth, Erhardt

    2013-03-01

    Looking at the right place at the right time is a critical component of driving skill. Therefore, gaze guidance has the potential to become a valuable driving assistance system. In previous work, we have already shown that complex gaze-contingent stimuli can guide attention and reduce the number of accidents in a simple driving simulator. We here set out to investigate whether cues that are simple enough to be implemented in a real car can also capture gaze during a more realistic driving task in a high-fidelity driving simulator. We used a state-of-the-art, wide-field-of-view driving simulator with an integrated eye tracker. Gaze-contingent warnings were implemented using two arrays of light-emitting diodes horizontally fitted below and above the simulated windshield. Thirteen volunteering subjects drove along predetermined routes in a simulated environment popu­ lated with autonomous traffic. Warnings were triggered during the approach to half of the intersections, cueing either towards the right or to the left. The remaining intersections were not cued, and served as controls. The analysis of the recorded gaze data revealed that the gaze-contingent cues did indeed have a gaze guiding effect, triggering a significant shift in gaze position towards the highlighted direction. This gaze shift was not accompanied by changes in driving behaviour, suggesting that the cues do not interfere with the driving task itself.

  2. Linking mind wandering tendency to risky driving in young male drivers.

    PubMed

    Albert, Derek A; Ouimet, Marie Claude; Jarret, Julien; Cloutier, Marie-Soleil; Paquette, Martin; Badeau, Nancy; Brown, Thomas G

    2018-02-01

    Risky driving is a significant contributor to road traffic crashes, especially in young drivers. Transient mind wandering states, an internal form of distraction, are associated with faster driving, reduced headway distance, slower response times, reduced driver vigilance, and increased crash risk. It is unclear whether a trait tendency to mind wander predicts risky driving, however. Mind wandering is also associated with poor executive control, but whether this capacity moderates the putative link between mind wandering tendency and risky driving is uncertain. The present study tested whether mind wandering tendency predicts risky driving behaviour in young male drivers aged 18-21 (N=30) and whether this relationship is mediated by driver vigilance and moderated by executive control capacity. Mind wandering was measured with the Sustained Attention to Response Task (SART) and the Daydreaming Frequency Scale (DDFS). Risky driving was assessed by mean speed in a driving simulator and driver vigilance was quantified by horizontal eye movements measured with eye tracking. Results showed that greater mind wandering tendency based on SART performance significantly predicts faster mean speed, confirming the main hypothesis. Neither driver vigilance mediated nor executive control capacity moderated this relationship as hypothesized. These findings speak to the complexity of individual differences in mind wandering. Overall, mind wandering tendency is a significant marker of risky driving in young drivers, which could guide the development of targeted interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Wind-Sculpted Vicinity After Opportunity's Sol 1797 Drive (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11820 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11820

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo, full-circle view of the rover's surroundings just after driving 111 meters (364 feet) on the 1,797th Martian day, or sol, of Opportunity's surface mission (Feb. 12, 2009). North is at the center; south at both ends.

    This view is the right-eye member of a stereo pair presented as a cylindrical-perspective projection with geometric seam correction.

    Tracks from the drive recede northward across dark-toned sand ripples in the Meridiani Planum region of Mars. Patches of lighter-toned bedrock are visible on the left and right sides of the image. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  4. Driver distraction : eye glance analysis and conversation workload.

    DOT National Transportation Integrated Search

    2015-11-01

    The objective of this project was to assess the risk of performing a secondary task while driving a commercial : motor vehicle (CMV). The risk of conversation workload while driving a CMV was also assessed. Conversation : workload is a proxy for cogn...

  5. Eye Absence Does Not Regulate Planarian Stem Cells during Eye Regeneration.

    PubMed

    LoCascio, Samuel A; Lapan, Sylvain W; Reddien, Peter W

    2017-02-27

    Dividing cells called neoblasts contain pluripotent stem cells and drive planarian flatworm regeneration from diverse injuries. A long-standing question is whether neoblasts directly sense and respond to the identity of missing tissues during regeneration. We used the eye to investigate this question. Surprisingly, eye removal was neither sufficient nor necessary for neoblasts to increase eye progenitor production. Neoblasts normally increase eye progenitor production following decapitation, facilitating regeneration. Eye removal alone, however, did not induce this response. Eye regeneration following eye-specific resection resulted from homeostatic rates of eye progenitor production and less cell death in the regenerating eye. Conversely, large head injuries that left eyes intact increased eye progenitor production. Large injuries also non-specifically increased progenitor production for multiple uninjured tissues. We propose a model for eye regeneration in which eye tissue production by planarian stem cells is not directly regulated by the absence of the eye itself. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Spatial scale and distribution of neurovascular signals underlying decoding of orientation and eye of origin from fMRI data

    PubMed Central

    Harrison, Charlotte; Jackson, Jade; Oh, Seung-Mock; Zeringyte, Vaida

    2016-01-01

    Multivariate pattern analysis of functional magnetic resonance imaging (fMRI) data is widely used, yet the spatial scales and origin of neurovascular signals underlying such analyses remain unclear. We compared decoding performance for stimulus orientation and eye of origin from fMRI measurements in human visual cortex with predictions based on the columnar organization of each feature and estimated the spatial scales of patterns driving decoding. Both orientation and eye of origin could be decoded significantly above chance in early visual areas (V1–V3). Contrary to predictions based on a columnar origin of response biases, decoding performance for eye of origin in V2 and V3 was not significantly lower than that in V1, nor did decoding performance for orientation and eye of origin differ significantly. Instead, response biases for both features showed large-scale organization, evident as a radial bias for orientation, and a nasotemporal bias for eye preference. To determine whether these patterns could drive classification, we quantified the effect on classification performance of binning voxels according to visual field position. Consistent with large-scale biases driving classification, binning by polar angle yielded significantly better decoding performance for orientation than random binning in V1–V3. Similarly, binning by hemifield significantly improved decoding performance for eye of origin. Patterns of orientation and eye preference bias in V2 and V3 showed a substantial degree of spatial correlation with the corresponding patterns in V1, suggesting that response biases in these areas originate in V1. Together, these findings indicate that multivariate classification results need not reflect the underlying columnar organization of neuronal response selectivities in early visual areas. NEW & NOTEWORTHY Large-scale response biases can account for decoding of orientation and eye of origin in human early visual areas V1–V3. For eye of origin this pattern is a nasotemporal bias; for orientation it is a radial bias. Differences in decoding performance across areas and stimulus features are not well predicted by differences in columnar-scale organization of each feature. Large-scale biases in extrastriate areas are spatially correlated with those in V1, suggesting biases originate in primary visual cortex. PMID:27903637

  7. Evaluating the speed of visual recovery following thin-flap LASIK with a femtosecond laser.

    PubMed

    Durrie, Daniel S; Brinton, Jason P; Avila, Michele R; Stahl, Erin D

    2012-09-01

    To investigate the speed of visual recovery following myopic thin-flap LASIK with a femtosecond laser. This pilot study prospectively evaluated 20 eyes from 10 patients who underwent bilateral simultaneous LASIK with the Femto LDV Crystal Line femtosecond laser (Ziemer Ophthalmic Systems AG) used to create a circular flap of 9.0-mm diameter and 110-μm thickness followed by photoablation with the Allegretto Wave Eye-Q (WaveLight AG) excimer laser. Binocular and monocular uncorrected distance visual acuity (UDVA), monocular contrast sensitivity, and a patient questionnaire were evaluated during the first hours, 1 day, and 1 month postoperatively. For monocular UDVA, 100% of eyes were 20/40 at 1 hour and 100% were 20/25 at 4 hours. For binocular UDVA, all patients achieved 20/32 by 30 minutes and 20/20 by 4 hours. Low frequency contrast sensitivity returned to preoperative baseline by 1 hour (P=.73), and showed a statistically significant improvement over baseline by 4 hours (P=.01). High frequency monocular contrast sensitivity returned to preoperative baseline by 4 hours (P=.48), and showed a statistically significant improvement by 1 month (P=.04). At 2 and 4 hours, 50% and 100% of patients, respectively, indicated that they would feel comfortable driving. Visual recovery after thin-flap femtosecond LASIK is rapid, occurring within the first few hours after surgery. Copyright 2012, SLACK Incorporated.

  8. A Causal Role for the Cortical Frontal Eye Fields in Microsaccade Deployment

    PubMed Central

    Dash, Suryadeep; Lomber, Stephen G.

    2016-01-01

    Microsaccades aid vision by helping to strategically sample visual scenes. Despite the importance of these small eye movements, no cortical area has ever been implicated in their generation. Here, we used unilateral and bilateral reversible inactivation of the frontal eye fields (FEF) to identify a cortical drive for microsaccades. Unexpectedly, FEF inactivation altered microsaccade metrics and kinematics. Such inactivation also impaired microsaccade deployment following peripheral cue onset, regardless of cue side or inactivation configuration. Our results demonstrate that the FEF provides critical top-down drive for microsaccade generation, particularly during the recovery of microsaccades after disruption by sensory transients. Our results constitute the first direct evidence, to our knowledge, for the contribution of any cortical area to microsaccade generation, and they provide a possible substrate for how cognitive processes can influence the strategic deployment of microsaccades. PMID:27509130

  9. A Causal Role for the Cortical Frontal Eye Fields in Microsaccade Deployment.

    PubMed

    Peel, Tyler R; Hafed, Ziad M; Dash, Suryadeep; Lomber, Stephen G; Corneil, Brian D

    2016-08-01

    Microsaccades aid vision by helping to strategically sample visual scenes. Despite the importance of these small eye movements, no cortical area has ever been implicated in their generation. Here, we used unilateral and bilateral reversible inactivation of the frontal eye fields (FEF) to identify a cortical drive for microsaccades. Unexpectedly, FEF inactivation altered microsaccade metrics and kinematics. Such inactivation also impaired microsaccade deployment following peripheral cue onset, regardless of cue side or inactivation configuration. Our results demonstrate that the FEF provides critical top-down drive for microsaccade generation, particularly during the recovery of microsaccades after disruption by sensory transients. Our results constitute the first direct evidence, to our knowledge, for the contribution of any cortical area to microsaccade generation, and they provide a possible substrate for how cognitive processes can influence the strategic deployment of microsaccades.

  10. Assessing Video Games to Improve Driving Skills: A Literature Review and Observational Study

    PubMed Central

    Sue, Damian; Vichitvanichphong, Suchada

    2014-01-01

    Background For individuals, especially older adults, playing video games is a promising tool for improving their driving skills. The ease of use, wide availability, and interactivity of gaming consoles make them an attractive simulation tool. Objective The objective of this study was to look at the feasibility and effects of installing video game consoles in the homes of individuals looking to improve their driving skills. Methods A systematic literature review was conducted to assess the effect of playing video games on improving driving skills. An observatory study was performed to evaluate the feasibility of using an Xbox 360 Kinect console for improving driving skills. Results Twenty–nine articles, which discuss the implementation of video games in improving driving skills were found in literature. On our study, it was found the Xbox 360 with Kinect is capable of improving physical and mental activities. Xbox Video games were introduced to engage players in physical, visual and cognitive activities including endurance, postural sway, reaction time, eyesight, eye movement, attention and concentration, difficulties with orientation, and semantic fluency. However, manual dexterity, visuo-spatial perception and binocular vision could not be addressed by these games. It was observed that Xbox Kinect (by incorporating Kinect sensor facilities) combines physical, visual and cognitive engagement of players. These results were consistent with those from the literature review. Conclusions From the research that has been carried out, we can conclude that video game consoles are a viable solution for improving user’s physical and mental state. In future we propose to carry a thorough evaluation of the effects of video games on driving skills in elderly people. PMID:25654355

  11. Multipulse control of saccadic eye movements

    NASA Technical Reports Server (NTRS)

    Lehman, S. L.; Stark, L.

    1981-01-01

    We present three conclusions regarding the neural control of saccadic eye movements, resulting from comparisons between recorded movements and computer simulations. The controller signal to the muscles is probably a multipulse-step. This kind of signal drives the fastest model trajectories. Finally, multipulse signals explain differences between model and electrophysiological results.

  12. Keep Your Scanners Peeled: Gaze Behavior as a Measure of Automation Trust During Highly Automated Driving.

    PubMed

    Hergeth, Sebastian; Lorenz, Lutz; Vilimek, Roman; Krems, Josef F

    2016-05-01

    The feasibility of measuring drivers' automation trust via gaze behavior during highly automated driving was assessed with eye tracking and validated with self-reported automation trust in a driving simulator study. Earlier research from other domains indicates that drivers' automation trust might be inferred from gaze behavior, such as monitoring frequency. The gaze behavior and self-reported automation trust of 35 participants attending to a visually demanding non-driving-related task (NDRT) during highly automated driving was evaluated. The relationship between dispositional, situational, and learned automation trust with gaze behavior was compared. Overall, there was a consistent relationship between drivers' automation trust and gaze behavior. Participants reporting higher automation trust tended to monitor the automation less frequently. Further analyses revealed that higher automation trust was associated with lower monitoring frequency of the automation during NDRTs, and an increase in trust over the experimental session was connected with a decrease in monitoring frequency. We suggest that (a) the current results indicate a negative relationship between drivers' self-reported automation trust and monitoring frequency, (b) gaze behavior provides a more direct measure of automation trust than other behavioral measures, and (c) with further refinement, drivers' automation trust during highly automated driving might be inferred from gaze behavior. Potential applications of this research include the estimation of drivers' automation trust and reliance during highly automated driving. © 2016, Human Factors and Ergonomics Society.

  13. CULTURAL DISPLAY RULES DRIVE EYE GAZE DURING THINKING.

    PubMed

    McCarthy, Anjanie; Lee, Kang; Itakura, Shoji; Muir, Darwin W

    2006-11-01

    The authors measured the eye gaze displays of Canadian, Trinidadian, and Japanese participants as they answered questions for which they either knew, or had to derive, the answers. When they knew the answers, Trinidadians maintained the most eye contact, whereas Japanese maintained the least. When thinking about the answers to questions, Canadians and Trinidadians looked up, whereas Japanese looked down. Thus, for humans, gaze displays while thinking are at least in part culturally determined.

  14. A PC-based software test for measuring alcohol and drug effects in human subjects.

    PubMed

    Mills, K C; Parkman, K M; Spruill, S E

    1996-12-01

    A new software-based visual search and divided-attention test of cognitive performance was developed and evaluated in an alcohol dose-response study with 24 human subjects aged 21-62 years. The test used language-free, color, graphic displays to represent the visuospatial demands of driving. Cognitive demands were increased over previous hardware-based tests, and the motor skills required for the test involved minimal eye movements and eye-hand coordination. Repeated performance on the test was evaluated with a latin-square design by using a placebo and two alcohol doses, low (0.48 g/kg/LBM) and moderate (0.72 g/kg/LBM). The data on 7 females and 17 males yielded significant falling and rising impairment effects coincident with moderate rising and falling breath alcohol levels (mean peak BrALs = 0.045 g/dl and 0.079 g/dl). None of the subjects reported eye-strain or psychomotor fatigue as compared with previous tests. The high sensitivity/variance relative to use in basic and applied research, and worksite fitness-for-duty testing, was discussed. The most distinct advantage of a software-based test that operates on readily available PCs is that it can be widely distributed to researchers with a common reference to compare a variety of alcohol and drug effects.

  15. Effects of Age-Related Macular Degeneration on Driving Performance

    PubMed Central

    Wood, Joanne M.; Black, Alex A.; Mallon, Kerry; Kwan, Anthony S.; Owsley, Cynthia

    2018-01-01

    Purpose To explore differences in driving performance of older adults with age-related macular degeneration (AMD) and age-matched controls, and to identify the visual determinants of driving performance in this population. Methods Participants included 33 older drivers with AMD (mean age [M] = 76.6 ± 6.1 years; better eye Age-Related Eye Disease Study grades: early [61%] and intermediate [39%]) and 50 age-matched controls (M = 74.6 ± 5.0 years). Visual tests included visual acuity, contrast sensitivity, visual fields, and motion sensitivity. On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist (masked to drivers' visual status). Outcome measures included driving safety ratings (scale of 1–10, where higher values represented safer driving), types of driving behavior errors, locations at which errors were made, and number of critical errors (CE) requiring an instructor intervention. Results Drivers with AMD were rated as less safe than controls (4.8 vs. 6.2; P = 0.012); safety ratings were associated with AMD severity (early: 5.5 versus intermediate: 3.7), even after adjusting for age. Drivers with AMD had higher CE rates than controls (1.42 vs. 0.36, respectively; rate ratio 3.05, 95% confidence interval 1.47–6.36, P = 0.003) and exhibited more observation, lane keeping, and gap selection errors and made more errors at traffic light–controlled intersections (P < 0.05). Only motion sensitivity was significantly associated with driving safety in the AMD drivers (P = 0.005). Conclusions Drivers with early and intermediate AMD can exhibit impairments in their driving performance, particularly during complex driving situations; motion sensitivity was most strongly associated with driving performance. These findings have important implications for assessing the driving ability of older drivers with visual impairment. PMID:29340641

  16. On an efficient and effective intelligent transportation system (ITS) safety and traffic efficiency application with corresponding driver behavior

    NASA Astrophysics Data System (ADS)

    Ekedebe, Nnanna; Yu, Wei; Lu, Chao

    2015-06-01

    Driver distraction could result in safety compromises attributable to distractions from in-vehicle equipment usage [1]. The effective design of driver-vehicle interfaces (DVIs) and other human-machine interfaces (HMIs) together with their usability, and accessibility while driving become important [2]. Driving distractions can be classified as: visual distractions (any activity that takes your eyes away from the road), cognitive distraction (any activity that takes your mind away from the course of driving), and manual distractions (any activity that takes your hands away from the steering wheel [2]). Besides, multitasking during driving is a distractive activity that can increase the risks of vehicular accidents. To study the driver's behaviors on the safety of transportation system, using an in-vehicle driver notification application, we examined the effects of increasing driver distraction levels on the evaluation metrics of traffic efficiency and safety by using two types of driver models: young drivers (ages 16-25 years) and middle-age drivers (ages 30-45 years). Our evaluation data demonstrates that as a drivers distraction level is increased, less heed is given to change route directives from the in-vehicle on-board unit (OBU) using textual, visual, audio, and haptic notifications. Interestingly, middle-age drivers proved more effective/resilient in mitigating the negative effects of driver distraction over young drivers [2].

  17. Peer passenger influences on male adolescent drivers’ visual scanning behavior during simulated driving

    PubMed Central

    Pradhan, Anuj K.; Li, Kaigang; Bingham, C. Raymond; Simons-Morton, Bruce; Ouimet, Marie Claude; Shope, Jean T.

    2014-01-01

    Purpose There is a higher likelihood of crashes and fatalities when an adolescent drives with peer passengers, especially for male drivers and male passengers. Simulated driving of male adolescent drivers with male peer passengers was studied to examine passenger influences on distraction and inattention. Methods Male adolescents drove in a high-fidelity driving simulator with a male confederate who posed either as a risk-accepting or risk-averse passenger. Drivers’ eye-movements were recorded. The visual scanning behavior of the drivers was compared when driving alone versus when driving with a passenger, and when driving with a risk-accepting versus a risk-averse passenger. Results The visual scanning of a driver significantly narrowed horizontally and vertically when driving with a peer passenger. There were no significant differences in the times the drivers’ eyes were off the forward roadway when driving with a passenger versus when driving alone. Some significant correlations were found between personality characteristics and the outcome measures. Conclusions The presence of a male peer passenger was associated with a reduction in the visual scanning range of male adolescent drivers. This reduction could be a result of potential cognitive load imposed on the driver due to the presence of a passenger and the real or perceived normative influences or expectations from the passenger. Implications and contribution The presence of male peer passengers was associated with deficient visual scanning in male adolescent drivers. Such reduced scanning behavior is evident in drivers with high cognitive load. Further investigation of passenger influences on adolescent drivers should include examination of distraction and inattention aspects of passenger influence. PMID:24759440

  18. Female-specific down-regulation of tissue-PMN drives impaired Treg and amplified effector T cell responses in autoimmune dry eye disease1

    PubMed Central

    Gao, Yuan; Min, Kyungji; Zhang, Yibing; Su, John; Greenwood, Matthew; Gronert, Karsten

    2015-01-01

    Immune-driven dry eye disease primarily affects women; the cause for this sex-specific prevalence is unknown. PMN have distinct phenotypes that drive inflammation but also regulate lymphocytes and are the rate-limiting cell for generating anti-inflammatory lipoxin A4 (LXA4). Estrogen regulates the LXA4 circuit to induce delayed female-specific wound healing in the cornea. However, the role of PMN in dry eye disease remains unexplored. We discovered a LXA4-producing tissue-PMN population in the corneal limbus, lacrimal glands and cervical lymph nodes of healthy male and female mice. These tissue-PMN, unlike inflammatory-PMN, expressed a highly amplified LXA4 circuit and were sex-specifically regulated during immune-driven dry eye disease. Desiccating stress in females, unlike in males, triggered a remarkable decrease in lymph node PMN and LXA4 formation that remained depressed during dry eye disease. Depressed lymph node PMN and LXA4 in females correlated with an increase in T effector cells (TH1 and TH17), a decrease in regulatory T cells (Treg) and increased dry eye pathogenesis. Antibody depletion of tissue-PMN abrogated LXA4 formation in lymph nodes, caused a marked increase in TH1 and TH17 and decrease in Treg cells. To establish an immune regulatory role for PMN-derived LXA4 in dry eye females were treated with LXA4. LXA4 treatment markedly inhibited TH1 and TH17 and amplified Treg cells in draining lymph nodes, while reducing dry eye pathogenesis. These results identify female-specific regulation of LXA4-producing tissue-PMN as a potential key factor in aberrant T effector cell activation and initiation of immune-driven dry eye disease. PMID:26324767

  19. Eye Movements Behavior While Driving a Car: A Review

    DTIC Science & Technology

    1978-10-01

    should be filtered if only the relevant information input is to be inveatigated. -13- The analysis of eye movements bahavior should be consi- dered... volunt rvtlv switch hi , attent on From one eve to the other (e.q. LACK, 19"’). The accomodation of the eve at a greater distance in car Jriving

  20. MEMS scanner mirror based system for retina scanning and in eye projection

    NASA Astrophysics Data System (ADS)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Dallmann, Hans-Georg; Schelinski, Uwe; Grüger, Heinrich

    2015-02-01

    Many applications could benefit from miniaturized systems to scan blood vessels behind the retina in the human eye, so called "retina scanning". This reaches from access control to sophisticated security applications and medical devices. High volume systems for consumer applications require low cost and a user friendly operation. For example this includes no need for removal of glasses and self-adjustment, in turn guidance of focus and point of attraction by simultaneous projection for the user. A new system has been designed based on the well-known resonantly driven 2-d scanner mirror of Fraunhofer IPMS. A combined NIR and VIS laser system illuminates the eye through an eye piece designed for an operating distance allowing the use of glasses and granting sufficient field of view. This usability feature was considered to be more important than highest miniaturization. The modulated VIS laser facilitates the projection of an image directly onto the retina. The backscattered light from the continuous NIR laser contains the information of the blood vessels and is detected by a highly sensitive photo diode. A demonstrational setup has been realized including readout and driving electronics. The laser power was adjusted to an eye-secure level. Additional security features were integrated. Test measurements revealed promising results. In a first demonstration application the detection of biometric pattern of the blood vessels was evaluated for issues authentication in.

  1. Driving patterns in older adults with glaucoma.

    PubMed

    van Landingham, Suzanne W; Hochberg, Chad; Massof, Robert W; Chan, Emilie; Friedman, David S; Ramulu, Pradeep Y

    2013-02-21

    The ability to drive is important for ensuring quality of life for many older adults. Glaucoma is prevalent in this age group and may affect driving. The purpose of this study is to determine if glaucoma and glaucomatous visual field (VF) loss are associated with driving cessation, limitations, and deference to another driver in older adults. Cross-sectional study. Eighty-one glaucoma subjects and 58 glaucoma suspect controls between age 60 and 80 reported if they had ceased driving, limited their driving in various ways, or preferred another to drive. Twenty-three percent of glaucoma subjects and 6.9% of suspects had ceased driving (p = 0.01). Glaucoma subjects also had more driving limitations than suspects (2.0 vs. 1.1, p = 0.007). In multivariable models, driving cessation was more likely for glaucoma subjects as compared to suspects (OR = 4.0; 95% CI = 1.1-14.7; p = 0.03). The odds of driving cessation doubled with each 5 decibel (dB) decrement in the better-eye VF mean deviation (MD) (OR = 2.0; 95% CI = 1.4-2.9; p < 0.001). Glaucoma subjects were also more likely than suspects to report a greater number of driving limitations (OR = 4.7; 95% CI = 1.3-16.8; p = 0.02). The likelihood of reporting more limitations increased with the VF loss severity (OR = 1.6 per 5 dB decrement in the better-eye VF MD; 95% CI = 1.1-2.4; p = 0.02). Neither glaucoma nor VF MD was associated with other driver preference (p > 0.1 for both). Glaucoma and glaucomatous VF loss are associated with greater likelihood of driving cessation and greater limitation of driving in the elderly. Further prospective study is merited to assess when and why people with glaucoma change their driving habits, and to determine if their observed self-regulation of driving is adequate to ensure safety.

  2. Design of "Eye Closure" system for the stealth of photo-electric equipments

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Hua, W. S.; Li, G.

    2012-10-01

    Based on the optical activity of liquid crystal, a new approach for the stealth of "cat's eye" targets is proposed in this paper. It imitates the physiological close reaction of human eyes when strong light irradiates eyes. With this approach, the "cat's eye" effect will vanish, which is applied in restricting photo-electric equipments being detected and located by active laser detection system. The structure and working principle of the design are presented. The drive circuit is given to control the optical switch automatically. Feasibility of this design is demonstrated by experimental method. The measured data illustrate that the proposed approach is effective to eliminate the "cat's eye" effect, so as to enhancing the viability of photo-electric equipments on the battlefield.

  3. Drivers’ Visual Characteristics when Merging onto or Exiting an Urban Expressway

    PubMed Central

    Cheng, Ying; Gao, Li; Zhao, Yanan; Du, Feng

    2016-01-01

    The aim of this study is to examine drivers’ visual and driving behavior while merging onto or exiting an urban expressway with low and high traffic densities. The analysis was conducted according to three periods (approaching, merging or exiting, and accelerating or decelerating). A total of 10 subjects (8 males and 2 females) with ages ranging from 25 to 52 years old (M = 30.0 years old) participated in the study. The research was conducted in a natural driving situation, and the drivers’ eye movements were monitored and recorded using an eye tracking system. The results show that the influence of traffic density on the glance duration and scan duration is more significant when merging than when exiting. The results also demonstrate that the number of glances and the mean glance duration are mainly related to the driving task (e.g., the merging period). Therefore, drivers’ visual search strategies mainly depend on the current driving task. With regard to driving behavior, the variation tendencies of the duration and the velocity of each period are similar. These results support building an automated driving assistant system that can automatically identify gaps and accelerate or decelerate the car accordingly or provide suggestions to the driver to do so. PMID:27657888

  4. Objects predict fixations better than early saliency.

    PubMed

    Einhäuser, Wolfgang; Spain, Merrielle; Perona, Pietro

    2008-11-20

    Humans move their eyes while looking at scenes and pictures. Eye movements correlate with shifts in attention and are thought to be a consequence of optimal resource allocation for high-level tasks such as visual recognition. Models of attention, such as "saliency maps," are often built on the assumption that "early" features (color, contrast, orientation, motion, and so forth) drive attention directly. We explore an alternative hypothesis: Observers attend to "interesting" objects. To test this hypothesis, we measure the eye position of human observers while they inspect photographs of common natural scenes. Our observers perform different tasks: artistic evaluation, analysis of content, and search. Immediately after each presentation, our observers are asked to name objects they saw. Weighted with recall frequency, these objects predict fixations in individual images better than early saliency, irrespective of task. Also, saliency combined with object positions predicts which objects are frequently named. This suggests that early saliency has only an indirect effect on attention, acting through recognized objects. Consequently, rather than treating attention as mere preprocessing step for object recognition, models of both need to be integrated.

  5. Psychometric properties of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), Japanese version.

    PubMed

    Suzukamo, Yoshimi; Oshika, Tetsuro; Yuzawa, Mitsuko; Tokuda, Yoshihiro; Tomidokoro, Atsuo; Oki, Kotaro; Mangione, Carol M; Green, Joseph; Fukuhara, Shunichi

    2005-10-26

    The importance of evaluating the outcomes of health care from the standpoint of the patient is now widely recognized. The purpose of this study is to develop and test a Japanese version of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25). A Japanese version was developed with a previously standardized method. The questionnaire and optional items were completed by 245 patients with cataracts, glaucoma, or age-related macular degeneration, by 110 others before and after cataract surgery, and by a reference group (n = 31). We computed rates of missing data, measured reproducibility and internal consistency reliability, and tested for convergent and discriminant validity, concurrent validity, known-groups validity, factor structure, and responsiveness to change. Based on information from the participants, some items were changed to 2-step items (asking if an activity was done, and if it was done, then asking how difficult it was). The near-vision and distance-vision subscales each had 1 item that was endorsed by very few participants, so these items were replaced with items that were optional in the English version. For example, more than 60% of participants did not drive, so the driving question was excluded. Reliability and validity were adequate for all subscales except driving, ocular pain, color vision, and peripheral vision. With cataract surgery, most scores improved by at least 20 points. With minor modifications from the English version, the Japanese NEI VFQ-25 can give reliable, valid, responsive data on vision-related quality of life, for group-level comparisons or for tracking therapeutic outcomes.

  6. Eye-Movement Analysis of Students' Active Examination Strategy and Its Transfer in Visuospatial Representations

    ERIC Educational Resources Information Center

    Kim, Kinam; Kim, Minsung; Shin, Jungyeop; Ryu, Jaemyong

    2015-01-01

    This article examined the role of task demand and its effects on transfer in geographic learning. Student performance was measured through eye-movement analysis in two related experiments. In Experiment 1, the participants were told that they would travel through an area depicted in photographs either driving an automobile or observing the…

  7. Image analysis of ocular fundus for retinopathy characterization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ushizima, Daniela; Cuadros, Jorge

    2010-02-05

    Automated analysis of ocular fundus images is a common procedure in countries as England, including both nonemergency examination and retinal screening of patients with diabetes mellitus. This involves digital image capture and transmission of the images to a digital reading center for evaluation and treatment referral. In collaboration with the Optometry Department, University of California, Berkeley, we have tested computer vision algorithms to segment vessels and lesions in ground-truth data (DRIVE database) and hundreds of images of non-macular centric and nonuniform illumination views of the eye fundus from EyePACS program. Methods under investigation involve mathematical morphology (Figure 1) for imagemore » enhancement and pattern matching. Recently, we have focused in more efficient techniques to model the ocular fundus vasculature (Figure 2), using deformable contours. Preliminary results show accurate segmentation of vessels and high level of true-positive microaneurysms.« less

  8. Comparing spatially static and dynamic vibrotactile take-over requests in the driver seat.

    PubMed

    Petermeijer, S M; Cieler, S; de Winter, J C F

    2017-02-01

    Vibrotactile stimuli can be effective as warning signals, but their effectiveness as directional take-over requests in automated driving is yet unknown. This study aimed to investigate the correct response rate, reaction times, and eye and head orientation for static versus dynamic directional take-over requests presented via vibrating motors in the driver seat. In a driving simulator, eighteen participants performed three sessions: 1) a session involving no driving (Baseline), 2) driving a highly automated car without additional task (HAD), and 3) driving a highly automated car while performing a mentally demanding task (N-Back). Per session, participants received four directional static (in the left or right part of the seat) and four dynamic (moving from one side towards the opposite left or right of the seat) take-over requests via two 6×4 motor matrices embedded in the seat back and bottom. In the Baseline condition, participants reported whether the cue was left or right, and in the HAD and N-Back conditions participants had to change lanes to the left or to the right according to the directional cue. The correct response rate was operationalized as the accuracy of the self-reported direction (Baseline session) and the accuracy of the lane change direction (HAD & N-Back sessions). The results showed that the correct response rate ranged between 94% for static patterns in the Baseline session and 74% for dynamic patterns in the N-Back session, although these effects were not statistically significant. Steering wheel touch and steering input reaction times were approximately 200ms faster for static patterns than for dynamic ones. Eye tracking results revealed a correspondence between head/eye-gaze direction and lane change direction, and showed that head and eye-gaze movements where initiated faster for static vibrations than for dynamic ones. In conclusion, vibrotactile stimuli presented via the driver seat are effective as warnings, but their effectiveness as directional take-over requests may be limited. The present study may encourage further investigation into how to get drivers safely back into the loop. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Older drivers and cataract: driving habits and crash risk.

    PubMed

    Owsley, C; Stalvey, B; Wells, J; Sloane, M E

    1999-04-01

    Cataract is a leading cause of vision impairment in older adults, affecting almost half of those over age 75 years. Driving is a highly visual task and, as with other age groups, older adults rely on the personal automobile for travel. The purpose of this study was to examine the role of cataract in driving. Older adults (aged 55-85 years) with cataract (n = 279) and those without cataract (n = 105) who were legally licensed to drive were recruited from eye clinics to participate in a driving habits interview to assess driving status, exposure, difficulty, and "space" (the distance of driving excursions from home base). Crash data over the prior 5 years were procured from state records. Visual functional tests documented the severity of vision impairment. Compared to those without cataract, older drivers with cataract were approximately two times more likely to report reductions in days driven and number of destinations per week, driving slower than the general traffic flow, and preferring someone else to drive. Those with cataract were five times more likely to have received advice about limiting their driving. Those with cataract were four times more likely to report difficulty with challenging driving situations, and those reporting driving difficulty were two times more likely to reduce their driving exposure. Drivers with cataract were 2.5 times more likely to have a history of at-fault crash involvement in the prior 5 years (adjusted for miles driven/week and days driven/week). These associations remained even after adjustments for the confounding effects of advanced age, impaired general health, mental status deficit, or depression. Older drivers with cataract experience a restriction in their driving mobility and a decrease in their safety on the road. These findings serve as a baseline for our ongoing study evaluating whether improvements in vision following cataract surgery expand driving mobility and improve driver safety.

  10. Do older drivers with bilateral cataract self-regulate their driving while waiting for first eye cataract surgery?

    PubMed Central

    Agramunt, Seraina; Meuleners, Lynn B; Fraser, Michelle L; Chow, Kyle C; Ng, Jonathon Q; Raja, Vignesh; Morlet, Nigel

    2017-01-01

    Objectives To analyze the association between visual impairment and driver self-regulation among a cohort of older drivers waiting for first eye cataract surgery. Methods Ninety-six drivers with bilateral cataract aged 55+ years were assessed before first eye cataract surgery. Data collection consisted of a researcher-administered questionnaire, objective visual measures (visual acuity, contrast sensitivity and stereopsis), a visual attention test (the useful field of view test) and a cognitive test (the Mini-Mental State Examination). Driver self-regulation practices were collected using the Driving Habits Questionnaire and were also measured with an in-vehicle monitoring device. Characteristics of self-regulators and non-self-regulators were compared and a logistic regression model was used to examine the association between 3 objective visual measures and driver self-regulation status. Results After controlling for potential confounding factors, only binocular contrast sensitivity (p=0.01), age (p=0.03) and gender (p=0.03) were significantly associated with driver self-regulation status. The odds of participants with better contrast sensitivity scores (better vision) self-regulating their driving in at least 1 driving situation decreased (odds ratio [OR]: 0.01, 95% CI: 0.00–0.28) while those of increasing age reported an increased odds of self-regulating their driving (OR: 1.08, 95% CI: 1.01–1.15). The odds of males self-regulating their driving was decreased compared with females (OR: 0.28, 95% CI: 0.09–0.86). Conclusions Worse binocular contrast sensitivity scores, increasing age and being female were significantly associated with driver self-regulation. The study highlighted that while self-regulation was common among cataract patients, a proportion of those with poor vision did not self-regulate. Further research should determine how cataract patients could benefit from self-regulation strategies while waiting for cataract surgery. PMID:29184397

  11. Seeing Atoms and Molecules in Action with an Electron 'Eye' | Berkeley Lab

    Science.gov Websites

    , also called "electron guns," that can drive advanced X-ray lasers known as "free form of X-ray light. Free-electron lasers have opened new frontiers in studying materials and chemistry that you can look at with an X-ray free-electron laser, but with an electron eye." He added, "

  12. Corrected color glasses for effective protection of eyes

    NASA Astrophysics Data System (ADS)

    Ciosek, Jerzy

    2001-08-01

    The subject of modern and save sunglasses is entertaining to many people especially due to anti-UV eye protection. Many people use glasses with anti-UV or blue-block coatings to driving or sun-tanning. There were analyzed transmittance and reflectance of different sunglasses made with thin-layer coatings. Sunglasses with absorption-interference protection are specially interesting due to technical simplicity of production.

  13. Opportunity's Surroundings After Sol 1820 Drive (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11841 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11841

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009).

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  14. Feed Forward Programming of Car Drivers’ Eye Movement Behavior: A System Theoretical Approach. Volume 2

    DTIC Science & Technology

    1980-03-01

    a driver and emphasizes the potential applied value of this theoretical approach in improving driving safety . From a pragmatic point of view, it is...distance, there is less spare time to react after an essential target has been recognized. Because driving safety is of crucial importance under all con

  15. Wertheim's hypothesis on 'highway hypnosis': empirical evidence from a study on motorway and conventional road driving.

    PubMed

    Cerezuela, Gemma Pastor; Tejero, Pilar; Chóliz, Mariano; Chisvert, Mauricio; Monteagudo, M José

    2004-11-01

    This paper aims to study the phenomenon known as 'highway hypnosis' or 'driving without attention mode', which has been defined as a state showing sleepiness signs and attention slip resulting from driving a motor vehicle for a long period in a highly predictable environment with low event occurrence, this being the case with motorways and very familiar roads [Highway hypnosis: a theoretical analysis. In: Gale, A.G., Brown, I.D., Haslegrave, C.M., Moorhead, I., Taylor, S. (Eds.), Vision in Vehicles-III. Elsevier, North-Holland, pp. 467-472]. According to Wertheim's hypothesis on 'highway hypnosis', long-term driving on motorways and conventional roads, e.g. main roads, secondary roads--implies differences in the predictability of the movement pattern of the visual stimulation, in the eye musculature activity and in the type of feedback used in visual information processing (mostly extra-retinal on motorways and retinal and extra-retinal on conventional roads). All this ultimately leads to alertness differences between both road types. Our research is intended to provide empirical evidence from the hypothesis, based on the data recorded during the actual driving experience of a group of subjects on a motorway and a conventional road. We studied whether or not significant alertness differences were found-measured by EEG data relative to time periods of on-target eye-tracking performance--between motorway and conventional road driving. Our results partially support the hypothesis, as drowsiness proved to be higher on motorways than on conventional roads during the final driving period but not during the starting stage, when the opposite trend was noticed. This result could be explained by the fact that during the first driving periods the effects of the stimulus movement predictability had not yet become apparent, since they tend to show after a long drive.

  16. On the Visual Input Driving Human Smooth-Pursuit Eye Movements

    NASA Technical Reports Server (NTRS)

    Stone, Leland S.; Beutter, Brent R.; Lorenceau, Jean

    1996-01-01

    Current computational models of smooth-pursuit eye movements assume that the primary visual input is local retinal-image motion (often referred to as retinal slip). However, we show that humans can pursue object motion with considerable accuracy, even in the presence of conflicting local image motion. This finding indicates that the visual cortical area(s) controlling pursuit must be able to perform a spatio-temporal integration of local image motion into a signal related to object motion. We also provide evidence that the object-motion signal that drives pursuit is related to the signal that supports perception. We conclude that current models of pursuit should be modified to include a visual input that encodes perceived object motion and not merely retinal image motion. Finally, our findings suggest that the measurement of eye movements can be used to monitor visual perception, with particular value in applied settings as this non-intrusive approach would not require interrupting ongoing work or training.

  17. Comparing the Impact of Refractive and Non-Refractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation

    PubMed Central

    Zebardast, Nazlee; Swenor, Bonnielin K.; van Landingham, Suzanne W.; Massof, Robert W.; Munoz, Beatriz; West, Sheila K.; Ramulu, Pradeep Y.

    2015-01-01

    Purpose To compare the effects of uncorrected refractive error (URE) and non-refractive visual impairment (VI) on performance and disability measures. Design Cross-sectional population-based study. Participants 2469 individuals with binocular presenting visual acuity (PVA) of 20/80 or better who participated in the first round of the Salisbury Eye Evaluation study. Methods URE was defined as binocular PVA of 20/30 or worse, improving to better than 20/30 with subjective refraction. VI was defined as post-refraction binocular best corrected visual acuity (BCVA) of 20/30 or worse. The visual acuity decrement attributable to VI was calculated as the difference between BCVA and 20/30 while that due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of 1) vision status (VI, URE, or normal vision) using the group with normal vision as reference, and 2) a one-line decrement in acuity due to VI or URE. Main Outcome Measures Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. ADV responses were analyzed using Rasch analysis to determine visual ability. Results Compared to individuals with normal vision, subjects with VI (n=191) had significantly poorer objective and subjective visual functioning in all metrics examined (p<0.05) while subjects with URE (n=132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation and lower ADV scores (p<0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a one-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared to a one-line VA decrement due to URE. Conclusions VI is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and non-refractive vision loss should be distinguished in studies evaluating visual disability, and should be understood to have differing consequences. PMID:25813453

  18. Comparing the Impact of Refractive and Nonrefractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation.

    PubMed

    Zebardast, Nazlee; Swenor, Bonnielin K; van Landingham, Suzanne W; Massof, Robert W; Munoz, Beatriz; West, Sheila K; Ramulu, Pradeep Y

    2015-06-01

    To compare the effects of uncorrected refractive error (URE) and nonrefractive visual impairment (VI) on performance and disability measures. Cross-sectional, population-based study. A total of 2469 individuals with binocular presenting visual acuity (PVA) of ≥ 20/80 who participated in the first round of the Salisbury Eye Evaluation study. The URE was defined as binocular PVA of ≤ 20/30, improving to >20/30 with subjective refraction. The VI was defined as post-refraction binocular best-corrected visual acuity (BCVA) of ≤ 20/30. The visual acuity decrement due to VI was calculated as the difference between BCVA and 20/30, whereas visual acuity due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of (1) vision status (VI, URE, or normal vision) using the group with normal vision as reference and (2) a 1-line decrement in acuity due to VI or URE. Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. The ADV responses were analyzed using Rasch analysis to determine visual ability. Compared with individuals with normal vision, subjects with VI (n = 191) had significantly poorer objective and subjective visual functioning in all metrics examined (P < 0.05), whereas subjects with URE (n = 132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation, and lower ADV scores (P < 0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a 1-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared with a 1-line VA decrement due to URE. Visual impairment is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and nonrefractive vision loss should be distinguished in studies evaluating visual disability and be understood to have differing consequences. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  19. Functional outcome and patient satisfaction after laser in situ keratomileusis for correction of myopia and myopic astigmatism.

    PubMed

    Bamashmus, Mahfouth A; Hubaish, Khammash; Alawad, Mohammed; Alakhlee, Hisham

    2015-01-01

    The purpose was to evaluate subjective quality of vision and patient satisfaction after laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism. A self-administered patient questionnaire consisting 29 items was prospectively administered to LASIK patients at the Yemen Magrabi Hospital. Seven scales covering specific aspects of the quality of vision were formulated including; global satisfaction; quality of uncorrected and corrected vision; quality of night vision; glare; daytime driving and; night driving. Main outcome measures were responses to individual questions and scale scores and correlations with clinical parameters. The scoring scale ranged from 1 (dissatisfied) to 3 (very satisfied) and was stratified in the following manner: 1-1.65 = dissatisfied; 1.66-2.33 = satisfied and; 2.33-3 = very satisfied. Data at 6 months postoperatively are reported. This study sample was comprised of 200 patients (122 females: 78 males) ranging in age from 18 to 46 years old. The preoperative myopic sphere was - 3.50 ± 1.70 D and myopic astigmatism was 0.90 ± 0.82 D. There were 96% of eyes within ± 1.00 D of the targeted correction. Postoperatively, the uncorrected visual acuity was 20/40 or better in 99% of eyes. The mean score for the overall satisfaction was 2.64 ± 0.8. A total of 98.5% of patients was satisfied or very satisfied with their surgery, 98.5% considered their main goal for surgery was achieved. Satisfaction with uncorrected vision was 2.5 ± 0.50. The main score for glare was 1.98 ± 0.7 at night. Night driving was rated more difficult preoperatively by 6.2%, whereas 79% had less difficulty driving at night. Patient satisfaction with uncorrected vision after LASIK for myopia and myopic astigmatism appears to be excellent and is related to the residual refractive error postoperatively.

  20. Functional Outcome and Patient Satisfaction after Laser In Situ Keratomileusis for Correction of Myopia and Myopic Astigmatism

    PubMed Central

    Bamashmus, Mahfouth A.; Hubaish, Khammash; Alawad, Mohammed; Alakhlee, Hisham

    2015-01-01

    Purpose: The purpose was to evaluate subjective quality of vision and patient satisfaction after laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism. Patients and Methods: A self-administered patient questionnaire consisting 29 items was prospectively administered to LASIK patients at the Yemen Magrabi Hospital. Seven scales covering specific aspects of the quality of vision were formulated including; global satisfaction; quality of uncorrected and corrected vision; quality of night vision; glare; daytime driving and; night driving. Main outcome measures were responses to individual questions and scale scores and correlations with clinical parameters. The scoring scale ranged from 1 (dissatisfied) to 3 (very satisfied) and was stratified in the following manner: 1-1.65 = dissatisfied; 1.66-2.33 = satisfied and; 2.33-3 = very satisfied. Data at 6 months postoperatively are reported. Results: This study sample was comprised of 200 patients (122 females: 78 males) ranging in age from 18 to 46 years old. The preoperative myopic sphere was − 3.50 ± 1.70 D and myopic astigmatism was 0.90 ± 0.82 D. There were 96% of eyes within ± 1.00 D of the targeted correction. Postoperatively, the uncorrected visual acuity was 20/40 or better in 99% of eyes. The mean score for the overall satisfaction was 2.64 ± 0.8. A total of 98.5% of patients was satisfied or very satisfied with their surgery, 98.5% considered their main goal for surgery was achieved. Satisfaction with uncorrected vision was 2.5 ± 0.50. The main score for glare was 1.98 ± 0.7 at night. Night driving was rated more difficult preoperatively by 6.2%, whereas 79% had less difficulty driving at night. Conclusion: Patient satisfaction with uncorrected vision after LASIK for myopia and myopic astigmatism appears to be excellent and is related to the residual refractive error postoperatively. PMID:25624684

  1. Microcontroller based driver alertness detection systems to detect drowsiness

    NASA Astrophysics Data System (ADS)

    Adenin, Hasibah; Zahari, Rahimi; Lim, Tiong Hoo

    2018-04-01

    The advancement of embedded system for detecting and preventing drowsiness in a vehicle is a major challenge for road traffic accident systems. To prevent drowsiness while driving, it is necessary to have an alert system that can detect a decline in driver concentration and send a signal to the driver. Studies have shown that traffc accidents usually occur when the driver is distracted while driving. In this paper, we have reviewed a number of detection systems to monitor the concentration of a car driver and propose a portable Driver Alertness Detection System (DADS) to determine the level of concentration of the driver based on pixelated coloration detection technique using facial recognition. A portable camera will be placed at the front visor to capture facial expression and the eye activities. We evaluate DADS using 26 participants and have achieved 100% detection rate with good lighting condition and a low detection rate at night.

  2. TOPOGRAPHICALLY GUIDED LASIK FOR MYOPIA USING THE NIDEK CXII CUSTOMIZED ASPHERIC TREATMENT ZONE (CATZ)

    PubMed Central

    Waring, George; Dougherty, Paul J.; Chayet, Arturo; Fischer, Jeffery; Fant, Barbara; Stevens, Gary; Bains, Harkaran S.

    2007-01-01

    Purpose To assess the efficacy, predictability, and safety of topography-guided laser in situ keratomileusis (LASIK) for the surgical correction of low to moderate myopia with astigmatism using the Nidek CXIII excimer laser equipped with the customized aspheric treatment zone (CATz) algorithm. Methods In a multicenter US Food and Drug Administration study of topography-guided LASIK, 4 centers enrolled 135 eyes with manifest refraction sphere that ranged from −0.50 to −7.00 D (mean, −3.57 ± 1.45) with up to −4.00 D of astigmatism (mean, −1.02 ± 0.64 D). The intended outcome was plano in all eyes. Refractive outcomes and higher-order aberrations were analyzed preoperatively and postoperatively. Patient satisfaction was assessed using both the validated Refractive Status and Vision Profile (RSVP) questionnaire and a questionnaire designed for this study. Six-month postoperative outcomes are reported here. Results By 6 months postoperatively, the manifest refraction spherical equivalent (MRSE) for all eyes was −0.09 ± 0.31 D. Six months postoperatively, 116 of 131 eyes (88.55%) had an uncorrected visual acuity of 20/20 or better, and 122 of 131 eyes (93.13%) had a MRSE within ±0.50 D. Distance best spectacle-corrected visual acuity (BSCVA) increased by 2 or more lines in 21 of 131 eyes (19.01%), and no eyes lost 2 lines or more of BSCVA. The total ocular higher-order aberrations root-mean-square increased by 0.04 μm postoperatively. Patients reported significantly fewer night driving and glare and halo symptoms postoperatively than preoperatively. Conclusions Nidek CXIII CATz treatment of myopia with astigmatism is safe, efficacious, and predictable, and it reduces patient symptoms associated with night driving and glare and halo symptoms. PMID:18427614

  3. Impaired alertness and performance driving home from the night shift: a driving simulator study.

    PubMed

    Akerstedt, Torbjörn; Peters, Björn; Anund, Anna; Kecklund, Göran

    2005-03-01

    Driving in the early morning is associated with increased accident risk affecting not only professional drivers but also those who commute to work. The present study used a driving simulator to investigate the effects of driving home from a night shift. Ten shift workers participated after a normal night shift and after a normal night sleep. The results showed that driving home from the night shift was associated with an increased number of incidents (two wheels outside the lane marking, from 2.4 to 7.6 times), decreased time to first accident, increased lateral deviation (from 18 to 43 cm), increased eye closure duration (0.102 to 0.143 s), and increased subjective sleepiness. The results indicate severe postnight shift effects on sleepiness and driving performance.

  4. Challenges in detecting drowsiness based on driver’s behavior

    NASA Astrophysics Data System (ADS)

    Triyanti, V.; Iridiastadi, H.

    2017-12-01

    Drowsiness while driving has been a critical issue within the context of transportation safety. A number of approaches have been developed to reduce the risks of drowsy drivers. The mechanisms in detecting fatigue and sleepiness while driving has been categorized into three broad approaches, including vehicle-based, physiological-based, and behavior-based approaches. This paper will discuss recent studies in recognizing drowsy drivers based on their behaviors, particularly changes in eyes and facial characteristics. This paper will also address challenges in capturing aspects of natural expressions, driver responses, behavior, and task environment associated with sleepiness. Additionally, a number of technical aspects should be seriously considered, including correctly capturing face and eye characteristics from unwanted movements, unsuitable task environments, technological limitations, and individual differences.

  5. Effects of electronic billboards on driver distraction.

    PubMed

    Dukic, Tania; Ahlstrom, Christer; Patten, Christopher; Kettwich, Carmen; Kircher, Katja

    2013-01-01

    There is an increase in electronic advertising billboards along major roads, which may cause driver distraction due to the highly conspicuous design of the electronic billboards. Yet limited research on the impact of electronic billboards on driving performance and driver behavior is available. The Swedish Transport Administration recently approved the installation of 12 electronic billboards for a trial period along a 3-lane motorway with heavy traffic running through central Stockholm, Sweden. The aim of this study was to evaluate the effect of these electronic billboards on visual behavior and driving performance. A total of 41 drivers were recruited to drive an instrumented vehicle passing 4 of the electronic billboards during day and night conditions. A driver was considered visually distracted when looking at a billboard continuously for more than 2 s or if the driver looked away from the road for a high percentage of time. Dependent variables were eye-tracking measures and driving performance measures. The visual behavior data showed that drivers had a significantly longer dwell time, a greater number of fixations, and longer maximum fixation duration when driving past an electronic billboard compared to other signs on the same road stretches. No differences were found for the factors day/night, and no effect was found for the driving behavior data. Electronic billboards have an effect on gaze behavior by attracting more and longer glances than regular traffic signs. Whether the electronic billboards attract too much attention and constitute a traffic safety hazard cannot be answered conclusively based on the present data.

  6. Functional architecture of an optic flow-responsive area that drives horizontal eye movements in zebrafish.

    PubMed

    Kubo, Fumi; Hablitzel, Bastian; Dal Maschio, Marco; Driever, Wolfgang; Baier, Herwig; Arrenberg, Aristides B

    2014-03-19

    Animals respond to whole-field visual motion with compensatory eye and body movements in order to stabilize both their gaze and position with respect to their surroundings. In zebrafish, rotational stimuli need to be distinguished from translational stimuli to drive the optokinetic and the optomotor responses, respectively. Here, we systematically characterize the neural circuits responsible for these operations using a combination of optogenetic manipulation and in vivo calcium imaging during optic flow stimulation. By recording the activity of thousands of neurons within the area pretectalis (APT), we find four bilateral pairs of clusters that process horizontal whole-field motion and functionally classify eleven prominent neuron types with highly selective response profiles. APT neurons are prevalently direction selective, either monocularly or binocularly driven, and hierarchically organized to distinguish between rotational and translational optic flow. Our data predict a wiring diagram of a neural circuit tailored to drive behavior that compensates for self-motion. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Evidence of Anticipatory Eye Movements in the Spatial Hebb Repetition Effect: Insights for Modeling Sequence Learning

    ERIC Educational Resources Information Center

    Tremblay, Sebastien; Saint-Aubin, Jean

    2009-01-01

    In the present study, the authors offer a window onto the mechanisms that drive the Hebb repetition effect through the analysis of eye movement and recall performance. In a spatial serial recall task in which sequences of dots are to be remembered in order, when one particular series is repeated every 4 trials, memory performance markedly improves…

  8. 78 FR 24817 - Visual-Manual NHTSA Driver Distraction Guidelines for In-Vehicle Electronic Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-26

    ...The National Highway Traffic Safety Administration (NHTSA) is concerned about the effects of distraction on motor vehicle safety due to drivers' use of electronic devices. Consequently, NHTSA is issuing nonbinding, voluntary Driver Distraction Guidelines (NHTSA Guidelines) to promote safety by discouraging the introduction of excessively distracting devices in vehicles. This notice announces the issuance of the final version of the first phase of the NHTSA Guidelines. This first phase applies to original equipment (OE) in-vehicle electronic devices used by the driver to perform secondary tasks (communications, entertainment, information gathering, navigation tasks, etc. are considered secondary tasks) through visual-manual means (i.e., the driver looks at a device, manipulates a device-related control with his or her hand, and/or watches for visual feedback). The NHTSA Guidelines list certain secondary tasks believed by the agency to interfere inherently with a driver's ability to safely control the vehicle. The NHTSA Guidelines recommend that in-vehicle devices be designed so that they cannot be used by the driver to perform these inherently distracting secondary tasks while driving. For all other visual-manual secondary tasks, the NHTSA Guidelines specify a test method for measuring eye glance behavior during those tasks. Eye glance metrics are compared to acceptance criteria to evaluate whether a task interferes too much with driver attention, rendering it unsuitable for a driver to perform while driving. If a task does not meet the acceptance criteria, the NHTSA Guidelines recommend that the task be made inaccessible for performance by the driver while driving. In addition, the NHTSA Guidelines contain several recommendations to limit and reduce the potential for distraction associated with the use of OE in-vehicle electronic devices.

  9. Reliability and validity of abbreviated surveys derived from the National Eye Institute Visual Function Questionnaire: The Study of Osteoporotic Fractures

    PubMed Central

    Gergana, Kodjebacheva; Coleman, Anne L.; Ensrud, Kristine E.; Cauley, Jane A.; Yu, Fei; Stone, Katie L.; Pedula, Kathryn L.; Hochberg, Marc C.; Mangione, Carol M.

    2010-01-01

    Purpose To test the reliability and validity of questionnaires shortened from the National Eye Institute 25-item Vision Function Questionnaire (NEI VFQ-9 and NEI VFQ-8). Design A cross-sectional multi-center cohort study. Methods Reliability was assessed by Cronbach alpha coefficients. Validity was evaluated by studying the association of vision-targeted quality-of-life composite scores with objective visual function measurements. Study population: A total of 5,482 women between the ages of 65 and 100 years participated in the Year-10 clinic visit in the Study of Osteoporotic Fractures (SOF). A total of 3,631 women with complete data were included in the visual acuity (VA) and visual field (VF) analysis of the NEI VFQ-9, which is defined for those who care to drive. and 5,311 in the analysis of the NEI VFQ-8. To assess differences in prevalent eye diseases, which were ascertained for a random sample of SOF participants, 853 and 1,237 women were included in the NEI VFQ-9 and the NEI VFQ-8 analyses, respectively. Results Cronbach alpha coefficient for the NEI VFQ-9 scale was 0.83 and that of the NEI VFQ-8 was 0.84. Using both questionnaires, women with VA worse than 20/40 had lower composite scores compared to those with VA 20/40 or better (p<0.001). Participants with mild, moderate, and severe binocular VF loss had lower composite scores compared to those with no binocular VF loss (p<0.001).Compared to women without chronic eye diseases in both eyes, women with at least one chronic eye disease in at least one eye had lower composite scores. Conclusions Both questionnaires showed high reliability across items and validity with respect to clinical markers of eye disease Future research should compare the properties of these shortened surveys to those of the NEI VFQ-25. PMID:20103058

  10. A meta-analysis of the effects of texting on driving.

    PubMed

    Caird, Jeff K; Johnston, Kate A; Willness, Chelsea R; Asbridge, Mark; Steel, Piers

    2014-10-01

    Text messaging while driving is considered dangerous and known to produce injuries and fatalities. However, the effects of text messaging on driving performance have not been synthesized or summarily estimated. All available experimental studies that measured the effects of text messaging on driving were identified through database searches using variants of "driving" and "texting" without restriction on year of publication through March 2014. Of the 1476 abstracts reviewed, 82 met general inclusion criteria. Of these, 28 studies were found to sufficiently compare reading or typing text messages while driving with a control or baseline condition. Independent variables (text-messaging tasks) were coded as typing, reading, or a combination of both. Dependent variables included eye movements, stimulus detection, reaction time, collisions, lane positioning, speed and headway. Statistics were extracted from studies to compute effect sizes (rc). A total sample of 977 participants from 28 experimental studies yielded 234 effect size estimates of the relationships among independent and dependent variables. Typing and reading text messages while driving adversely affected eye movements, stimulus detection, reaction time, collisions, lane positioning, speed and headway. Typing text messages alone produced similar decrements as typing and reading, whereas reading alone had smaller decrements over fewer dependent variables. Typing and reading text messages affects drivers' capability to adequately direct attention to the roadway, respond to important traffic events, control a vehicle within a lane and maintain speed and headway. This meta-analysis provides convergent evidence that texting compromises the safety of the driver, passengers and other road users. Combined efforts, including legislation, enforcement, blocking technologies, parent modeling, social media, social norms and education, will be required to prevent continued deaths and injuries from texting and driving. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. The impairing effects of mental fatigue on response inhibition: An ERP study

    PubMed Central

    Guo, Zizheng; Chen, Ruiya; Liu, Xian; Zheng, Yan; Gong, Mingliang; Zhang, Jun

    2018-01-01

    Mental fatigue is one of the main reasons for the decline of response inhibition. This study aimed to explore the impairing influence of mental fatigue on a driver’s response inhibition. The effects of mental fatigue on response inhibition were assessed by comparing brain activity and behavioral indices when performing a Go/NoGo task before and after a 90-min fatigue manipulation task. Participants in the driving group performed a simulated driving task, while individuals in the control group spent the same time watching movies. We found that participants in the driving group reported higher levels of mental fatigue and had a higher percentage of eye closure and larger lateral deviations from their lane positions, which indicated there was effective manipulation of mental fatigue through a prolonged simulated driving task. After manipulation of mental fatigue, we observed increased reaction time and miss rates, delayed NoGo-N2 latency and Go-P3 latency, and decreased NoGo-P3 amplitude, which indicated that mental fatigue may slow down the speed of the inhibition process, delay the evaluation of visual stimuli and reduce the availability of attentional resources. These findings revealed the underlying neurological mechanisms of how mental fatigue impaired response inhibition. PMID:29856827

  12. Practical landmarks for visual field disability in glaucoma.

    PubMed

    Saunders, Luke J; Russell, Richard A; Crabb, David P

    2012-09-01

    To assess whether mean deviation (MD) from automated perimetry is related to the visual field (VF) component for legal fitness to drive (LFTD) in glaucoma patients. Monocular 24-2 VFs of 2604 patients with bilateral VF damage were retrospectively investigated. Integrated visual fields were calculated and used as a surrogate to assess LFTD according to current UK driving licence criteria. The better eye MD (BEMD), worse eye MD (WEMD) and a measure utilising MD of both eyes were compared, to assess respective diagnostic capabilities to predict LFTD (using the integrated visual field surrogate test as the gold standard) and a 'Probability of Failure' (PoF) for various defect levels was calculated. BEMD appears to be a good predictor of the VF component for a patient's LFTD (receiver operating characteristic area under the curve: 96.2%); MDs from both eyes offered no significant extra diagnostic power (area under the curve: 96.4%). PoF for BEMD thresholds of ≤-10 dB and ≤-14 dB were 70 (95% CI 66% to 74%) and 92% (87% to 95%), respectively. There is a strong relationship between BEMD and a patient's LFTD. PoF values for LFTD associated with readily available MD values provide practical landmarks for VF disability in glaucoma.

  13. Direction of Perceived Motion and Eye Movements Show Similar Biases for Asymmetrically Windowed Moving Plaids

    NASA Technical Reports Server (NTRS)

    Beutter, B. R.; Mulligan, J. B.; Stone, L. S.; Hargens, Alan R. (Technical Monitor)

    1995-01-01

    We have shown that moving a plaid in an asymmetric window biases the perceived direction of motion (Beutter, Mulligan & Stone, ARVO 1994). We now explore whether these biased motion signals might also drive the smooth eye-movement response by comparing the perceived and tracked directions. The human smooth oculomotor response to moving plaids appears to be driven by the perceived rather than the veridical direction of motion. This suggests that human motion perception and smooth eye movements share underlying neural motion-processing substrates as has already been shown to be true for monkeys.

  14. Ketorolac Ophthalmic

    MedlinePlus

    ... soft contact lenses. You should not use ketorolac eye drops while wearing your soft contact lenses.use caution when driving or operating machinery because your vision may be blurred after you instill the drops.

  15. Visual function of drivers and its relationship to road traffic accidents in Urban Africa.

    PubMed

    Pepple, Godswill; Adio, Adedayo

    2014-01-01

    Nigeria has one of the highest mortality rates from Road traffic accidents (RTAs). Prevention is a global priority. This study is aimed at acquiring information for effective policy formulation to improve safety on Nigerian roads. This is a cross sectional descriptive study in which consenting commercial drivers in a Nigerian motor parks were ophthalmically examined after an interview. Data analyzed with EPI-INFO version 6.0 statistical software using Chi square. P value < 0.05 was considered to be significant. The eyes of 400 commercial drivers were examined. Ages range from 25 to 62 years with mean of 37.8 years (SD ± 9.1) 20% did not undergo any prior driving test and only one third of those who had (n = 120, 30.9%) had a prior eye test. Up to 45.5% (n = 182) had been involved in RTAs with alcohol intoxication and driver fatigue significantly associated. Depressants such as alcohol are commonly used. Visual impairment ((p = 0.46, χ (2) = 0.3, RR = 0.62), visual field defects (p > 0.05, χ(2) = 0.78, RR = 1.25) and color vision defects (p = 0.4, χ (2) = 0.77, RR = 1.23) were not significantly associated with occurrence of RTAs. However fatigue was found to be a predisposing factor in 28% of those who had RTAs. One out of every two commercial driver has been involved in an RTA in the past in Nigeria. Fatigue while driving should be avoided. Use of depressants while driving should be penalized. Blood alcohol content (BAC) levels should routinely be measured by road safety personnel in Nigeria. Periodic eye exams should be carried out for all commercial drivers before issuing or renewing licenses to drive and treatment for any ophthalmic conditions discovered enforced.

  16. Psychological distress and visual functioning in relation to vision-related disability in older individuals with cataracts.

    PubMed

    Walker, J G; Anstey, K J; Lord, S R

    2006-05-01

    To determine whether demographic, health status and psychological functioning measures, in addition to impaired visual acuity, are related to vision-related disability. Participants were 105 individuals (mean age=73.7 years) with cataracts requiring surgery and corrected visual acuity in the better eye of 6/24 to 6/36 were recruited from waiting lists at three public out-patient ophthalmology clinics. Visual disability was measured with the Visual Functioning-14 survey. Visual acuity was assessed using better and worse eye logMAR scores and the Melbourne Edge Test (MET) for edge contrast sensitivity. Data relating to demographic information, depression, anxiety and stress, health care and medication use and numbers of co-morbid conditions were obtained. Principal component analysis revealed four meaningful factors that accounted for 75% of the variance in visual disability: recreational activities, reading and fine work, activities of daily living and driving behaviour. Multiple regression analyses determined that visual acuity variables were the only significant predictors of overall vision-related functioning and difficulties with reading and fine work. For the remaining visual disability domains, non-visual factors were also significant predictors. Difficulties with recreational activities were predicted by stress, as well as worse eye visual acuity, and difficulties with activities of daily living were associated with self-reported health status, age and depression as well as MET contrast scores. Driving behaviour was associated with sex (with fewer women driving), depression, anxiety and stress scores, and MET contrast scores. Vision-related disability is common in older individuals with cataracts. In addition to visual acuity, demographic, psychological and health status factors influence the severity of vision-related disability, affecting recreational activities, activities of daily living and driving.

  17. A Critical Review of the Drug/Performance Literature. Volume I.

    DTIC Science & Technology

    1979-12-01

    70 Information Processing ---------------------------------- 71 Eye Movement Studies------------------------------------ 72 IF...77 Memory and Information Processing ------------------------ 79 State-Dependent Learning---------------------------------- 81 Driving...Information Processing ------------------------------ 163 Decisionmaking--------------------------------------- 166 Communication Skills

  18. Eye regression in blind Astyanax cavefish may facilitate the evolution of an adaptive behavior and its sensory receptors.

    PubMed

    Borowsky, Richard

    2013-07-11

    The forces driving the evolutionary loss or simplification of traits such as vision and pigmentation in cave animals are still debated. Three alternative hypotheses are direct selection against the trait, genetic drift, and indirect selection due to antagonistic pleiotropy. Recent work establishes that Astyanax cavefish exhibit vibration attraction behavior (VAB), a presumed behavioral adaptation to finding food in the dark not exhibited by surface fish. Genetic analysis revealed two regions in the genome with quantitative trait loci (QTL) for both VAB and eye size. These observations were interpreted as genetic evidence that selection for VAB indirectly drove eye regression through antagonistic pleiotropy and, further, that this is a general mechanism to account for regressive evolution. These conclusions are unsupported by the data; the analysis fails to establish pleiotropy and ignores the numerous other QTL that map to, and potentially interact, in the same regions. It is likely that all three forces drive evolutionary change. We will be able to distinguish among them in individual cases only when we have identified the causative alleles and characterized their effects.

  19. Exploring the Use of Molecular Biomarkers for Precision Medicine in Age-Related Macular Degeneration.

    PubMed

    Lorés-Motta, Laura; de Jong, Eiko K; den Hollander, Anneke I

    2018-06-01

    Precision medicine aims to improve patient care by adjusting medication to each patient's individual needs. Age-related macular degeneration (AMD) is a heterogeneous eye disease in which several pathways are involved, and the risk factors driving the disease differ per patient. As a consequence, precision medicine holds promise for improved management of this disease, which is nowadays a main cause of vision loss in the elderly. In this review, we provide an overview of the studies that have evaluated the use of molecular biomarkers to predict response to treatment in AMD. We predominantly focus on genetic biomarkers, but also include studies that examined circulating or eye fluid biomarkers in treatment response. This involves studies on treatment response to dietary supplements, response to anti-vascular endothelial growth factor, and response to complement inhibitors. In addition, we highlight promising new therapies that have been or are currently being tested in clinical trials and discuss the molecular studies that can help identify the most suitable patients for these upcoming therapeutic approaches.

  20. The relationship between better-eye and integrated visual field mean deviation and visual disability.

    PubMed

    Arora, Karun S; Boland, Michael V; Friedman, David S; Jefferys, Joan L; West, Sheila K; Ramulu, Pradeep Y

    2013-12-01

    To determine the extent of difference between better-eye visual field (VF) mean deviation (MD) and integrated VF (IVF) MD among Salisbury Eye Evaluation (SEE) subjects and a larger group of glaucoma clinic subjects and to assess how those measures relate to objective and subjective measures of ability/performance in SEE subjects. Retrospective analysis of population- and clinic-based samples of adults. A total of 490 SEE and 7053 glaucoma clinic subjects with VF loss (MD ≤-3 decibels [dB] in at least 1 eye). Visual field testing was performed in each eye, and IVF MD was calculated. Differences between better-eye and IVF MD were calculated for SEE and clinic-based subjects. In SEE subjects with VF loss, models were constructed to compare the relative impact of better-eye and IVF MD on driving habits, mobility, self-reported vision-related function, and reading speed. Difference between better-eye and IVF MD and relationship of better-eye and IVF MD with performance measures. The median difference between better-eye and IVF MD was 0.41 dB (interquartile range [IQR], -0.21 to 1.04 dB) and 0.72 dB (IQR, 0.04-1.45 dB) for SEE subjects and clinic-based patients with glaucoma, respectively, with differences of ≥ 2 dB between the 2 MDs observed in 9% and 18% of the groups, respectively. Among SEE subjects with VF loss, both MDs demonstrated similar associations with multiple ability and performance metrics as judged by the presence/absence of a statistically significant association between the MD and the metric, the magnitude of observed associations (odds ratios, rate ratios, or regression coefficients associated with 5-dB decrements in MD), and the extent of variability in the metric explained by the model (R(2)). Similar associations of similar magnitude also were noted for the subgroup of subjects with glaucoma and subjects in whom better-eye and IVF MD differed by ≥ 2 dB. The IVF MD rarely differs from better-eye MD, and similar associations between VF loss and visual disability are obtained using either MD. Unlike better-eye MD, IVF measurements require extra software/calculation. As such, information from studies using better-eye MD can be more easily integrated into clinical decision-making, making better-eye MD a robust and meaningful method for reporting VF loss severity. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  1. Volitional control of anticipatory ocular pursuit responses under stabilised image conditions in humans.

    PubMed

    Barnes, G; Goodbody, S; Collins, S

    1995-01-01

    Ocular pursuit responses have been examined in humans in three experiments in which the pursuit target image has been fully or partially stabilised on the fovea by feeding a recorded eye movement signal back to drive the target motion. The objective was to establish whether subjects could volitionally control smooth eye movement to reproduce trajectories of target motion in the absence of a concurrent target motion stimulus. In experiment 1 subjects were presented with a target moving with a triangular waveform in the horizontal axis with a frequency of 0.325 Hz and velocities of +/- 10-50 degrees/s. The target was illuminated twice per cycle for pulse durations (PD) of 160-640 ms as it passed through the centre position; otherwise subjects were in darkness. Subjects initially tracked the target motion in a conventional closed-loop mode for four cycles. Prior to the next target presentation the target image was stabilised on the fovea, so that any target motion generated resulted solely from volitional eye movement. Subjects continued to make anticipatory smooth eye movements both to the left and the right with a velocity trajectory similar to that observed in the closed-loop phase. Peak velocity in the stabilised-image mode was highly correlated with that in the prior closed-loop phase, but was slightly less (84% on average). In experiment 2 subjects were presented with a continuously illuminated target that was oscillated sinusoidally at frequencies of 0.2-1.34 Hz and amplitudes of +/- 5-20 degrees. After four cycles of closed-loop stimulation the image was stabilised on the fovea at the time of peak target displacement. Subjects continued to generate an oscillatory smooth eye velocity pattern that mimicked the sinusoidal motion of the previous closed-loop phase for at least three further cycles. The peak eye velocity generated ranged from 57-95% of that in the closed-loop phase at frequencies up to 0.8 Hz but decreased significantly at 1.34 Hz. In experiment 3 subjects were presented with a stabilised display throughout and generated smooth eye movements with peak velocity up to 84 degrees/s in the complete absence of any prior external target motion stimulus, by transferring their attention alternately to left and right of the centre of the display. Eye velocity was found to be dependent on the eccentricity of the centre of attention and the frequency of alternation. When the target was partially stabilised on the retina by feeding back only a proportion (Kf = 0.6-0.9) of the eye movement signal to drive the target, subjects were still able to generate smooth movements at will, even though the display did not move as far or as fast as the eye. Peak eye velocity decreased as Kf decreased, suggesting that there was a continuous competitive interaction between the volitional drive and the visual feedback provided by the relative motion of the display with respect to the retina. These results support the evidence for two separate mechanisms of smooth eye movement control in ocular pursuit: reflex control from retinal velocity error feedback and volitional control from an internal source. Arguments are presented to indicate how smooth pursuit may be controlled by matching a voluntarily initiated estimate of the required smooth movement, normally derived from storage of past re-afferent information, against current visual feedback information. Such a mechanism allows preemptive smooth eye movements to be made that can overcome the inherent delays in the visual feedback pathway.

  2. Take-over performance in evasive manoeuvres.

    PubMed

    Happee, Riender; Gold, Christian; Radlmayr, Jonas; Hergeth, Sebastian; Bengler, Klaus

    2017-09-01

    We investigated after effects of automation in take-over scenarios in a high-end moving-base driving simulator. Drivers performed evasive manoeuvres encountering a blocked lane in highway driving. We compared the performance of drivers 1) during manual driving, 2) after automated driving with eyes on the road while performing the cognitively demanding n-back task, and 3) after automated driving with eyes off the road performing the visually demanding SuRT task. Both minimum time to collision (TTC) and minimum clearance towards the obstacle disclosed a substantial number of near miss events and are regarded as valuable surrogate safety metrics in evasive manoeuvres. TTC proved highly sensitive to the applied definition of colliding paths, and we prefer robust solutions using lane position while disregarding heading. The extended time to collision (ETTC) which takes into account acceleration was close to the more robust conventional TTC. In line with other publications, the initial steering or braking intervention was delayed after using automation compared to manual driving. This resulted in lower TTC values and stronger steering and braking actions. Using automation, effects of cognitive distraction were similar to visual distraction for the intervention time with effects on the surrogate safety metric TTC being larger with visual distraction. However the precision of the evasive manoeuvres was hardly affected with a similar clearance towards the obstacle, similar overshoots and similar excursions to the hard shoulder. Further research is needed to validate and complement the current simulator based results with human behaviour in real world driving conditions. Experiments with real vehicles can disclose possible systematic differences in behaviour, and naturalistic data can serve to validate surrogate safety measures like TTC and obstacle clearance in evasive manoeuvres. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  3. Examining signs of driver sleepiness, usage of sleepiness countermeasures and the associations with sleepy driving behaviours and individual factors.

    PubMed

    Watling, Christopher N; Armstrong, Kerry A; Radun, Igor

    2015-12-01

    The impairing effect from sleepiness is a major contributor to road crashes. The ability of a sleepy driver to perceive their level of sleepiness is an important consideration for road safety as well as the type of sleepiness countermeasure used by drivers as some sleepiness countermeasures are more effective than others. The aims of the current study were to determine the extent that the signs of driver sleepiness were associated with sleepy driving behaviours, as well as determining which individual factors (demographic, work, driving, and sleep-related factors) were associated with using a roadside or in-vehicle sleepiness countermeasure. A sample of 1518 Australian drivers from the Australian State of New South Wales and the neighbouring Australian Capital Territory took part in the study. The participants' experiences with the signs of sleepiness were reasonably extensive. A number of the early signs of sleepiness (e.g., yawning, frequent eye blinks) were related with continuing to drive while sleepy, with the more advanced signs of sleepiness (e.g., difficulty keeping eyes open, dreamlike state of consciousness) associated with having a sleep-related close call. The individual factors associated with using a roadside sleepiness countermeasure included age (being older), education (tertiary level), difficulties getting to sleep, not continuing to drive while sleepy, and having experienced many signs of sleepiness. The results suggest that these participants have a reasonable awareness and experience with the signs of driver sleepiness. Factors related to previous experiences with sleepiness were associated with implementing a roadside countermeasure. Nonetheless, the high proportions of drivers performing sleepy driving behaviours suggest that concerted efforts are needed with road safety campaigns regarding the dangers of driving while sleepy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Are anxiety and fear separable emotions in driving? A laboratory study of behavioural and physiological responses to different driving environments.

    PubMed

    Barnard, M P; Chapman, P

    2016-01-01

    Research into anxiety and driving has indicated that those higher in anxiety are potentially more dangerous on the roads. However, simulator findings suggest that conclusions are mixed at best. It is possible that anxiety is becoming confused with fear, which has a focus on more clearly defined sources of threat from the environment, as opposed to the internal, thought-related process associated with anxiety. This research aimed to measure feelings of fear, as well as physiological and attentional reactions to increasing levels of accident risk. Trait anxiety was also measured to see if it interacted with levels of risk or its associated reactions. Participants watched videos of driving scenarios with varying levels of accident risk and had to rate how much fear they would feel if they were the driver of the car, whilst skin conductance, heart rate, and eye movements were recorded. Analysis of the data suggested that perceptions of fear increased with increasing levels of accident risk, and skin conductance reflected this pattern. Eye movements, when considered alongside reaction times, indicated different patterns of performance according to different dangerous situations. These effects were independent of trait anxiety, which was only associated with higher rates of disliking driving and use of maladaptive coping mechanisms on questionnaires. It is concluded that these results could provide useful evidence in support for training-based programmes; it may also be beneficial to study trait anxiety within a more immersive driving environment and on a larger scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Glaucomatous retinal nerve fiber layer thickness loss is associated with slower reaction times under a divided attention task.

    PubMed

    Tatham, Andrew J; Boer, Erwin R; Rosen, Peter N; Della Penna, Mauro; Meira-Freitas, Daniel; Weinreb, Robert N; Zangwill, Linda M; Medeiros, Felipe A

    2014-11-01

    To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving. Cross-sectional observational study. Hamilton Glaucoma Center, University of California San Diego. Total of 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls. Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium, or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measure retinal nerve fiber layer (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire. Reaction times to the driving simulator divided attention task. The mean reaction times to the low-contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls, respectively, during curve negotiation (P < .001), and 1.19 s and 0.77 s (P = .025), respectively, during car following. There was a nonlinear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability, and central driving task performance. Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Changed processing of visual sexual stimuli under GnRH-therapy--a single case study in pedophilia using eye tracking and fMRI.

    PubMed

    Jordan, Kirsten; Fromberger, Peter; Laubinger, Helge; Dechent, Peter; Müller, Jürgen L

    2014-05-17

    Antiandrogen therapy (ADT) has been used for 30 years to treat pedophilic patients. The aim of the treatment is a reduction in sexual drive and, in consequence, a reduced risk of recidivism. Yet the therapeutic success of antiandrogens is uncertain especially regarding recidivism. Meta-analyses and reviews report only moderate and often mutually inconsistent effects. Based on the case of a 47 year old exclusively pedophilic forensic inpatient, we examined the effectiveness of a new eye tracking method and a new functional magnetic resonance imaging (fMRI)-design in regard to the evaluation of ADT in pedophiles. We analyzed the potential of these methods in exploring the impact of ADT on automatic and controlled attentional processes in pedophiles. Eye tracking and fMRI measures were conducted before the initial ADT as well as four months after the onset of ADT. The patient simultaneously viewed an image of a child and an image of an adult while eye movements were measured. During the fMRI-measure the same stimuli were presented subliminally. Eye movements demonstrated that controlled attentional processes change under ADT, whereas automatic processes remained mostly unchanged. We assume that these results reflect either the increased ability of the patient to control his eye movements while viewing prepubertal stimuli or his better ability to manipulate his answer in a socially desirable manner. Unchanged automatic attentional processes could reflect the stable pedophilic preference of the patient. Using fMRI, the subliminal presentation of sexually relevant stimuli led to changed activation patterns under the influence of ADT in occipital and parietal brain regions, the hippocampus, and also in the orbitofrontal cortex. We suggest that even at an unconscious level ADT can lead to changed processing of sexually relevant stimuli, reflecting changes of cognitive and perceptive automatic processes. We are convinced that our experimental designs using eye tracking and fMRI could prospectively add additional and valuable information in the evaluation of ADT in paraphilic patients and sex offenders. But with respect to the limited significance of this single case study, these first results are preliminary and further studies have to be conducted with healthy subjects and patients.

  7. Changed processing of visual sexual stimuli under GnRH-therapy – a single case study in pedophilia using eye tracking and fMRI

    PubMed Central

    2014-01-01

    Background Antiandrogen therapy (ADT) has been used for 30 years to treat pedophilic patients. The aim of the treatment is a reduction in sexual drive and, in consequence, a reduced risk of recidivism. Yet the therapeutic success of antiandrogens is uncertain especially regarding recidivism. Meta-analyses and reviews report only moderate and often mutually inconsistent effects. Case presentation Based on the case of a 47 year old exclusively pedophilic forensic inpatient, we examined the effectiveness of a new eye tracking method and a new functional magnetic resonance imaging (fMRI)-design in regard to the evaluation of ADT in pedophiles. We analyzed the potential of these methods in exploring the impact of ADT on automatic and controlled attentional processes in pedophiles. Eye tracking and fMRI measures were conducted before the initial ADT as well as four months after the onset of ADT. The patient simultaneously viewed an image of a child and an image of an adult while eye movements were measured. During the fMRI-measure the same stimuli were presented subliminally. Eye movements demonstrated that controlled attentional processes change under ADT, whereas automatic processes remained mostly unchanged. We assume that these results reflect either the increased ability of the patient to control his eye movements while viewing prepubertal stimuli or his better ability to manipulate his answer in a socially desirable manner. Unchanged automatic attentional processes could reflect the stable pedophilic preference of the patient. Using fMRI, the subliminal presentation of sexually relevant stimuli led to changed activation patterns under the influence of ADT in occipital and parietal brain regions, the hippocampus, and also in the orbitofrontal cortex. We suggest that even at an unconscious level ADT can lead to changed processing of sexually relevant stimuli, reflecting changes of cognitive and perceptive automatic processes. Conclusion We are convinced that our experimental designs using eye tracking and fMRI could prospectively add additional and valuable information in the evaluation of ADT in paraphilic patients and sex offenders. But with respect to the limited significance of this single case study, these first results are preliminary and further studies have to be conducted with healthy subjects and patients. PMID:24885644

  8. Multi-modal demands of a smartphone used to place calls and enter addresses during highway driving relative to two embedded systems.

    PubMed

    Reimer, Bryan; Mehler, Bruce; Reagan, Ian; Kidd, David; Dobres, Jonathan

    2016-12-01

    There is limited research on trade-offs in demand between manual and voice interfaces of embedded and portable technologies. Mehler et al. identified differences in driving performance, visual engagement and workload between two contrasting embedded vehicle system designs (Chevrolet MyLink and Volvo Sensus). The current study extends this work by comparing these embedded systems with a smartphone (Samsung Galaxy S4). None of the voice interfaces eliminated visual demand. Relative to placing calls manually, both embedded voice interfaces resulted in less eyes-off-road time than the smartphone. Errors were most frequent when calling contacts using the smartphone. The smartphone and MyLink allowed addresses to be entered using compound voice commands resulting in shorter eyes-off-road time compared with the menu-based Sensus but with many more errors. Driving performance and physiological measures indicated increased demand when performing secondary tasks relative to 'just driving', but were not significantly different between the smartphone and embedded systems. Practitioner Summary: The findings show that embedded system and portable device voice interfaces place fewer visual demands on the driver than manual interfaces, but they also underscore how differences in system designs can significantly affect not only the demands placed on drivers, but also the successful completion of tasks.

  9. A Review of Hazard Anticipation Training Programs for Young Drivers

    PubMed Central

    McDonald, Catherine C.; Goodwin, Arthur H.; Pradhan, Anuj K.; Romoser, Matthew R.E.; Williams, Allan F.

    2015-01-01

    Purpose Poor hazard anticipation skills are a risk factor associated with high motor vehicle crash rates of young drivers. A number of programs have been developed to improve these skills. The purpose of this review was to assess the empirical literature on hazard anticipation training for young drivers. Methods Studies were included if they: 1) included an assessment of hazard anticipation training outcomes; 2) were published between January 1, 1980 and December 31, 2013 in an English language peer-reviewed journal or conference proceeding; and 3) included at least one group that uniquely comprised a cohort of participants <21 years. Nineteen studies met inclusion criteria. Results Studies used a variety of training methods including interactive computer programs, videos, simulation, commentary driving, or a combination of approaches. Training effects were predominantly measured through computer-based testing and driving simulation with eye tracking. Four studies included an on-road evaluation. Most studies evaluated short-term outcomes (immediate or few days). In all studies, young drivers showed improvement in selected hazard anticipation outcomes, but none investigated crash effects. Conclusions Although there is promise in existing programs, future research should include long-term follow up, evaluate crash outcomes, and assess the optimal timing of hazard anticipation training taking into account the age and experience level of young drivers. PMID:26112734

  10. Effect of passengers' active head tilt and opening/closure of eyes on motion sickness in lateral acceleration environment of cars.

    PubMed

    Wada, Takahiro; Yoshida, Keigo

    2016-08-01

    This study examined the effect of passengers' active head-tilt and eyes-open/eyes-closed conditions on the severity of motion sickness in the lateral acceleration environment of cars. In the centrifugal head-tilt condition, participants intentionally tilted their heads towards the centrifugal force, whereas in the centripetal head-tilt condition, the participants tilted their heads against the centrifugal acceleration. The eyes-open and eyes-closed cases were investigated for each head-tilt condition. In the experimental runs, the sickness rating in the centripetal head-tilt condition was significantly lower than that in the centrifugal head-tilt condition. Moreover, the sickness rating in the eyes-open condition was significantly lower than that in the eyes-closed condition. The results suggest that an active head-tilt motion against the centrifugal acceleration reduces the severity of motion sickness both in the eyes-open and eyes-closed conditions. They also demonstrate that the eyes-open condition significantly reduces the motion sickness even when the head-tilt strategy is used. Practitioner Summary: Little is known about the effect of head-tilt strategies on motion sickness. This study investigated the effects of head-tilt direction and eyes-open/eyes-closed conditions on motion sickness during slalom automobile driving. Passengers' active head tilt towards the centripetal direction and the eyes-open condition greatly reduce the severity of motion sickness.

  11. Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic

    PubMed Central

    Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

    2016-01-01

    Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment. PMID:26785293

  12. Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic.

    PubMed

    Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

    2016-01-19

    Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment.

  13. Evaluation of Different Speech and Touch Interfaces to In-Vehicle Music Retrieval Systems

    PubMed Central

    Garay-Vega, L.; Pradhan, A. K.; Weinberg, G.; Schmidt-Nielsen, B.; Harsham, B.; Shen, Y.; Divekar, G.; Romoser, M.; Knodler, M.; Fisher, D. L.

    2010-01-01

    In-vehicle music retrieval systems are becoming more and more popular. Previous studies have shown that they pose a real hazard to drivers when the interface is a tactile one which requires multiple entries and a combination of manual control and visual feedback. Voice interfaces exist as an alternative. Such interfaces can require either multiple or single conversational turns. In this study, each of 17 participants between the ages of 18 and 30 years old was asked to use three different music-retrieval systems (one with a multiple entry touch interface, the iPod™, one with a multiple turn voice interface, interface B, and one with a single turn voice interface, interface C) while driving through a virtual world. Measures of secondary task performance, eye behavior, vehicle control, and workload were recorded. When compared with the touch interface, the voice interfaces reduced the total time drivers spent with their eyes off the forward roadway, especially in prolonged glances, as well as both the total number of glances away from the forward roadway and the perceived workload. Furthermore, when compared with driving without a secondary task, both voice interfaces did not significantly impact hazard anticipation, the frequency of long glances away from the forward roadway, or vehicle control. The multiple turn voice interface (B) significantly increased both the time it took drivers to complete the task and the workload. The implications for interface design and safety are discussed. PMID:20380920

  14. Time for a Change; Spirit's View on Sol 1843 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11973 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11973

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, full-circle view of the rover's surroundings during the 1,843rd Martian day, or sol, of Spirit's surface mission (March 10, 2009). South is in the middle. North is at both ends.

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The rover had driven 36 centimeters downhill earlier on Sol 1854, but had not been able to get free of ruts in soft material that had become an obstacle to getting around the northeastern corner of the low plateau called 'Home Plate.'

    The Sol 1854 drive, following two others in the preceding four sols that also achieved little progress in the soft ground, prompted the rover team to switch to a plan of getting around Home Plate counterclockwise, instead of clockwise. The drive direction in subsequent sols was westward past the northern edge of Home Plate.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  15. View Ahead After Spirit's Sol 1861 Drive (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11977 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11977

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images combined into this stereo, 210-degree view of the rover's surroundings during the 1,861st to 1,863rd Martian days, or sols, of Spirit's surface mission (March 28 to 30, 2009).

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The center of the scene is toward the south-southwest. East is on the left. West-northwest is on the right.

    The rover had driven 22.7 meters (74 feet) southwestward on Sol 1861 before beginning to take the frames in this view. The drive brought Spirit past the northwestern corner of Home Plate.

    In this view, the western edge of Home Plate is on the portion of the horizon farthest to the left. A mound in middle distance near the center of the view is called 'Tsiolkovsky' and is about 40 meters (about 130 feet) from the rover's position.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  16. Through Their Eyes: Lessons Learned Using Participatory Methods in Health Care Quality Improvement Projects

    PubMed Central

    Balbale, Salva N.; Locatelli, Sara M.; LaVela, Sherri L.

    2016-01-01

    In this methodological article, we examine participatory methods in-depth to demonstrate how these methods can be adopted for quality improvement (QI) projects in health care. We draw on existing literature and our QI initiatives in the Department of Veterans Affairs to discuss the application of photovoice and guided tours in QI efforts. We highlight lessons learned and several benefits of using participatory methods in this area. Using participatory methods, evaluators can engage patients, providers and other stakeholders as partners to enhance care. Participant involvement helps yield actionable data that can be translated into improved care practices. Use of these methods also helps generate key insights to inform improvements that truly resonate with stakeholders. Using participatory methods is a valuable strategy to harness participant engagement and drive improvements that address individual needs. In applying these innovative methodologies, evaluators can transcend traditional approaches to uniquely support evaluations and improvements in health care. PMID:26667882

  17. Commercial Truck Driver Health and Safety: Exploring Distracted Driving Performance and Self-Reported Driving Skill.

    PubMed

    Stavrinos, Despina; Heaton, Karen; Welburn, Sharon C; McManus, Benjamin; Griffin, Russell; Fine, Philip R

    2016-08-01

    Reducing distracters detrimental to commercial truck driving is a critical component of improving the safety performance of commercial drivers, and makes the highways safer for all drivers. This study used a driving simulator to examine effects of cell phone, texting, and email distractions as well as self-reported driver optimism bias on the driving performance of commercial truck drivers. Results revealed that more visually demanding tasks were related to poorer driving performance. However, the cell phone task resulted in less off-the-road eye glances. Drivers reporting being "very skilled" displayed poorer driving performance than those reporting being "skilled." Onboard communication devices provide a practical, yet visually and manually demanding, solution for connecting drivers and dispatchers. Trucking company policies should minimize interaction between dispatchers and drivers when the truck is in motion. Training facilities should integrate driving simulators into the instruction of commercial drivers, targeting over-confident drivers. © 2016 The Author(s).

  18. EGD discharge

    MedlinePlus

    ... It is not safe to drive or handle tools or equipment. You should also avoid making important work or legal decisions for the rest of the day, even if you believe your thinking is clear. Keep an eye on the site ...

  19. Object motion perception is shaped by the motor control mechanism of ocular pursuit.

    PubMed

    Schweigart, G; Mergner, T; Barnes, G R

    2003-02-01

    It is still a matter of debate whether the control of smooth pursuit eye movements involves an internal drive signal from object motion perception. We measured human target velocity and target position perceptions and compared them with the presumed pursuit control mechanism (model simulations). We presented normal subjects (Ns) and vestibular loss patients (Ps) with visual target motion in space. Concurrently, a visual background was presented, which was kept stationary or was moved with or against the target (five combinations). The motion stimuli consisted of smoothed ramp displacements with different dominant frequencies and peak velocities (0.05, 0.2, 0.8 Hz; 0.2-25.6 degrees /s). Subjects always pursued the target with their eyes. In a first experiment they gave verbal magnitude estimates of perceived target velocity in space and of self-motion in space. The target velocity estimates of both Ns and Ps tended to saturate at 0.8 Hz and with peak velocities >3 degrees /s. Below these ranges the velocity estimates showed a pronounced modulation in relation to the relative target-to-background motion ('background effect'; for example, 'background with'-motion decreased and 'against'-motion increased perceived target velocity). Pronounced only in Ps and not in Ns, there was an additional modulation in relation to the relative head-to-background motion, which co-varied with an illusion of self-motion in space (circular vection, CV) in Ps. In a second experiment, subjects performed retrospective reproduction of perceived target start and end positions with the same stimuli. Perceived end position was essentially veridical in both Ns and Ps (apart from a small constant offset). Reproduced start position showed an almost negligible background effect in Ns. In contrast, it showed a pronounced modulation in Ps, which again was related to CV. The results were compared with simulations of a model that we have recently presented for velocity control of eye pursuit. We found that the main features of target velocity perception (in terms of dynamics and modulation by background) closely correspond to those of the internal drive signal for target pursuit, compatible with the notion of a common source of both the perception and the drive signal. In contrast, the eye pursuit movement is almost free of the background effect. As an explanation, we postulate that the target-to-background component in the target pursuit drive signal largely neutralises the background-to-eye retinal slip signal (optokinetic reflex signal) that feeds into the eye premotor mechanism as a competitor of the target retinal slip signal. An extension of the model allowed us to simulate also the findings of the target position perception. It is assumed to be represented in a perceptual channel that is distinct from the velocity perception, building on an efference copy of the essentially accurate eye position. We hold that other visuomotor behaviour, such as target reaching with the hand, builds mainly on this target position percept and therefore is not contaminated by the background effect in the velocity percept. Generally, the coincidence of an erroneous velocity percept and an almost perfect eye pursuit movement during background motion is discussed as an instructive example of an action-perception dissociation. This dissociation cannot be taken to indicate that the two functions are internally represented in separate brain control systems, but rather reflects the intimate coupling between both functions.

  20. Driving behaviour in adults with attention deficit/hyperactivity disorder.

    PubMed

    Groom, Madeleine J; van Loon, Editha; Daley, David; Chapman, Peter; Hollis, Chris

    2015-07-28

    Little is known about the impact of cognitive impairments on driving in adults with ADHD. The present study compared the performance of adults with and without ADHD in a driving simulator on two different routes: an urban route which we hypothesised would exacerbate weak impulse control in ADHD and a motorway route, to challenge deficits in sustained attention. Adults with (n = 22, 16 males) and without (n = 21, 18 males) ADHD completed a simulated driving session while eye movement data were recorded simultaneously. Participants also completed the Manchester Driving Behaviour Questionnaire (DBQ) and the Conners Adult ADHD Rating Scale (CAARS). Measures of driving performance included average speed, proportion distance travelled over speed limit (speeding) and lane deviation. These variables and the eye movement measures (spread of fixations, mean fixation duration) were compared between groups and routes. Also, driving behaviours, including responses to programmed events, were categorised and the frequencies within categories were compared between groups. Finally, speech analysis was performed to compare emotional verbal expressions during driving between groups. ADHD participants reported significantly more Violations and Lapses on the DBQ than control participants and significantly more accidents. Average speed and speeding were also higher but did not interact with route type. ADHD participants showed poorer vehicle control, greater levels of frustration with other road users (including greater frequencies of negative comments) and a trend for less safe driving when changing lanes/overtaking on the motorway. These effects were predicted by hyperactive/impulsive CAARS scores. They were also more likely to cause a crash/near miss when an event occurred on the urban route. The results suggest that difficulty regulating and controlling impulsive behavior, reflected in speeding, frustration with other road users, less safety when changing lanes on the motorway and a greater likelihood of an accident following an unexpected event, underlie impaired driving in ADHD. Hyperactivity/impulsivity symptoms correlated with these indices. Deficits in sustained attention seemed to play a lesser role in this particular study, although further research is needed to determine whether effects on attention emerge over longer periods of time and/or are influenced by the novelty of the simulator environment.

  1. Glaucomatous Retinal Nerve Fiber Layer Thickness Loss is associated with Slower Reaction Times under a Divided Attention Task

    PubMed Central

    Tatham, Andrew J.; Boer, Erwin R.; Rosen, Peter N.; Penna, Mauro Della; Meira-Freitas, Daniel; Weinreb, Robert N.; Zangwill, Linda M.; Medeiros, Felipe A.

    2014-01-01

    Purpose To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving. Design Cross-sectional observational study. Methods Setting Hamilton Glaucoma Center, University of California San Diego. Patient Population 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls. Observation Procedure Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measured retinal nerve fiber (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire. Main outcome measures Reaction times to the driving simulator divided attention task. Results The mean reaction times to the low contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls respectively during curve negotiation (P <0.001), and 1.19 s and 0.77 s (P = 0.025) respectively during car following. There was a non-linear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability and central driving task performance. Conclusions Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving. PMID:25068641

  2. 38 CFR 4.78 - Muscle function.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Evaluation of muscle function. (1) An evaluation for diplopia will be assigned to only one eye. When a... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected...

  3. 38 CFR 4.78 - Muscle function.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Evaluation of muscle function. (1) An evaluation for diplopia will be assigned to only one eye. When a... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected... visual acuity for the poorer eye (or the affected eye, if disability of only one eye is service-connected...

  4. Driver distraction : eye glance analysis and conversation workload : [research brief].

    DOT National Transportation Integrated Search

    2015-11-01

    The objective of this project was to: : Assess the risk of performing a secondary task : while driving a commercial motor vehicle (CMV). : Better understand the relationship of conversation : workload and visual distraction during mobile : ph...

  5. What's skill got to do with it? Vehicle automation and driver mental workload.

    PubMed

    Young, M S; Stanton, N A

    2007-08-01

    Previous research has found that vehicle automation systems can reduce driver mental workload, with implications for attentional resources that can be detrimental to performance. The present paper considers how the development of automaticity within the driving task may influence performance in underload situations. Driver skill and vehicle automation were manipulated in a driving simulator, with four levels of each variable. Mental workload was assessed using a secondary task measure and eye movements were recorded to infer attentional capacity. The effects of automation on driver mental workload were quite robust across skill levels, but the most intriguing findings were from the eye movement data. It was found that, with little exception, attentional capacity and mental workload were directly related at all levels of driver skill, consistent with earlier studies. The results are discussed with reference to applied theories of cognition and the design of automation.

  6. A Burst-Based “Hebbian” Learning Rule at Retinogeniculate Synapses Links Retinal Waves to Activity-Dependent Refinement

    PubMed Central

    Butts, Daniel A; Kanold, Patrick O; Shatz, Carla J

    2007-01-01

    Patterned spontaneous activity in the developing retina is necessary to drive synaptic refinement in the lateral geniculate nucleus (LGN). Using perforated patch recordings from neurons in LGN slices during the period of eye segregation, we examine how such burst-based activity can instruct this refinement. Retinogeniculate synapses have a novel learning rule that depends on the latencies between pre- and postsynaptic bursts on the order of one second: coincident bursts produce long-lasting synaptic enhancement, whereas non-overlapping bursts produce mild synaptic weakening. It is consistent with “Hebbian” development thought to exist at this synapse, and we demonstrate computationally that such a rule can robustly use retinal waves to drive eye segregation and retinotopic refinement. Thus, by measuring plasticity induced by natural activity patterns, synaptic learning rules can be linked directly to their larger role in instructing the patterning of neural connectivity. PMID:17341130

  7. Objective assessment of the effects of texting while driving: a simulator study.

    PubMed

    Bendak, Salaheddine

    2015-01-01

    Recent advances in electronic communication technology led to many drivers opting to send and receive text messages while driving. This, inevitably, has a potential to distract drivers, impair driving performance and lead to crashes. This study aims to assess the risk involved in texting while driving through assessing the distraction caused and determining the change in key driving performance indicators. Twenty-one paid young male volunteers were recruited to participate in this study. Each participant drove a driving simulator on four different scenarios involving driving while texting and without texting on highways and town roads. Results showed that texting while driving led, on average, to five times more crashes than driving without texting. Due to distraction also, participants unnecessarily crossed lane boundaries and road boundaries more often while texting as compared to driving without texting. Moreover, distraction due to texting led to participants deviating their eyes off the road while texting 15 times per session, on average, more than without texting. Results demonstrated a high-risk level of distraction and clear impairment in drivers' ability to drive safely due to texting. Based on the results, practical recommendations to combat this phenomenon are given.

  8. Pax2 regulates a fadd-dependent molecular switch that drives tissue fusion during eye development.

    PubMed

    Viringipurampeer, Ishaq A; Ferreira, Todd; DeMaria, Shannon; Yoon, Jookyung J; Shan, Xianghong; Moosajee, Mariya; Gregory-Evans, Kevin; Ngai, John; Gregory-Evans, Cheryl Y

    2012-05-15

    Tissue fusion is an essential morphogenetic mechanism in development, playing a fundamental role in developing neural tube, palate and the optic fissure. Disruption of genes associated with the tissue fusion can lead to congenital malformations, such as spina bifida, cleft lip/palate and ocular coloboma. For instance, the Pax2 transcription factor is required for optic fissure closure, although the mechanism of Pax2 action leading to tissue fusion remains elusive. This lack of information defining how transcription factors drive tissue morphogenesis at the cellular level is hampering new treatments options. Through loss- and gain-of-function analysis, we now establish that pax2 in combination with vax2 directly regulate the fas-associated death domain (fadd) gene. In the presence of fadd, cell proliferation is restricted in the developing eye through a caspase-dependent pathway. However, the loss of fadd results in a proliferation defect and concomitant activation of the necroptosis pathway through RIP1/RIP3 activity, leading to an abnormal open fissure. Inhibition of RIP1 with the small molecule drug necrostatin-1 rescues the pax2 eye fusion defect, thereby overcoming the underlying genetic defect. Thus, fadd has an essential physiological function in protecting the developing optic fissure neuroepithelium from RIP3-dependent necroptosis. This study demonstrates the molecular hierarchies that regulate a cellular switch between proliferation and the apoptotic and necroptotic cell death pathways, which in combination drive tissue morphogenesis. Furthermore, our data suggest that future therapeutic strategies may be based on small molecule drugs that can bypass the gene defects causing common congenital tissue fusion defects.

  9. Visual acuity of commercial motor drivers in Ogun State of Nigeria.

    PubMed

    Onabolu, O O; Bodunde, O T; Otulana, T O; Ajibode, H A; Awodein, O G; Onadipe, O J; Jagun, O A

    2012-12-01

    To objectively assess the visual acuity of commercial motor drivers (CMD) in 3 Local Government Areas (LGA) of Ogun State of Nigeria in order to determine their eligibility to drive. The visual acuities of CMDs in 3 LGAS of Ogun state in Nigeria (selected using a multistage sampling technique) were tested with Snellens acuity charts and the eyes examined with bright pen torches and ophthamoscopes. Visual acuity 6/12 or better in the worse eye was taken as adequate to obtain a driving license. The drivers with worse visual acuities were further examined to find the cause of decreased vision. The visual acuities of 524 drivers were determined and analyzed. Their ages ranged from 19-66 years with a mean of 46.8 ±7.2 years. Two hundred and twenty (41.9%) of the drivers were between 40 and 49 years old. Four hundred and four (77.1%) did not have any form of eye test prior to this study. Four hundred and sixty three drivers (88.4%) were eligible to drive while 61 drivers (11.6%) were not eligible. Decreased visual acuity was caused by refractive error in 22(36.1%), cataract in 19(31.2%), glaucoma in 12(19.7%), corneal scar in 5(8.2%) and posterior segment lesions in 3(4.9%). Objective assessment of vision should be an essential component of licensure. Middle aged and elderly drivers are prone to age related ocular diseases and require reassessment of visual status every 3 years when licenses are renewed.

  10. Identification of real-time diagnostic measures of visual distraction with an automatic eye-tracking system.

    PubMed

    Zhang, Harry; Smith, Matthew R H; Witt, Gerald J

    2006-01-01

    This study was conducted to identify eye glance measures that are diagnostic of visual distraction. Visual distraction degrades performance, but real-time diagnostic measures have not been identified. In a driving simulator, 14 participants responded to a lead vehicle braking at -2 or -2.7 m/s2 periodically while reading a varying number of words (6-15 words every 13 s) on peripheral displays (with diagonal eccentricities of 24 degrees, 43 degrees, and 75 degrees). As the number of words and display eccentricity increased, total glance duration and reaction time increased and driving performance suffered. Correlation coefficients between several glance measures and reaction time or performance variables were reliably high, indicating that these glance measures are diagnostic of visual distraction. It is predicted that for every 25% increase in total glance duration, reaction time is increased by 0.39 s and standard deviation of lane position is increased by 0.06 m. Potential applications of this research include assessing visual distraction in real time, delivering advisories to distracted drivers to reorient their attention to driving, and using distraction information to adapt forward collision and lane departure warning systems to enhance system effectiveness.

  11. Improving Night Time Driving Safety Using Vision-Based Classification Techniques.

    PubMed

    Chien, Jong-Chih; Chen, Yong-Sheng; Lee, Jiann-Der

    2017-09-24

    The risks involved in nighttime driving include drowsy drivers and dangerous vehicles. Prominent among the more dangerous vehicles around at night are the larger vehicles which are usually moving faster at night on a highway. In addition, the risk level of driving around larger vehicles rises significantly when the driver's attention becomes distracted, even for a short period of time. For the purpose of alerting the driver and elevating his or her safety, in this paper we propose two components for any modern vision-based Advanced Drivers Assistance System (ADAS). These two components work separately for the single purpose of alerting the driver in dangerous situations. The purpose of the first component is to ascertain that the driver would be in a sufficiently wakeful state to receive and process warnings; this is the driver drowsiness detection component. The driver drowsiness detection component uses infrared images of the driver to analyze his eyes' movements using a MSR plus a simple heuristic. This component issues alerts to the driver when the driver's eyes show distraction and are closed for a longer than usual duration. Experimental results show that this component can detect closed eyes with an accuracy of 94.26% on average, which is comparable to previous results using more sophisticated methods. The purpose of the second component is to alert the driver when the driver's vehicle is moving around larger vehicles at dusk or night time. The large vehicle detection component accepts images from a regular video driving recorder as input. A bi-level system of classifiers, which included a novel MSR-enhanced KAZE-base Bag-of-Features classifier, is proposed to avoid false negatives. In both components, we propose an improved version of the Multi-Scale Retinex (MSR) algorithm to augment the contrast of the input. Several experiments were performed to test the effects of the MSR and each classifier, and the results are presented in experimental results section of this paper.

  12. Test Rover Sinks into Prepared Soil

    NASA Image and Video Library

    2009-06-30

    While a test rover rolls off a plywood surface into a prepared bed of soft soil, rover team members Colette Lohr left and Kim Lichtenberg center eye the wheels digging into the soil and Paolo Bellutta enters the next driving command.

  13. 78 FR 63302 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    .... Ferris Mr. Ferris, 70, has had complete loss of vision in his right eye since 1991. The visual acuity in... sufficient vision to perform his driving tasks to operate a commercial vehicle.'' Mr. Ferris reported that he...

  14. BMP signaling protects telencephalic fate by repressing eye identity and its Cxcr4-dependent morphogenesis.

    PubMed

    Bielen, Holger; Houart, Corinne

    2012-10-16

    Depletion of Wnt signaling is a major requirement for the induction of the anterior prosencephalon. However, the molecular events driving the differential regionalization of this area into eye-field and telencephalon fates are still unknown. Here we show that the BMP pathway is active in the anterior neural ectoderm during late blastula to early gastrula stage in zebrafish. Bmp2b mutants and mosaic loss-of-function experiments reveal that BMP acts as a repressor of eye-field fate through inhibition of its key transcription factor Rx3, thereby protecting the future telencephalon from acquiring eye identity. This BMP-driven mechanism initiates the establishment of the telencephalon prior to the involvement of Wnt antagonists from the anterior neural border. Furthermore, we demonstrate that Rx3 and BMP are respectively required to maintain and restrict the chemokine receptor cxcr4a, which in turn contributes to the morphogenetic separation of eye-field and telencephalic cells during early neurulation. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A Two-Year Study of Δ 9 Tetrahydrocannabinol Concentrations in Drivers; Part 2: Physiological Signs on Drug Recognition Expert (DRE) and non-DRE Examinations,.

    PubMed

    Declues, Kari; Perez, Shelli; Figueroa, Ariana

    2018-03-01

    Whole blood samples were examined for ∆ 9 -Tetrahydrocannabinol (THC) over 2 years in drivers suspected of driving under the influence. Part one of the study examined the link between [THC] and performance on field sobriety tests. This portion examined objective signs, eye examinations and physiological indicators; and their relationship to the presence of THC. Several objective signs were excellent indicators of the presence of THC: red eyes (94%), droopy eyelids (85.6%), affected speech (87.6%), tongue coating (96.2%), and odor of marijuana (82.4%). About 63.6% of THC positive subjects had dialted pupils (room light). THC positive subjects had either rebound dilation or hippus in 88.8% of cases. Pulse and blood pressure (BP) were evaluated to determine any correlation with [THC]. An increased pulse rate correlated well to the presence of THC (88.5%), but not [THC]. BP did not correlate to [THC] and was also a poor indicator of THC in the blood (50% high). © 2017 American Academy of Forensic Sciences.

  16. A Review of Hazard Anticipation Training Programs for Young Drivers.

    PubMed

    McDonald, Catherine C; Goodwin, Arthur H; Pradhan, Anuj K; Romoser, Matthew R E; Williams, Allan F

    2015-07-01

    Poor hazard anticipation skills are a risk factor associated with high motor vehicle crash rates of young drivers. A number of programs have been developed to improve these skills. The purpose of this review was to assess the empirical literature on hazard anticipation training for young drivers. Studies were included if they (1) included an assessment of hazard anticipation training outcomes; (2) were published between January 1, 1980 and December 31, 2013 in an English language peer-reviewed journal or conference proceeding; and (3) included at least one group that uniquely comprised a cohort of participants aged <21 years. Nineteen studies met inclusion criteria. Studies used a variety of training methods including interactive computer programs, videos, simulation, commentary driving, or a combination of approaches. Training effects were predominantly measured through computer-based testing and driving simulation with eye tracking. Four studies included an on-road evaluation. Most studies evaluated short-term outcomes (immediate or few days). In all studies, young drivers showed improvement in selected hazard anticipation outcomes but none investigated crash effects. Although there is promise in existing programs, future research should include long-term follow-up, evaluate crash outcomes, and assess the optimal timing of hazard anticipation training taking into account the age and experience level of young drivers. Copyright © 2015 Society for Adolescent Health and Medicine. All rights reserved.

  17. International vision requirements for driver licensing and disability pensions: using a milestone approach in characterization of progressive eye disease

    PubMed Central

    Bron, Alain M; Viswanathan, Ananth C; Thelen, Ulrich; de Natale, Renato; Ferreras, Antonio; Gundgaard, Jens; Schwartz, Gail; Buchholz, Patricia

    2010-01-01

    Objective Low vision that causes forfeiture of driver’s licenses and collection of disability pension benefits can lead to negative psychosocial and economic consequences. The purpose of this study was to review the requirements for holding a driver’s license and rules for obtaining a disability pension due to low vision. Results highlight the possibility of using a milestone approach to describe progressive eye disease. Methods Government and research reports, websites, and journal articles were evaluated to review rules and requirements in Germany, Spain, Italy, France, the UK, and the US. Results Visual acuity limits are present in all driver’s license regulations. In most countries, the visual acuity limit is 0.5. Visual field limits are included in some driver’s license regulations. In Europe, binocular visual field requirements typically follow the European Union standard of ≥120°. In the US, the visual field requirements are typically between 110° and 140°. Some countries distinguish between being partially sighted and blind in the definition of legal blindness, and in others there is only one limit. Conclusions Loss of driving privileges could be used as a milestone to monitor progressive eye disease. Forfeiture could be standardized as a best-corrected visual acuity of <0.5 or visual field of <120°, which is consistent in most countries. However, requirements to receive disability pensions were too variable to standardize as milestones in progressive eye disease. Implementation of the World Health Organization criteria for low vision and blindness would help to establish better comparability between countries. PMID:21179219

  18. Experimental research on safety impacts of the inside shoulder based on driving simulation.

    PubMed

    Zhao, Xiaohua; Ding, Han; Wu, Yiping; Ma, Jianming; Zhong, Liande

    2015-03-01

    Statistical data shows that single-vehicle crashes account for half of all traffic crashes on expressways in China, and previous research has indicated that main contributing factors were related to whether and how the inside shoulder was paved. The inside shoulder provides space for drivers to make evasive maneuvers and accommodate driver errors. However, lower-cost construction solutions in China have resulted in the design of numerous urban expressway segments that lack inside shoulders. This paper has two objectives. The first is to reveal the safety impacts of inside shoulders on urban expressways by driving simulator experiment. The second objective is to propose optimal range and recommended value of inside shoulder width for designing inside shoulders of urban expressways. The empirical data, including subjects' eye movement data, heart rate (HR) and the lateral position of vehicles, were collected in a driving simulator. The data were analyzed to evaluate the safety impacts of the inside shoulder. The results have revealed that the inside shoulder has an impact on drivers' visual perception, behaviors, and psychology; in particular, it has a significant effect on vehicle operations. In addition, this paper recommends the desired and optimal inside shoulder widths for eight-lane, two-way divided expressways. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Central Connections of the Lacrimal Functional Unit.

    PubMed

    Willshire, Catherine; Buckley, Roger J; Bron, Anthony J

    2017-08-01

    To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia. A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were as follows: 1) bilateral saline (control), 2) unilateral anesthesia (ipsilateral anesthetic; contralateral saline), and 3) bilateral anesthesia. There was no difference in between-eye wetting lengths in the saline control eyes (P = 0.394) or the bilaterally anesthetized eyes (P = 0.171). The wetting length was reduced in both eyes after bilateral anesthesia compared with saline controls (P = 0.001; P ≤ 0.0005). After unilateral anesthesia, the wetting length was reduced in the anesthetized eye compared with its saline control by 51.4% (P ≤ 0.0005) and compared with its fellow, unanesthetized eye (P = 0.005). The fellow eye value was also reduced compared with its saline control (P = 0.06). The wetting length was reduced by topical anesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanesthetized fellow eye, the reduction compared with its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal fellow eye, in cases of unilateral corneal anesthesia.

  20. Amygdala lesions in rhesus macaques decrease attention to threat

    PubMed Central

    Dal Monte, Olga; Costa, Vincent D.; Noble, Pamela L.; Murray, Elisabeth A.; Averbeck, Bruno B.

    2015-01-01

    Evidence from animal and human studies has suggested that the amygdala plays a role in detecting threat and in directing attention to the eyes. Nevertheless, there has been no systematic investigation of whether the amygdala specifically facilitates attention to the eyes or whether other features can also drive attention via amygdala processing. The goal of the present study was to examine the effects of amygdala lesions in rhesus monkeys on attentional capture by specific facial features, as well as gaze patterns and changes in pupil dilation during free viewing. Here we show reduced attentional capture by threat stimuli, specifically the mouth, and reduced exploration of the eyes in free viewing in monkeys with amygdala lesions. Our findings support a role for the amygdala in detecting threat signals and in directing attention to the eye region of faces when freely viewing different expressions. PMID:26658670

  1. Epigenetic Treatment of Neurodegenerative Ophthalmic Disorders: An Eye Toward the Future

    PubMed Central

    Moos, Walter H.; Faller, Douglas V.; Glavas, Ioannis P.; Harpp, David N.; Irwin, Michael H.; Kanara, Iphigenia; Pinkert, Carl A.; Powers, Whitney R.; Steliou, Kosta; Vavvas, Demetrios G.; Kodukula, Krishna

    2017-01-01

    Abstract Eye disease is one of the primary medical conditions that requires attention and therapeutic intervention in ageing populations worldwide. Further, the global burden of diabetes and obesity, along with heart disease, all lead to secondary manifestations of ophthalmic distress. Therefore, there is increased interest in developing innovative new approaches that target various mechanisms and sequelae driving conditions that result in adverse vision. The research challenge is even greater given that the terrain of eye diseases is difficult to landscape into a single therapeutic theme. This report addresses the burden of eye disease due to mitochondrial dysfunction, including antioxidant, autophagic, epigenetic, mitophagic, and other cellular processes that modulate the biomedical end result. In this light, we single out lipoic acid as a potent known natural activator of these pathways, along with alternative and potentially more effective conjugates, which together harness the necessary potency, specificity, and biodistribution parameters required for improved therapeutic outcomes. PMID:29291141

  2. Epigenetic Treatment of Neurodegenerative Ophthalmic Disorders: An Eye Toward the Future.

    PubMed

    Moos, Walter H; Faller, Douglas V; Glavas, Ioannis P; Harpp, David N; Irwin, Michael H; Kanara, Iphigenia; Pinkert, Carl A; Powers, Whitney R; Steliou, Kosta; Vavvas, Demetrios G; Kodukula, Krishna

    2017-01-01

    Eye disease is one of the primary medical conditions that requires attention and therapeutic intervention in ageing populations worldwide. Further, the global burden of diabetes and obesity, along with heart disease, all lead to secondary manifestations of ophthalmic distress. Therefore, there is increased interest in developing innovative new approaches that target various mechanisms and sequelae driving conditions that result in adverse vision. The research challenge is even greater given that the terrain of eye diseases is difficult to landscape into a single therapeutic theme. This report addresses the burden of eye disease due to mitochondrial dysfunction, including antioxidant, autophagic, epigenetic, mitophagic, and other cellular processes that modulate the biomedical end result. In this light, we single out lipoic acid as a potent known natural activator of these pathways, along with alternative and potentially more effective conjugates, which together harness the necessary potency, specificity, and biodistribution parameters required for improved therapeutic outcomes.

  3. A Macintosh-Based Scientific Images Video Analysis System

    NASA Technical Reports Server (NTRS)

    Groleau, Nicolas; Friedland, Peter (Technical Monitor)

    1994-01-01

    A set of experiments was designed at MIT's Man-Vehicle Laboratory in order to evaluate the effects of zero gravity on the human orientation system. During many of these experiments, the movements of the eyes are recorded on high quality video cassettes. The images must be analyzed off-line to calculate the position of the eyes at every moment in time. To this aim, I have implemented a simple inexpensive computerized system which measures the angle of rotation of the eye from digitized video images. The system is implemented on a desktop Macintosh computer, processes one play-back frame per second and exhibits adequate levels of accuracy and precision. The system uses LabVIEW, a digital output board, and a video input board to control a VCR, digitize video images, analyze them, and provide a user friendly interface for the various phases of the process. The system uses the Concept Vi LabVIEW library (Graftek's Image, Meudon la Foret, France) for image grabbing and displaying as well as translation to and from LabVIEW arrays. Graftek's software layer drives an Image Grabber board from Neotech (Eastleigh, United Kingdom). A Colour Adapter box from Neotech provides adequate video signal synchronization. The system also requires a LabVIEW driven digital output board (MacADIOS II from GW Instruments, Cambridge, MA) controlling a slightly modified VCR remote control used mainly to advance the video tape frame by frame.

  4. Visual problems in young adults due to computer use.

    PubMed

    Moschos, M M; Chatziralli, I P; Siasou, G; Papazisis, L

    2012-04-01

    Computer use can cause visual problems. The purpose of our study was to evaluate visual problems due to computer use in young adults. Participants in our study were 87 adults, 48 male and 39 female, mean aged 31.3 years old (SD 7.6). All the participants completed a questionnaire regarding visual problems detected after computer use. The mean daily use of computers was 3.2 hours (SD 2.7). 65.5 % of the participants complained for dry eye, mainly after more than 2.5 hours of computer use. 32 persons (36.8 %) had a foreign body sensation in their eyes, while 15 participants (17.2 %) complained for blurred vision which caused difficulties in driving, after 3.25 hours of continuous computer use. 10.3 % of the participants sought medical advice for their problem. There was a statistically significant correlation between the frequency of visual problems and the duration of computer use (p = 0.021). 79.3 % of the participants use artificial tears during or after long use of computers, so as not to feel any ocular discomfort. The main symptom after computer use in young adults was dry eye. All visual problems associated with the duration of computer use. Artificial tears play an important role in the treatment of ocular discomfort after computer use. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia

    NASA Astrophysics Data System (ADS)

    Lee, Michael S. Y.; Jago, James B.; García-Bellido, Diego C.; Edgecombe, Gregory D.; Gehling, James G.; Paterson, John R.

    2011-06-01

    Despite the status of the eye as an ``organ of extreme perfection'', theory suggests that complex eyes can evolve very rapidly. The fossil record has, until now, been inadequate in providing insight into the early evolution of eyes during the initial radiation of many animal groups known as the Cambrian explosion. This is surprising because Cambrian Burgess-Shale-type deposits are replete with exquisitely preserved animals, especially arthropods, that possess eyes. However, with the exception of biomineralized trilobite eyes, virtually nothing is known about the details of their optical design. Here we report exceptionally preserved fossil eyes from the Early Cambrian (~515 million years ago) Emu Bay Shale of South Australia, revealing that some of the earliest arthropods possessed highly advanced compound eyes, each with over 3,000 large ommatidial lenses and a specialized `bright zone'. These are the oldest non-biomineralized eyes known in such detail, with preservation quality exceeding that found in the Burgess Shale and Chengjiang deposits. Non-biomineralized eyes of similar complexity are otherwise unknown until about 85 million years later. The arrangement and size of the lenses indicate that these eyes belonged to an active predator that was capable of seeing in low light. The eyes are more complex than those known from contemporaneous trilobites and are as advanced as those of many living forms. They provide further evidence that the Cambrian explosion involved rapid innovation in fine-scale anatomy as well as gross morphology, and are consistent with the concept that the development of advanced vision helped to drive this great evolutionary event.

  6. Cognitive Load Measurement in a Virtual Reality-based Driving System for Autism Intervention

    PubMed Central

    Zhang, Lian; Wade, Joshua; Bian, Dayi; Fan, Jing; Swanson, Amy; Weitlauf, Amy; Warren, Zachary; Sarkar, Nilanjan

    2016-01-01

    Autism Spectrum Disorder (ASD) is a highly prevalent neurodevelopmental disorder with enormous individual and social cost. In this paper, a novel virtual reality (VR)-based driving system was introduced to teach driving skills to adolescents with ASD. This driving system is capable of gathering eye gaze, electroencephalography, and peripheral physiology data in addition to driving performance data. The objective of this paper is to fuse multimodal information to measure cognitive load during driving such that driving tasks can be individualized for optimal skill learning. Individualization of ASD intervention is an important criterion due to the spectrum nature of the disorder. Twenty adolescents with ASD participated in our study and the data collected were used for systematic feature extraction and classification of cognitive loads based on five well-known machine learning methods. Subsequently, three information fusion schemes—feature level fusion, decision level fusion and hybrid level fusion—were explored. Results indicate that multimodal information fusion can be used to measure cognitive load with high accuracy. Such a mechanism is essential since it will allow individualization of driving skill training based on cognitive load, which will facilitate acceptance of this driving system for clinical use and eventual commercialization. PMID:28966730

  7. Cognitive Load Measurement in a Virtual Reality-based Driving System for Autism Intervention.

    PubMed

    Zhang, Lian; Wade, Joshua; Bian, Dayi; Fan, Jing; Swanson, Amy; Weitlauf, Amy; Warren, Zachary; Sarkar, Nilanjan

    2017-01-01

    Autism Spectrum Disorder (ASD) is a highly prevalent neurodevelopmental disorder with enormous individual and social cost. In this paper, a novel virtual reality (VR)-based driving system was introduced to teach driving skills to adolescents with ASD. This driving system is capable of gathering eye gaze, electroencephalography, and peripheral physiology data in addition to driving performance data. The objective of this paper is to fuse multimodal information to measure cognitive load during driving such that driving tasks can be individualized for optimal skill learning. Individualization of ASD intervention is an important criterion due to the spectrum nature of the disorder. Twenty adolescents with ASD participated in our study and the data collected were used for systematic feature extraction and classification of cognitive loads based on five well-known machine learning methods. Subsequently, three information fusion schemes-feature level fusion, decision level fusion and hybrid level fusion-were explored. Results indicate that multimodal information fusion can be used to measure cognitive load with high accuracy. Such a mechanism is essential since it will allow individualization of driving skill training based on cognitive load, which will facilitate acceptance of this driving system for clinical use and eventual commercialization.

  8. The Effect of Secondary Task Engagement on Adolescents' Driving Performance and Crash Risk.

    PubMed

    Klauer, Sheila G; Ehsani, Johnathon P; McGehee, Daniel V; Manser, Michael

    2015-07-01

    The purpose of this review was to synthesize the evidence of the effects of secondary task engagement on novice adolescent's driving performance and crash risk. Searches of multiple databases were conducted using search terms related to secondary task engagement and teenage drivers. Articles were selected for inclusion if they were: written in English, an empirical study assessing the impact of secondary task engagement on driving, and included study participants who were licensed drivers between the ages of 14 and 17 years (if research was conducted in the United States) or within 18 months licensure in other countries. Thirty-eight abstracts were reviewed. Fifteen studies met the inclusion criteria. Most studies examined the effects of electronic device use as the secondary task. Effects were assessed using crash databases, simulator, instrumented vehicle, and naturalistic driving studies. Texting resulted in increased lane deviations and eyes off road time in simulated driving, whereas talking on a cell phone had little effect. Naturalistic studies, which use vehicle instrumentation to measure actual driving, found secondary tasks that required drivers to look away from the forward roadway also increased the risk of crashes and near-crashes for young novice drivers, whereas tasks that did not require eyes to be off the forward roadway (e.g., talking on cell phone) had no effect on crash risk. Methodological differences in the definition and measurement of driving performance make it difficult to directly compare findings, even among the limited number of studies conducted. Despite this, results suggest that secondary tasks degrade driving performance and increase risk only when they require drivers to look away from the forward roadway. Future research needs to focus more explicitly on the ways in which secondary task engagement influences drivers' behavior (e.g., interfering with information acquisition or manual control of the vehicle). This, along with the use of standard measures across studies, would build a more useful body of literature on this topic. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  9. Developing an Item Bank to Measure Quality of Life in Individuals With Glaucoma, and the Results of the Interview With Patients: The Effect of Visual Function, Visual Field Progression Rate, Medical, and Surgical Treatments on Quality of Life.

    PubMed

    Matsuura, Masato; Hirasawa, Kazunori; Hirasawa, Hiroyo; Yanagisawa, Mieko; Murata, Hiroshi; Mayama, Chihiro; Asaoka, Ryo

    2017-02-01

    To construct a new item bank to measure quality of life (QOL) in glaucoma patients and to evaluate glaucoma patients' QOL using the item bank. An item bank of questions was generated through a literature review of QOL instruments useful for glaucoma patients. Using this item bank, a cognitive survey was performed on 203 patients with glaucoma (112 males and 91 females, 61.9±11.9 y old; mean±SD). The results were then analyzed using the Rasch analysis, and the Rasch-derived disability scores were predicted using linear modelling and the following clinical parameters: age, mean total deviation (mTD) in superior and inferior visual field (mTDsup/mTDinf), mTD progression rate, better visual acuity, worse visual acuity, number of eye drops administered per day, number of trabeculectomy procedures experienced in both eyes. A total of 23 questionnaires of QOL in glaucoma patients were identified resulting in an item bank of 187 questions related to the following tasks: reading/writing, walking, going out, eating and driving (direct disability) as well as questions concerned with worry/anxiety, social participation, and physical symptoms (indirect disability). In the optimal model for direct disability, age and mTDinf were identified as significant predictors, whereas number of eye drops administered per day and number of trabeculectomy experienced were included in the optimal model for indirect disability. A new item bank to measure QOL in glaucoma patients was developed and evaluated. Age and mTDinf were found to be related to direct disability while medical and surgical treatments were related to indirect disability.

  10. Safety-critical event risk associated with cell phone tasks as measured in naturalistic driving studies: A systematic review and meta-analysis.

    PubMed

    Simmons, Sarah M; Hicks, Anne; Caird, Jeff K

    2016-02-01

    A systematic review and meta-analysis of naturalistic driving studies involving estimates of safety-critical event risk associated with handheld device use while driving is described. Fifty-seven studies identified from targeted databases, journals and websites were reviewed in depth, and six were ultimately included. These six studies, published between 2006 and 2014, encompass seven sets of naturalistic driver data and describe original research that utilized naturalistic methods to assess the effects of distracting behaviors. Four studies involved non-commercial drivers of light vehicles and two studies involved commercial drivers of trucks and buses. Odds ratios quantifying safety-critical event (SCE) risk associated with talking, dialing, locating or answering, and texting or browsing were extracted. Stratified meta-analysis of pooled odds ratios was used to estimate SCE risk by distraction type; meta-regression was used to test for sources of heterogeneity. The results indicate that tasks that require drivers to take their eyes off the road, such as dialing, locating a phone and texting, increase SCE risk to a greater extent than tasks that do not require eyes off the road such as talking. Although talking on a handheld device did not increase SCE risk, further research is required to determine whether it indirectly influences SCE risk (e.g., by encouraging other cell phone activities). In addition, a number of study biases and quality issues of naturalistic driving studies are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. The effects of momentary visual disruption on hazard anticipation and awareness in driving.

    PubMed

    Borowsky, Avinoam; Horrey, William J; Liang, Yulan; Garabet, Angela; Simmons, Lucinda; Fisher, Donald L

    2015-01-01

    Driver distraction is known to increase crash risk, especially when a driver glances inside the vehicle for especially long periods of time. Though it is clear that such glances increase the risk for the driver when looking inside the vehicle, it is less clear how these glances disrupt the ongoing processing of information outside the vehicle once the driver's eyes return to the road. The present study was aimed at exploring the effect of in-vehicle glances on the top-down processes that guide the detection and monitoring of hazards on the forward roadway. Using a driving simulator, 12 participants were monitored with an eye-tracking system while they navigated various hazardous scenarios. Six participants were momentarily interrupted by a visual secondary task (simulating a glance inside the vehicle) prior to the occurrence of a potential hazard and 6 were not. Eye movement analyses showed that interrupted drivers often failed to continue scanning for a potential hazard when their forward view reappeared, especially when the potential threat could not easily be localized. Additionally, drivers' self-appraisal of workload and performance of the driving task indicated that, contrary to what one might expect, drivers in the interruption condition reported workload levels lower than and performance equal to drivers in the no interruption condition. Drivers who are momentarily disrupted even for a brief duration are at risk of missing important information when they return their gaze to the forward roadway. In addition, because they are not aware of missing this information they are likely to continue engaging in in-vehicle tasks even though they are demonstrably unsafe. The implications for safety, calibration, and targeted remediation are discussed.

  12. Stage of visual field loss and age at diagnosis in 1988 patients with different glaucomas: implications for glaucoma screening and driving ability.

    PubMed

    Gramer, Gwendolyn; Gramer, Eugen

    2018-04-01

    To compare stage of visual field loss (VFL) and age at diagnosis between patients with different types of glaucoma with regard to glaucoma screening and driving ability. In a cross-sectional study of 1988 consecutive patients with different types of glaucoma VFL at diagnosis and age at diagnosis were assessed. Patients with binocular advanced or severe VFL were classified unable, patients with no VFL in one eye and VFL I-V (Aulhorn classification) in the other eye able, all other constellations questionably able to drive. There were significant differences in age at diagnosis between different glaucomas and between patients with different stages of VFL at diagnosis. Age-related assessment of VFL at diagnosis in normal tension glaucoma (NTG) compared to primary open-angle glaucoma (POAG) showed that NTG is not a disease of the elderly but a disease with late diagnosis at severe VFL. In POAG a solely age-related glaucoma screening, e.g. from the age of 50 years, does not sufficiently lead to diagnosis at an early stage of the disease. In POAG solely based on binocular VFL 11.5% of patients were judged unable, 29.2% questionably able to drive, in NTG 19.6%/43.1%, pigmentary glaucoma 16%/22%, pseudoexfoliation glaucoma 9.1%/16.7%, and in primary angle-closure glaucoma 14.6%/30%. Depending on type of glaucoma more than 50% of patients require counselling regarding safe driving as part of clinical care. A disease-specific, age-related perimetric examination considering additional risk factors like family history of glaucoma is essential for early detection of glaucoma and road safety.

  13. Through Their Eyes: Lessons Learned Using Participatory Methods in Health Care Quality Improvement Projects.

    PubMed

    Balbale, Salva N; Locatelli, Sara M; LaVela, Sherri L

    2016-08-01

    In this methodological article, we examine participatory methods in depth to demonstrate how these methods can be adopted for quality improvement (QI) projects in health care. We draw on existing literature and our QI initiatives in the Department of Veterans Affairs to discuss the application of photovoice and guided tours in QI efforts. We highlight lessons learned and several benefits of using participatory methods in this area. Using participatory methods, evaluators can engage patients, providers, and other stakeholders as partners to enhance care. Participant involvement helps yield actionable data that can be translated into improved care practices. Use of these methods also helps generate key insights to inform improvements that truly resonate with stakeholders. Using participatory methods is a valuable strategy to harness participant engagement and drive improvements that address individual needs. In applying these innovative methodologies, evaluators can transcend traditional approaches to uniquely support evaluations and improvements in health care. © The Author(s) 2015.

  14. How the baby learns to see: Donald O. Hebb Award Lecture, Canadian Society for Brain, Behaviour, and Cognitive Science, Ottawa, June 2015.

    PubMed

    Maurer, Daphne

    2016-09-01

    Hebb's (1949) book The Organisation of Behaviour presented a novel hypothesis about how the baby learns to see. This article summarizes the results of my research program that evaluated Hebb's hypothesis: first, by studying infants' eye movements and initial perceptual abilities and second, by studying the effect of visual deprivation (e.g., congenital cataracts) on later perceptual development. Collectively, the results support Hebb's hypothesis that the baby does indeed learn to see. Early visual experience not only drives the baby's initial scanning of objects, but also sets up the neural architecture that will come to underlie adults' perception. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Brinzolamide Ophthalmic

    MedlinePlus

    ... see if you should still use the same eye drop bottle.tell your doctor if you wear soft contact lenses. Wait at least 15 minutes after using the medicine to put in soft contact lenses.use caution when driving or operating machinery because vision may be blurred after inserting the drops.

  16. Spirit's View Beside 'Home Plate' on Sol 1823 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11971 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11971

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,823rd Martian day, or sol, of Spirit's surface mission (Feb. 17, 2009).

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The center of the view is toward the south-southwest.

    The rover had driven 7 meters (23 feet) eastward earlier on Sol 1823, part of maneuvering to get Spirit into a favorable position for climbing onto the low plateau called 'Home Plate.' However, after two driving attempts with negligible progress during the following three sols, the rover team changed its strategy for getting to destinations south of Home Plate. The team decided to drive Spirit at least partway around Home Plate, instead of ascending the northern edge and taking a shorter route across the top of the plateau.

    Layered rocks forming part of the northern edge of Home Plate can be seen near the center of the image. Rover wheel tracks are visible at the lower edge.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  17. Selectively driving cholinergic fibers optically in the thalamic reticular nucleus promotes sleep

    PubMed Central

    Ni, Kun-Ming; Hou, Xiao-Jun; Yang, Ci-Hang; Dong, Ping; Li, Yue; Zhang, Ying; Jiang, Ping; Berg, Darwin K; Duan, Shumin; Li, Xiao-Ming

    2016-01-01

    Cholinergic projections from the basal forebrain and brainstem are thought to play important roles in rapid eye movement (REM) sleep and arousal. Using transgenic mice in which channelrhdopsin-2 is selectively expressed in cholinergic neurons, we show that optical stimulation of cholinergic inputs to the thalamic reticular nucleus (TRN) activates local GABAergic neurons to promote sleep and protect non-rapid eye movement (NREM) sleep. It does not affect REM sleep. Instead, direct activation of cholinergic input to the TRN shortens the time to sleep onset and generates spindle oscillations that correlate with NREM sleep. It does so by evoking excitatory postsynaptic currents via α7-containing nicotinic acetylcholine receptors and inducing bursts of action potentials in local GABAergic neurons. These findings stand in sharp contrast to previous reports of cholinergic activity driving arousal. Our results provide new insight into the mechanisms controlling sleep. DOI: http://dx.doi.org/10.7554/eLife.10382.001 PMID:26880556

  18. 38 CFR 4.75 - General considerations for evaluating visual impairment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-connected visual impairment of only one eye. Subject to the provisions of 38 CFR 3.383(a), if visual impairment of only one eye is service-connected, the visual acuity of the other eye will be considered to be... visual impairment of one eye. The evaluation for visual impairment of one eye must not exceed 30 percent...

  19. 38 CFR 4.75 - General considerations for evaluating visual impairment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-connected visual impairment of only one eye. Subject to the provisions of 38 CFR 3.383(a), if visual impairment of only one eye is service-connected, the visual acuity of the other eye will be considered to be... visual impairment of one eye. The evaluation for visual impairment of one eye must not exceed 30 percent...

  20. Using Eye Trackers for Usability Evaluation of Health Information Technology: A Systematic Literature Review

    PubMed Central

    Yang, Yushi

    2015-01-01

    Background Eye-tracking technology has been used to measure human cognitive processes and has the potential to improve the usability of health information technology (HIT). However, it is still unclear how the eye-tracking method can be integrated with other traditional usability methodologies to achieve its full potential. Objective The objective of this study was to report on HIT evaluation studies that have used eye-tracker technology, and to envision the potential use of eye-tracking technology in future research. Methods We used four reference databases to initially identify 5248 related papers, which resulted in only 9 articles that met our inclusion criteria. Results Eye-tracking technology was useful in finding usability problems in many ways, but is still in its infancy for HIT usability evaluation. Limited types of HITs have been evaluated by eye trackers, and there has been a lack of evaluation research in natural settings. Conclusions More research should be done in natural settings to discover the real contextual-based usability problems of clinical and mobile HITs using eye-tracking technology with more standardized methodologies and guidance. PMID:27026079

  1. An assessment of driving fitness in patients with visual impairment to understand the elevated risk of motor vehicle accidents

    PubMed Central

    Kunimatsu-Sanuki, Shiho; Iwase, Aiko; Araie, Makoto; Aoki, Yuki; Hara, Takeshi; Nakazawa, Toru; Yamaguchi, Takuhiro; Ono, Hiroshi; Sanuki, Tomoyuki; Itoh, Makoto

    2015-01-01

    Objective To assess the driving fitness of patients with glaucoma by identifying specific areas and degrees of visual field impairment that threaten safe driving. Design Case–control study. Setting, and participants This prospective study included 36 patients with advanced glaucoma, defined as Humphrey field analyzer (HFA; 24-2 SITA standard program) measurements of mean deviation in both eyes of worse than −12 dB, and 36 age-matched and driving exposure time-matched normal subjects. All participants underwent testing in a novel driving simulator (DS) system. Participants were recruited between September 2010 and January 2012. Main outcome measures The number of collisions with simulated hazards and braking response time in 14 DS scenarios was recorded. Monocular HFA 24-2 test results from both eyes were merged to calculate the binocular integrated visual field (IVF). The position of the IVF subfields in which the collision-involved patients had lower sensitivity than the collision-uninvolved patients was compared with the track of the hazard. The cut-off value to predict an elevated risk of collisions was determined, as were its sensitivity and specificity, with the area under the receiver operating characteristic (AUROC) curve. Results Patients with advanced glaucoma were involved in a significantly higher number of collisions in the DS than the age-matched and driving exposure time-matched normal subjects (119 vs 40, respectively, p<0.0001), especially in four specific DS scenarios. In these four scenarios, IVF sensitivity was significantly lower in the collision-involved patients than in the collision-uninvolved patients in subfields on or near the track of the simulated hazard (p<0.05). The subfields with the largest AUROC curve had values ranging from 0.72 to 0.91 and were located in the paracentral visual field just below the horizontal. Conclusions Our novel DS system effectively assessed visual impairment, showing that simulators may have future potential in educating patients. PMID:25724982

  2. Evaluation of a community-based participatory farmworker eye health intervention in the "black dirt" region of New York state.

    PubMed

    Earle-Richardson, Giulia; Wyckoff, Lynae; Carrasquillo, Marilyn; Scribani, Melissa; Jenkins, Paul; May, John

    2014-09-01

    Eye irritation is a constant hazard for migrant and seasonal farmworkers, but there are few studies of the problem or how to address it. Researchers evaluated the effect of a community-based participatory eye health intervention on farmworker eye symptoms in the Hudson Valley, NY. A randomized pre-post intervention with 2, 4-week follow-up periods was implemented with a sample of 97 farmworkers. Five eye symptoms were measured, along with utilization of protective eyewear and eye drops. Leading baseline eye symptoms were redness (49%), blurred vision (43%), itching (43%), and eye pain (29%). Significant reductions in eye pain (P = 0.009), and non-significant reductions in redness were observed for the intervention group while controls experienced increases in both. The intervention was effective in significantly reducing eye pain, and to a lesser extent, redness. Future eyewear promotion programs should offer a range of eye wear, tailor offerings to local climate and tasks, evaluate eyewear durability, and include eye drops. © 2014 Wiley Periodicals, Inc.

  3. Measuring vigilance decrement using computer vision assisted eye tracking in dynamic naturalistic environments.

    PubMed

    Bodala, Indu P; Abbasi, Nida I; Yu Sun; Bezerianos, Anastasios; Al-Nashash, Hasan; Thakor, Nitish V

    2017-07-01

    Eye tracking offers a practical solution for monitoring cognitive performance in real world tasks. However, eye tracking in dynamic environments is difficult due to high spatial and temporal variation of stimuli, needing further and thorough investigation. In this paper, we study the possibility of developing a novel computer vision assisted eye tracking analysis by using fixations. Eye movement data is obtained from a long duration naturalistic driving experiment. Source invariant feature transform (SIFT) algorithm was implemented using VLFeat toolbox to identify multiple areas of interest (AOIs). A new measure called `fixation score' was defined to understand the dynamics of fixation position between the target AOI and the non target AOIs. Fixation score is maximum when the subjects focus on the target AOI and diminishes when they gaze at the non-target AOIs. Statistically significant negative correlation was found between fixation score and reaction time data (r =-0.2253 and p<;0.05). This implies that with vigilance decrement, the fixation score decreases due to visual attention shifting away from the target objects resulting in an increase in the reaction time.

  4. Methodical aspects of text testing in a driving simulator.

    PubMed

    Sundin, A; Patten, C J D; Bergmark, M; Hedberg, A; Iraeus, I-M; Pettersson, I

    2012-01-01

    A test with 30 test persons was conducted in a driving simulator. The test was a concept exploration and comparison of existing user interaction technologies for text message handling with focus on traffic safety and experience (technology familiarity and learning effects). Focus was put on methodical aspects how to measure and how to analyze the data. Results show difficulties with the eye tracking system (calibration etc.) per se, and also include the subsequent raw data preparation. The physical setup in the car where found important for the test completion.

  5. Evaluation of Different Power of Near Addition in Two Different Multifocal Intraocular Lenses

    PubMed Central

    Unsal, Ugur; Baser, Gonen

    2016-01-01

    Purpose. To compare near, intermediate, and distance vision and quality of vision, when refractive rotational multifocal intraocular lenses with 3.0 diopters or diffractive multifocal intraocular lenses with 2.5 diopters near addition are implanted. Methods. 41 eyes of 41 patients in whom rotational +3.0 diopters near addition IOLs were implanted and 30 eyes of 30 patients in whom diffractive +2.5 diopters near addition IOLs were implanted after cataract surgery were reviewed. Uncorrected and corrected distance visual acuity, intermediate visual acuity, near visual acuity, and patient satisfaction were evaluated 6 months later. Results. The corrected and uncorrected distance visual acuity were the same between both groups (p = 0.50 and p = 0.509, resp.). The uncorrected intermediate and corrected intermediate and near vision acuities were better in the +2.5 near vision added intraocular lens implanted group (p = 0.049, p = 0.005, and p = 0.001, resp.) and the uncorrected near vision acuity was better in the +3.0 near vision added intraocular lens implanted group (p = 0.001). The patient satisfactions of both groups were similar. Conclusion. The +2.5 diopters near addition could be a better choice in younger patients with more distance and intermediate visual requirements (driving, outdoor activities), whereas the + 3.0 diopters should be considered for patients with more near vision correction (reading). PMID:27340560

  6. Implicit prosody mining based on the human eye image capture technology

    NASA Astrophysics Data System (ADS)

    Gao, Pei-pei; Liu, Feng

    2013-08-01

    The technology of eye tracker has become the main methods of analyzing the recognition issues in human-computer interaction. Human eye image capture is the key problem of the eye tracking. Based on further research, a new human-computer interaction method introduced to enrich the form of speech synthetic. We propose a method of Implicit Prosody mining based on the human eye image capture technology to extract the parameters from the image of human eyes when reading, control and drive prosody generation in speech synthesis, and establish prosodic model with high simulation accuracy. Duration model is key issues for prosody generation. For the duration model, this paper put forward a new idea for obtaining gaze duration of eyes when reading based on the eye image capture technology, and synchronous controlling this duration and pronunciation duration in speech synthesis. The movement of human eyes during reading is a comprehensive multi-factor interactive process, such as gaze, twitching and backsight. Therefore, how to extract the appropriate information from the image of human eyes need to be considered and the gaze regularity of eyes need to be obtained as references of modeling. Based on the analysis of current three kinds of eye movement control model and the characteristics of the Implicit Prosody reading, relative independence between speech processing system of text and eye movement control system was discussed. It was proved that under the same text familiarity condition, gaze duration of eyes when reading and internal voice pronunciation duration are synchronous. The eye gaze duration model based on the Chinese language level prosodic structure was presented to change previous methods of machine learning and probability forecasting, obtain readers' real internal reading rhythm and to synthesize voice with personalized rhythm. This research will enrich human-computer interactive form, and will be practical significance and application prospect in terms of disabled assisted speech interaction. Experiments show that Implicit Prosody mining based on the human eye image capture technology makes the synthesized speech has more flexible expressions.

  7. Lifestyle Determinants on Prevention and Improvement of Dry Eye Disease from the Perspective of Iranian Traditional Medicine.

    PubMed

    Haji-Ali-Nili, Neda; Khoshzaban, Fariba; Karimi, Mehrdad

    2016-05-01

    Dry eye disease is one of the most common public health problems in the field of ophthalmology that causes decreased physical, psychological, social and occupational functioning, and interferes with daily activities like reading, driving, computer work and watching TV. The effect of this disease on quality of life is similar to severe migraine and angina. In addition, the severity of the disease is closely related to depression. Outbreaks are increasing with the use of contact lenses and refractive surgery such as LASIK. The purpose of this paper is to assess the causes of dry eye and its prevention by the principles of hygiene. In this review study, traditional medicine resources like Al canon fil tibb, Sharh-al-Al Asbab and Exir-e-azam have been studied with engine motors such as Google Scholar and PubMed. From the perspective of Iranian traditional medicine, the principles of maintaining health include air, food and drink, exercise and rest, sleep and wakefulness, mental state, retention of essential materials and depletion of wastes from the body. Proper performance of each principle is useful for the prevention of disease in different organs, including the eyes. Recommendations for the prevention or treatment of dry eye disease include the prevention of dryness in the eye or the entire body. In addition, the stomach and brain are important to eye health. Accordingly, one of the most effective managements of dry eye disease is avoiding foods that affect the eye in this way; for example garlic and onion. Maintaining eye health is related to aspects of physical and mental health of the whole body. Therefore, codification of an integrated plan that contains eating and sleeping patterns, exercise, general clearing, eye clearing, and mental health is essential for treating dry eye disease.

  8. Eye-Pursuit and Reafferent Head Movement Signals Carried by Pursuit Neurons in the Caudal Part of the Frontal Eye Fields during Head-Free Pursuit

    PubMed Central

    Kasahara, Satoshi; Akao, Teppei; Kurkin, Sergei; Peterson, Barry W.

    2009-01-01

    Eye and head movements are coordinated during head-free pursuit. To examine whether pursuit neurons in frontal eye fields (FEF) carry gaze-pursuit commands that drive both eye-pursuit and head-pursuit, monkeys whose heads were free to rotate about a vertical axis were trained to pursue a juice feeder with their head and a target with their eyes. Initially the feeder and target moved synchronously with the same visual angle. FEF neurons responding to this gaze-pursuit were tested for eye-pursuit of target motion while the feeder was stationary and for head-pursuit while the target was stationary. The majority of pursuit neurons exhibited modulation during head-pursuit, but their preferred directions during eye-pursuit and head-pursuit were different. Although peak modulation occurred during head movements, the onset of discharge usually was not aligned with the head movement onset. The minority of neurons whose discharge onset was so aligned discharged after the head movement onset. These results do not support the idea that the head-pursuit–related modulation reflects head-pursuit commands. Furthermore, modulation similar to that during head-pursuit was obtained by passive head rotation on stationary trunk. Our results suggest that FEF pursuit neurons issue gaze or eye movement commands during gaze-pursuit and that the head-pursuit–related modulation primarily reflects reafferent signals resulting from head movements. PMID:18483002

  9. Preparation of Nonhuman Primate Eyes for Histological Evaluation After Retinal Gene Transfer.

    PubMed

    Bell, Peter; Yu, Hongwei; Kuntz, Leah; Ahonkhai, Omua; Tretiakova, Anna; Limberis, Maria P; Wilson, James M

    2018-06-01

    To evaluate gene therapy for retinal disorders, appropriate models of the human eye are needed. Nonhuman primate eyes offer significant advantages over rodent eyes. However, current preparation methods have limitations. Here, a protocol is described for histological processing of nonhuman primate eyes after gene transfer. The user dissects unfixed eyes, flattens the globe parts within filter paper, and performs formalin fixation and paraffin embedding. This method obviates the need for harsh fixatives, allowing subsequent immunostaining or in situ hybridization while preserving tissue integrity for histopathological evaluation. Moreover, the straight orientation of the retinal cell layers is ideal for image analysis.

  10. Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators

    DTIC Science & Technology

    2017-07-07

    AFRL-RH-FS-TR-2017-0026 Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators Thomas K. Kuyk Peter A. Smith Solangia...34Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators" (AFRL-RH-FS-TR- 2017 - 0026 SHORTER.PATRI CK.D.1023156390 Digitally...SUBTITLE Flight Tasks and Metrics to Evaluate Laser Eye Protection in Flight Simulators 5a. CONTRACT NUMBER FA8650-14-D-6519 5b. GRANT NUMBER 5c

  11. Callous-unemotional traits in children and mechanisms of impaired eye contact during expressions of love: a treatment target?

    PubMed

    Dadds, Mark R; Allen, Jennifer L; McGregor, Kimberley; Woolgar, Matthew; Viding, Essi; Scott, Stephen

    2014-07-01

    We previously hypothesised that the early development of psychopathy is associated with a failure to attend to the eyes of attachment figures, and we have presented preliminary data from a parent-child 'love' scenario in support of this. Here, we confirm the association in a larger sample and test mechanisms of impaired eye contact during expressions of love in control and behaviourally disturbed children. Oppositional defiant disorder children, assessed for callous-unemotional (CU) traits, and controls, were observed in a brief interaction task where the mother was asked to show love to her child. Eye contact and affection were measured for each dyad. As predicted, there were no group differences in affection and eye contact expressed by mothers; levels of CU traits predicted low levels of eye contact towards their mothers across all groups of children. As expected, low eye contact was correlated with psychopathic fearlessness in their fathers, and maternal reports of negative feelings towards the child. Independent observations showed that child's behaviour largely drives the low eye contact associated with CU traits, and low eye contact was not associated with independent observations of the quality of attachment-related behaviours in mothers. Impaired eye contact is a unique characteristic of children with CU traits; these impairments are largely independent of maternal behaviour, but associated with psychopathic traits in the fathers. These impairments should be tested for functional significance and amenability to change in longitudinal and treatment studies. © 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.

  12. Four-year follow-up of corneal aberrations and visual functions of myopic patients after laser in situ keratomileusis

    PubMed Central

    Liu, Tai-Xiang; Chen, Yong-Tao; Dan, Ting-Ting; Shi, Rong; Linghu, Shao-Rong; Li, Hai-Xiang

    2015-01-01

    Objective: To report on 4-year follow-up of corneal higher-order aberrations and daily visual functions of myopic patients after laser in situ keratomileusis (LASIK). Methods: One hundred thirty four eyes of 67 patients who underwent LASIK guided by aspherical ablation were included in this study. The vision, corneal spherical aberration (SphA) and Coma were recorded before LASIK and at 6 month and 4 year after LASIK. The evaluation of the questionnaire about daily visual functions was performed by the same physician after LASIK. Results: No eye decreased the BCVA during 4 year follow-up. The effect index and safety index were 1.08±0.16, 1.11±0.17 and 1.12±0.16, 1.13±0.14 respectively at 6 month and 4 year post-LASIK. After LASIK the corneal SphA and Coma were significantly increased, however the difference between 6 month and 4 year post-LASIK was no statistical significance. Most patients (94.3%-92.4%) felt satisfaction or high satisfaction about the ability to perform each daily visual function after LASIK. Meanwhile there was still about 7.4%-9.2% patients who complained that they could not drive at night. Further analysis showed that the score of driving at night was negative correlation with corneal SphA (r=-0.645, p=0.040; r=-0.688, p=0.040 at 6 month and 4 year post-LASIK respectively). Conclusions: Our four-year follow-up outcomes indicated that the myopic patients after LASIK had the long-term stable corneal aberration and satisfaction of daily visual functions. PMID:26870114

  13. Standard eye exam

    MedlinePlus

    Standard ophthalmic exam; Routine eye examination; Eye exam - standard; Annual eye exam ... Comprehensive adult medical eye evaluation preferred practice pattern guidelines. Ophthalmology . 2016;123(1):209-236. PMID: 26581558 ...

  14. Why do drivers become safer over the first three months of driving? A longitudinal qualitative study.

    PubMed

    Day, Marianne R; Thompson, Andrew R; Poulter, Damian R; Stride, Christopher B; Rowe, Richard

    2018-08-01

    Drivers are at high crash risk when they begin independent driving, with liability decreasing steeply over the first three months. Their behavioural development, and other changes underlying improved safety are not well understood. We adopted an innovative longitudinal qualitative design, with thirteen newly qualified drivers completing a total of 36 semi-structured interviews, one, two and three months after acquiring a full UK driving license. The interviews probed high-risk factors for new drivers, as well as allowing space for generating novel road safety issues. Analysis adopted a dual deductive and inductive interpretative thematic approach, identifying three super-ordinate themes: (1) Improvements in car control skills and situation awareness; (2) A reduction in the thrill of taking risks when driving against a background of generally increasing driving speed; (3) Early concerns about their social status in the eyes of other road users during the early stages of driving, which may put pressure on them to drive faster than they felt comfortable with. The study provides important new leads towards understanding how novice driving becomes safer over the first few months of driving, including how well-studied concepts of driving skill and style may change during development of independent driving, and bringing the less rigorously studied concept of social status into focus. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Driving characteristics of teens with attention deficit hyperactivity and autism spectrum disorder.

    PubMed

    Classen, Sherrilene; Monahan, Miriam; Wang, Yanning

    2013-01-01

    Vehicle crashes are a leading cause of death among teens. Teens with attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), or both (ADHD-ASD) may have a greater crash risk. We examined the between-groups demographic, clinical, and predriving performance differences of 22 teens with ADHD-ASD (mean age = 15.05, standard deviation [SD] = 0.95) and 22 healthy control (HC) teens (mean age = 14.32, SD = 0.72). Compared with HC teens, the teens with ADHD-ASD performed more poorly on right-eye visual acuity, selective attention, visual-motor integration, cognition, and motor performance and made more errors on the driving simulator pertaining to visual scanning, speed regulation, lane maintenance, adjustment to stimuli, and total number of driving errors. Teens with ADHD-ASD, compared with HC teens, may have more predriving deficits and as such require the skills of a certified driving rehabilitation specialist to assess readiness to drive. Copyright © 2013 by the American Occupational Therapy Association, Inc.

  16. A multimodal dataset for various forms of distracted driving

    PubMed Central

    Taamneh, Salah; Tsiamyrtzis, Panagiotis; Dcosta, Malcolm; Buddharaju, Pradeep; Khatri, Ashik; Manser, Michael; Ferris, Thomas; Wunderlich, Robert; Pavlidis, Ioannis

    2017-01-01

    We describe a multimodal dataset acquired in a controlled experiment on a driving simulator. The set includes data for n=68 volunteers that drove the same highway under four different conditions: No distraction, cognitive distraction, emotional distraction, and sensorimotor distraction. The experiment closed with a special driving session, where all subjects experienced a startle stimulus in the form of unintended acceleration—half of them under a mixed distraction, and the other half in the absence of a distraction. During the experimental drives key response variables and several explanatory variables were continuously recorded. The response variables included speed, acceleration, brake force, steering, and lane position signals, while the explanatory variables included perinasal electrodermal activity (EDA), palm EDA, heart rate, breathing rate, and facial expression signals; biographical and psychometric covariates as well as eye tracking data were also obtained. This dataset enables research into driving behaviors under neatly abstracted distracting stressors, which account for many car crashes. The set can also be used in physiological channel benchmarking and multispectral face recognition. PMID:28809848

  17. The Cost-Effectiveness of Three Screening Alternatives for People with Diabetes with No or Early Diabetic Retinopathy

    PubMed Central

    Rein, David B; Wittenborn, John S; Zhang, Xinzhi; Allaire, Benjamin A; Song, Michael S; Klein, Ronald; Saaddine, Jinan B

    2011-01-01

    Objective To determine whether biennial eye evaluation or telemedicine screening are cost-effective alternatives to current recommendations for the estimated 10 million people aged 30–84 with diabetes but no or minimal diabetic retinopathy. Data Sources United Kingdom Prospective Diabetes Study, National Health and Nutrition Examination Survey, American Academy of Ophthalmology Preferred Practice Patterns, Medicare Payment Schedule. Study Design Cost-effectiveness Monte Carlo simulation. Data Collection/Extraction Methods Literature review, analysis of existing surveys. Principal Findings Biennial eye evaluation was the most cost-effective treatment option when the ability to detect other eye conditions was included in the model. Telemedicine was most cost-effective when other eye conditions were not considered or when telemedicine was assumed to detect refractive error. The current annual eye evaluation recommendation was costly compared with either treatment alternative. Self-referral was most cost-effective up to a willingness to pay (WTP) of U.S.$37,600, with either biennial or annual evaluation most cost-effective at higher WTP levels. Conclusions Annual eye evaluations are costly and add little benefit compared with either plausible alternative. More research on the ability of telemedicine to detect other eye conditions is needed to determine whether it is more cost-effective than biennial eye evaluation. PMID:21492158

  18. The effect of image sharpness on quantitative eye movement data and on image quality evaluation while viewing natural images

    NASA Astrophysics Data System (ADS)

    Vuori, Tero; Olkkonen, Maria

    2006-01-01

    The aim of the study is to test both customer image quality rating (subjective image quality) and physical measurement of user behavior (eye movements tracking) to find customer satisfaction differences in imaging technologies. Methodological aim is to find out whether eye movements could be quantitatively used in image quality preference studies. In general, we want to map objective or physically measurable image quality to subjective evaluations and eye movement data. We conducted a series of image quality tests, in which the test subjects evaluated image quality while we recorded their eye movements. Results show that eye movement parameters consistently change according to the instructions given to the user, and according to physical image quality, e.g. saccade duration increased with increasing blur. Results indicate that eye movement tracking could be used to differentiate image quality evaluation strategies that the users have. Results also show that eye movements would help mapping between technological and subjective image quality. Furthermore, these results give some empirical emphasis to top-down perception processes in image quality perception and evaluation by showing differences between perceptual processes in situations when cognitive task varies.

  19. Frequency, Contingency and Online Processing of Multiword Sequences: An Eye-Tracking Study

    ERIC Educational Resources Information Center

    Yi, Wei; Lu, Shiyi; Ma, Guojie

    2017-01-01

    Frequency and contingency are two primary statistical factors that drive the acquisition and processing of language. This study explores the role of phrasal frequency and contingency (the co-occurrence probability/statistical association of the constituent words in multiword sequences) during online processing of multiword sequences. Meanwhile, it…

  20. Haldane’s Rule Is Linked to Extraordinary Sex Ratios and Sperm Length in Stalk-Eyed Flies

    PubMed Central

    Wilkinson, Gerald S.; Christianson, Sarah J.; Brand, Cara L.; Ru, George; Shell, Wyatt

    2014-01-01

    We use three allopatric populations of the stalk-eyed fly Teleopsis dalmanni from Southeast Asia to test two predictions made by the sex chromosome drive hypothesis for Haldane’s rule. The first is that modifiers that suppress or enhance drive should evolve rapidly and independently in isolated populations. The second is that drive loci or modifiers should also cause sterility in hybrid males. We tested these predictions by assaying the fertility of 2066 males derived from backcross experiments involving two pairs of populations and found that the proportion of mated males that fail to produce any offspring ranged from 38 to 60% among crosses with some males producing strongly female-biased or male-biased sex ratios. After genotyping each male at 25–28 genetic markers we found quantitative trait loci (QTL) that jointly influence male sterility, sperm length, and biased progeny sex ratios in each pair of populations, but almost no shared QTL between population crosses. We also discovered that the extant XSR chromosome has no effect on sex ratio or sterility in these backcross males. Whether shared QTL are caused by linkage or pleiotropy requires additional study. Nevertheless, these results indicate the presence of a “cryptic” drive system that is currently masked by suppressing elements that are associated with sterility and sperm length within but not between populations and, therefore, must have evolved since the populations became isolated, i.e., in <100,000 years. We discuss how genes that influence sperm length may contribute to hybrid sterility. PMID:25164880

  1. Increasing Spontaneous Retinal Activity before Eye Opening Accelerates the Development of Geniculate Receptive Fields

    PubMed Central

    Davis, Zachary W.; Chapman, Barbara

    2015-01-01

    Visually evoked activity is necessary for the normal development of the visual system. However, little is known about the capacity for patterned spontaneous activity to drive the maturation of receptive fields before visual experience. Retinal waves provide instructive retinotopic information for the anatomical organization of the visual thalamus. To determine whether retinal waves also drive the maturation of functional responses, we increased the frequency of retinal waves pharmacologically in the ferret (Mustela putorius furo) during a period of retinogeniculate development before eye opening. The development of geniculate receptive fields after receiving these increased neural activities was measured using single-unit electrophysiology. We found that increased retinal waves accelerate the developmental reduction of geniculate receptive field sizes. This reduction is due to a decrease in receptive field center size rather than an increase in inhibitory surround strength. This work reveals an instructive role for patterned spontaneous activity in guiding the functional development of neural circuits. SIGNIFICANCE STATEMENT Patterned spontaneous neural activity that occurs during development is known to be necessary for the proper formation of neural circuits. However, it is unknown whether the spontaneous activity alone is sufficient to drive the maturation of the functional properties of neurons. Our work demonstrates for the first time an acceleration in the maturation of neural function as a consequence of driving patterned spontaneous activity during development. This work has implications for our understanding of how neural circuits can be modified actively to improve function prematurely or to recover from injury with guided interventions of patterned neural activity. PMID:26511250

  2. GPS Usage in a Population of Low-Vision Drivers.

    PubMed

    Cucuras, Maria; Chun, Robert; Lee, Patrick; Jay, Walter M; Pusateri, Gregg

    2017-01-01

    We surveyed bioptic and non-bioptic low-vision drivers in Illinois, USA, to determine their usage of global positioning system (GPS) devices. Low-vision patients completed an IRB-approved phone survey regarding driving demographics and usage of GPS while driving. Participants were required to be active drivers with an Illinois driver's license, and met one of the following criteria: best-corrected visual acuity (BCVA) less than or equal to 20/40, central or significant peripheral visual field defects, or a combination of both. Of 27 low-vision drivers, 10 (37%) used GPS while driving. The average age for GPS users was 54.3 and for non-users was 77.6. All 10 drivers who used GPS while driving reported increased comfort or safety level. Since non-GPS users were significantly older than GPS users, it is likely that older participants would benefit from GPS technology training from their low-vision eye care professionals.

  3. Ultrawide-field Fluorescein Angiography for Evaluation of Diabetic Retinopathy

    PubMed Central

    Kong, Mingui; Lee, Mee Yon

    2012-01-01

    Purpose To investigate the advantages of ultrawide-field fluorescein angiography (FA) over the standard fundus examination in the evaluation of diabetic retinopathy (DR). Methods Ultrawide-field FAs were obtained in 118 eyes of 59 diabetic patients; 11 eyes with no DR, 71 eyes with nonproliferative diabetic retinopathy (NPDR), and 36 eyes with proliferative diabetic retinopathy (PDR), diagnosed by the standard method. The presence of peripheral abnormal lesions beyond the standard seven fields was examined. Results Ultrawide-field FA images demonstrated peripheral microaneurysms in six (54.5%) of 11 eyes with no DR and all eyes with moderate to severe NPDR and PDR. Peripheral retinal neovascularizations were detected in three (4.2%) of 71 eyes with NPDR and in 13 (36.1%) of 36 eyes with PDR. Peripheral vascular nonperfusion and vascular leakage were found in two-thirds of eyes with severe NPDR and PDR. Conclusions Ultrawide-field FA demonstrates peripheral lesions beyond standard fields, which can allow early detection and a close evaluation of DR. PMID:23204797

  4. 77 FR 41406 - Evaluation of In Vitro Tests for Identifying Eye Injury Hazard Potential of Chemicals and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Evaluation of In Vitro Tests for Identifying Eye Injury...-animal testing strategies proposed for identifying eye injury hazard potential of chemicals and products... Panel and submission of data from substances tested in in vitro tests for identifying eye injury hazard...

  5. Sensorimotor and postural control factors associated with driving safety in a community-dwelling older driver population.

    PubMed

    Lacherez, Philippe; Wood, Joanne M; Anstey, Kaarin J; Lord, Stephen R

    2014-02-01

    To establish whether sensorimotor function and balance are associated with on-road driving performance in older adults. The performance of 270 community-living adults aged 70-88 years recruited via the electoral roll was measured on a battery of peripheral sensation, strength, flexibility, reaction time, and balance tests and on a standardized measure of on-road driving performance. Forty-seven participants (17.4%) were classified as unsafe based on their driving assessment. Unsafe driving was associated with reduced peripheral sensation, lower limb weakness, reduced neck range of motion, slow reaction time, and poor balance in univariate analyses. Multivariate logistic regression analysis identified poor vibration sensitivity, reduced quadriceps strength, and increased sway on a foam surface with eyes closed as significant and independent risk factors for unsafe driving. These variables classified participants into safe and unsafe drivers with a sensitivity of 74% and specificity of 70%. A number of sensorimotor and balance measures were associated with driver safety and the multivariate model comprising measures of sensation, strength, and balance was highly predictive of unsafe driving in this sample. These findings highlight important determinants of driver safety and may assist in developing efficacious driver safety strategies for older drivers.

  6. Illusory motion reveals velocity matching, not foveation, drives smooth pursuit of large objects

    PubMed Central

    Ma, Zheng; Watamaniuk, Scott N. J.; Heinen, Stephen J.

    2017-01-01

    When small objects move in a scene, we keep them foveated with smooth pursuit eye movements. Although large objects such as people and animals are common, it is nonetheless unknown how we pursue them since they cannot be foveated. It might be that the brain calculates an object's centroid, and then centers the eyes on it during pursuit as a foveation mechanism might. Alternatively, the brain merely matches the velocity by motion integration. We test these alternatives with an illusory motion stimulus that translates at a speed different from its retinal motion. The stimulus was a Gabor array that translated at a fixed velocity, with component Gabors that drifted with motion consistent or inconsistent with the translation. Velocity matching predicts different pursuit behaviors across drift conditions, while centroid matching predicts no difference. We also tested whether pursuit can segregate and ignore irrelevant local drifts when motion and centroid information are consistent by surrounding the Gabors with solid frames. Finally, observers judged the global translational speed of the Gabors to determine whether smooth pursuit and motion perception share mechanisms. We found that consistent Gabor motion enhanced pursuit gain while inconsistent, opposite motion diminished it, drawing the eyes away from the center of the stimulus and supporting a motion-based pursuit drive. Catch-up saccades tended to counter the position offset, directing the eyes opposite to the deviation caused by the pursuit gain change. Surrounding the Gabors with visible frames canceled both the gain increase and the compensatory saccades. Perceived speed was modulated analogous to pursuit gain. The results suggest that smooth pursuit of large stimuli depends on the magnitude of integrated retinal motion information, not its retinal location, and that the position system might be unnecessary for generating smooth velocity to large pursuit targets. PMID:29090315

  7. Regressive Evolution in the Mexican Cave Tetra, Astyanax mexicanus

    PubMed Central

    Protas, Meredith; Conrad, Melissa; Gross, Joshua B.; Tabin, Clifford; Borowsky, Richard

    2007-01-01

    Summary Cave adapted animals generally have reduced pigmentation and eyes, but the evolutionary forces driving the reductions are unknown; Darwin famously questioned the role of natural selection in eye loss in cave fishes; “As it is difficult to imagine that eyes, although useless, could be in any way injurious to animals living in darkness, I attribute their loss wholly to disuse” [1]. We studied the genetic basis of this phenomenon in the Mexican cave tetra, Astyanax mexicanus, by mapping the quantitative trait loci (QTL) determining differences in eye/lens sizes and melanophore number between cave and surface fish. In addition, we mapped QTL for the putatively constructive traits of jaw size, tooth number, and numbers of taste buds. The data suggest that eyes and pigmentation regressed through different mechanisms. Cave alleles at each eye/lens QTL we detected caused size reductions. This uniform negative polarity is consistent with evolution by natural selection and inconsistent with evolution by drift. In contrast, QTL polarities for melanophore number were mixed, consistent with evolution by genetic drift or indirect selection through pleiotropy. Past arguments against a role for selection in regression of cave fish eyes cited the insignificant cost of their development [2, 3], but we argue that the energetic cost of their maintenance is sufficiently high for eyes to be detrimental in the cave environment. Regression, a ubiquitous aspect of all evolutionary change, can be caused either by selection or genetic drift/pleiotropy. PMID:17306543

  8. Design of DroDeASys (Drowsy Detection and Alarming System)

    NASA Astrophysics Data System (ADS)

    Juvale, Hrishikesh B.; Mahajan, Anant S.; Bhagwat, Ashwin A.; Badiger, Vishal T.; Bhutkar, Ganesh D.; Dhabe, Priyadarshan S.; Dhore, Manikrao L.

    The paper discusses the Drowsy Detection & Alarming System that has been developed, using a non-intrusive approach. The system is basically developed to detect drivers dozing at the wheel at night time driving. The system uses a small infra-red night vision camera that points directly towards the driver`s face and monitors the driver`s eyes in order to detect fatigue. In such a case when fatigue is detected, a warning signal is issued to alert the driver. This paper discusses the algorithms that have been used to detect drowsiness. The decision whether the driver is dozing or not is taken depending on whether the eyes are open for a specific number of frames. If the eyes are found to be closed for a certain number of consecutive frames then the driver is alerted with an alarm.

  9. Research on driver fatigue detection

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Chen, Zhong; Ouyang, Chao

    2018-03-01

    Driver fatigue is one of the main causes of frequent traffic accidents. In this case, driver fatigue detection system has very important significance in avoiding traffic accidents. This paper presents a real-time method based on fusion of multiple facial features, including eye closure, yawn and head movement. The eye state is classified as being open or closed by a linear SVM classifier trained using HOG features of the detected eye. The mouth state is determined according to the width-height ratio of the mouth. The head movement is detected by head pitch angle calculated by facial landmark. The driver's fatigue state can be reasoned by the model trained by above features. According to experimental results, drive fatigue detection obtains an excellent performance. It indicates that the developed method is valuable for the application of avoiding traffic accidents caused by driver's fatigue.

  10. Contextual effects on smooth-pursuit eye movements.

    PubMed

    Spering, Miriam; Gegenfurtner, Karl R

    2007-02-01

    Segregating a moving object from its visual context is particularly relevant for the control of smooth-pursuit eye movements. We examined the interaction between a moving object and a stationary or moving visual context to determine the role of the context motion signal in driving pursuit. Eye movements were recorded from human observers to a medium-contrast Gaussian dot that moved horizontally at constant velocity. A peripheral context consisted of two vertically oriented sinusoidal gratings, one above and one below the stimulus trajectory, that were either stationary or drifted into the same or opposite direction as that of the target at different velocities. We found that a stationary context impaired pursuit acceleration and velocity and prolonged pursuit latency. A drifting context enhanced pursuit performance, irrespective of its motion direction. This effect was modulated by context contrast and orientation. When a context was briefly perturbed to move faster or slower eye velocity changed accordingly, but only when the context was drifting along with the target. Perturbing a context into the direction orthogonal to target motion evoked a deviation of the eye opposite to the perturbation direction. We therefore provide evidence for the use of absolute and relative motion cues, or motion assimilation and motion contrast, for the control of smooth-pursuit eye movements.

  11. ENLARGEMENT OF FOVEAL AVASCULAR ZONE IN DIABETIC EYES EVALUATED BY EN FACE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

    PubMed

    Takase, Noriaki; Nozaki, Miho; Kato, Aki; Ozeki, Hironori; Yoshida, Munenori; Ogura, Yuichiro

    2015-11-01

    To evaluate the area of the foveal avascular zone (FAZ) detected by en face OCTA (AngioVue, Avanti OCT; Optovue) in healthy and diabetic eyes. Retrospective chart review of patients who underwent fundus examination including en face OCTA. Eyes with proliferative diabetic retinopathy and history of laser photocoagulation were excluded. The FAZ area in the superficial and deep plexus layers were measured and evaluated using ImageJ software. The FAZ area in the superficial layer was 0.25 ± 0.06 mm² in healthy eyes (n = 19), whereas it was 0.37 ± 0.07 mm² in diabetic eyes without retinopathy (n = 24) and 0.38 ± 0.11 mm² in eyes with diabetic retinopathy (n = 20). Diabetic eyes showed statistically significant FAZ enlargement compared with healthy eyes, regardless of the presence of retinopathy (P < 0.01). The FAZ area in the deep plexus layer was also significantly larger in diabetic eyes than in healthy eyes (P < 0.01). Our data suggest that diabetic eyes show retinal microcirculation impairment in the macula even before retinopathy develops. En face OCTA is a useful noninvasive screening tool for detecting early microcirculatory disturbance in patients with diabetes.

  12. Optimization and validation of an existing, surgical and robust dry eye rat model for the evaluation of therapeutic compounds.

    PubMed

    Joossen, Cedric; Lanckacker, Ellen; Zakaria, Nadia; Koppen, Carina; Joossens, Jurgen; Cools, Nathalie; De Meester, Ingrid; Lambeir, Anne-Marie; Delputte, Peter; Maes, Louis; Cos, Paul

    2016-05-01

    The aim of this research was to optimize and validate an animal model for dry eye, adopting clinically relevant evaluation parameters. Dry eye was induced in female Wistar rats by surgical removal of the exorbital lacrimal gland. The clinical manifestations of dry eye were evaluated by tear volume measurements, corneal fluorescein staining, cytokine measurements in tear fluid, MMP-9 mRNA expression and CD3(+) cell infiltration in the conjunctiva. The animal model was validated by treatment with Restasis(®) (4 weeks) and commercial dexamethasone eye drops (2 weeks). Removal of the exorbital lacrimal gland resulted in 50% decrease in tear volume and a gradual increase in corneal fluorescein staining. Elevated levels of TNF-α and IL-1α have been registered in tear fluid together with an increase in CD3(+) cells in the palpebral conjunctiva when compared to control animals. Additionally, an increase in MMP-9 mRNA expression was recorded in conjunctival tissue. Reference treatment with Restasis(®) and dexamethasone eye drops had a positive effect on all evaluation parameters, except on tear volume. This rat dry eye model was validated extensively and judged appropriate for the evaluation of novel compounds and therapeutic preparations for dry eye disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Multi-modal demands of a smartphone used to place calls and enter addresses during highway driving relative to two embedded systems

    PubMed Central

    Reimer, Bryan; Mehler, Bruce; Reagan, Ian; Kidd, David; Dobres, Jonathan

    2016-01-01

    Abstract There is limited research on trade-offs in demand between manual and voice interfaces of embedded and portable technologies. Mehler et al. identified differences in driving performance, visual engagement and workload between two contrasting embedded vehicle system designs (Chevrolet MyLink and Volvo Sensus). The current study extends this work by comparing these embedded systems with a smartphone (Samsung Galaxy S4). None of the voice interfaces eliminated visual demand. Relative to placing calls manually, both embedded voice interfaces resulted in less eyes-off-road time than the smartphone. Errors were most frequent when calling contacts using the smartphone. The smartphone and MyLink allowed addresses to be entered using compound voice commands resulting in shorter eyes-off-road time compared with the menu-based Sensus but with many more errors. Driving performance and physiological measures indicated increased demand when performing secondary tasks relative to ‘just driving’, but were not significantly different between the smartphone and embedded systems. Practitioner Summary: The findings show that embedded system and portable device voice interfaces place fewer visual demands on the driver than manual interfaces, but they also underscore how differences in system designs can significantly affect not only the demands placed on drivers, but also the successful completion of tasks. PMID:27110964

  14. Velocity servo for continuous scan Fourier interference spectrometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A. (Inventor)

    1980-01-01

    A velocity servo for continuous scan Fourier interference spectrometer of the double pass retroreflector type having two cat's eye retroreflectors is described. The servo uses an open loop, lead screw drive system for one retroreflector with compensation for any variations in speed of drive of the lead screw provided by sensing any variation in the rate of reference laser fringes, and producing an error signal from such variation used to compensate by energizing a moving coil actuator for the other retroreflector optical path, and energizing (through a highpass filter) piezoelectric actuators for the secondary mirrors of the retroreflectors.

  15. Ultra-widefield fluorescein angiography of white without pressure

    PubMed Central

    Orlin, Anton; Fatoo, Aalya; Ehrlich, Joshua; D’Amico, Donald J; Chan, RV Paul; Kiss, Szilárd

    2013-01-01

    Purpose To describe ultra-widefield fluorescein angiography (UWFA) findings in eyes with white without pressure (WWOP) and in eyes without any obvious peripheral chorioretinal disease, and to determine if a difference exists between these two groups. Methods A retrospective review of 379 eyes undergoing diagnostic UWFA using the Optos 200Tx imaging system. Eyes were excluded if the quality of the color photograph or UWFA prevented reliable evaluation. Eyes were also excluded if there was any evidence of peripheral retinal or choroidal disease, which was thought to have an effect on UWFA (eg, peripheral background diabetic or hypertensive retinopathy, vein occlusion, or any other peripheral vascular disorder). Eyes were determined to have WWOP, based on a dilated fundus examination and color fundus photography that contained areas of peripheral retinal whitening consistent with the diagnosis. UWFA was evaluated by trained masked graders, and determined to have or not have peripheral vascular leakage and/or staining. Results Of the 379 eyes evaluated, 45 eyes were included in the study. Twelve eyes were determined to have peripheral WWOP; 33 eyes did not have WWOP on examination or color fundus photography. Three common UWFA peripheral patterns were visualized. Eyes with and without WWOP were grouped into one of three patterns. The majority of eyes without WWOP demonstrated UWFA pattern one (69.7%), while those in the WWOP group demonstrated pattern three (50%). The distribution of UWFA patterns is statistically different between those with and without WWOP (P = 0.002). In eyes without WWOP, in patients with no documented systemic microvascular disease (diabetes, hypertension), 71.4% of eyes had UWFA pattern one while 14.3% had both patterns two and three. Conclusion This study is one of the first to specifically evaluate peripheral vascular leakage/staining in eyes with WWOP as well as in eyes without any obvious peripheral chorioretinal disease. We demonstrate that a significant portion of WWOP eyes exhibit peripheral findings on UWFA (pattern one) compared to eyes without WWOP. Importantly, even in eyes that are apparently unremarkable in the periphery on exam and color photography, UWFA can still show peripheral vascular abnormalities. These results warrant further investigation. PMID:23737658

  16. Pathological evaluation of postmortem human eyes implanted with a new single-piece hydrophobic acrylic lens.

    PubMed

    Izak, Andrea M; Werner, Liliana; Pandey, Suresh K; Apple, David J

    2004-07-01

    To report the pathological findings in 14 human cadaver eyes implanted with a single-piece AcrySof(Alcon Laboratories) posterior chamber intraocular lens (IOL). David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Fourteen human autopsy eyes implanted with a single-piece AcrySof (SA30AL) IOL were evaluated. The eyes were sectioned at the equatorial plane, and the anterior segment containing the IOL in the capsular bag was evaluated from a posterior perspective (Miyake-Apple view) and from an anterior perspective (surgeon's view) after removal of cornea and iris. They were then processed through paraffin, sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome and examined under light microscopy. All IOLs had symmetric in-the-bag fixation. Slight decentration was measured in 1 eye, which also had an anterior capsule tear. Grade 1 anterior capsule opacification was present in 9 eyes. No central posterior capsule opacification or posterior capsule folds were observed in any eye. Soemmering's ring formation was observed in 5 eyes. Zonular stretch caused by different degrees of capsular bag contraction was present in 4 eyes without decentration of the IOL. Analyses of pseudophakic cadaver eyes from the posterior (Miyake-Apple) view, complemented by microscopic analyses, proved useful in the evaluation of IOL-capsular bag interaction. These studies are more important in cases of newly introduced lens designs.

  17. Clinical guidelines for management of dry eye associated with Sjögren disease.

    PubMed

    Foulks, Gary N; Forstot, S Lance; Donshik, Peter C; Forstot, Joseph Z; Goldstein, Michael H; Lemp, Michael A; Nelson, J Daniel; Nichols, Kelly K; Pflugfelder, Stephen C; Tanzer, Jason M; Asbell, Penny; Hammitt, Katherine; Jacobs, Deborah S

    2015-04-01

    To provide a consensus clinical guideline for management of dry eye disease associated with Sjögren disease by evaluating published treatments and recommending management options. Consensus panel evaluation of reported treatments for dry eye disease. Using the 2007 Report of the International Workshop on Dry Eye (DEWS) as a starting point, a panel of eye care providers and consultants evaluated peer-reviewed publications and developed recommendations for evaluation and management of dry eye disease associated with Sjögren disease. Publications were graded according to the American Academy of Ophthalmology Preferred Practice Pattern guidelines for level of evidence. Strength of recommendation was according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines. The recommendations of the panel are briefly summarized herein. Evaluation should include symptoms of both discomfort and visual disturbance as well as determination of the relative contribution of aqueous production deficiency and evaporative loss of tear volume. Objective parameters of tear film stability, tear osmolarity, degree of lid margin disease, and ocular surface damage should be used to stage severity of dry eye disease to assist in selecting appropriate treatment options. Patient education with regard to the nature of the problem, aggravating factors, and goals of treatment is critical to successful management. Tear supplementation and stabilization, control of inflammation of the lacrimal glands and ocular surface, and possible stimulation of tear production are treatment options that are used according to the character and severity of dry eye disease. Management guidelines for dry eye associated with Sjögren's disease are presented. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. The Hydrogen Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2012-01-01

    Handling dangerous substances has come to define a society. People drive around with the explosive equivalent of twenty sticks of dynamite in their gasoline tanks without batting an eye. They use open flames to cook their food and heat their homes. Propane barbecue tanks are sold everywhere in the country, and left outside their homes for several…

  19. 76 FR 73769 - Qualification of Drivers; Exemption Applications; Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ... moving violations in a CMV. Mark A. Ferris Mr. Ferris, 55, has had amblyopia in his left eye since... an examination in 2011, his optometrist noted, ``In my professional opinion, Mr. Ferris has more than sufficient vision to perform the driving tasks required to operate any commercial motor vehicle.'' Mr. Ferris...

  20. High risk of near-crash driving events following night-shift work

    PubMed Central

    Lee, Michael L.; Howard, Mark E.; Horrey, William J.; Liang, Yulan; Anderson, Clare; Shreeve, Michael S.; O’Brien, Conor S.; Czeisler, Charles A.

    2016-01-01

    Night-shift workers are at high risk of drowsiness-related motor vehicle crashes as a result of circadian disruption and sleep restriction. However, the impact of actual night-shift work on measures of drowsiness and driving performance while operating a real motor vehicle remains unknown. Sixteen night-shift workers completed two 2-h daytime driving sessions on a closed driving track at the Liberty Mutual Research Institute for Safety: (i) a postsleep baseline driving session after an average of 7.6 ± 2.4 h sleep the previous night with no night-shift work, and (ii) a postnight-shift driving session following night-shift work. Physiological measures of drowsiness were collected, including infrared reflectance oculography, electroencephalography, and electrooculography. Driving performance measures included lane excursions, near-crash events, and drives terminated because of failure to maintain control of the vehicle. Eleven near-crashes occurred in 6 of 16 postnight-shift drives (37.5%), and 7 of 16 postnight-shift drives (43.8%) were terminated early for safety reasons, compared with zero near-crashes or early drive terminations during 16 postsleep drives (Fishers exact: P = 0.0088 and P = 0.0034, respectively). Participants had a significantly higher rate of lane excursions, average Johns Drowsiness Scale, blink duration, and number of slow eye movements during postnight-shift drives compared with postsleep drives (3.09/min vs. 1.49/min; 1.71 vs. 0.97; 125 ms vs. 100 ms; 35.8 vs. 19.1; respectively, P < 0.05 for all). Night-shift work increases driver drowsiness, degrading driving performance and increasing the risk of near-crash drive events. With more than 9.5 million Americans working overnight or rotating shifts and one-third of United States commutes exceeding 30 min, these results have implications for traffic and occupational safety. PMID:26699470

  1. High risk of near-crash driving events following night-shift work.

    PubMed

    Lee, Michael L; Howard, Mark E; Horrey, William J; Liang, Yulan; Anderson, Clare; Shreeve, Michael S; O'Brien, Conor S; Czeisler, Charles A

    2016-01-05

    Night-shift workers are at high risk of drowsiness-related motor vehicle crashes as a result of circadian disruption and sleep restriction. However, the impact of actual night-shift work on measures of drowsiness and driving performance while operating a real motor vehicle remains unknown. Sixteen night-shift workers completed two 2-h daytime driving sessions on a closed driving track at the Liberty Mutual Research Institute for Safety: (i) a postsleep baseline driving session after an average of 7.6 ± 2.4 h sleep the previous night with no night-shift work, and (ii) a postnight-shift driving session following night-shift work. Physiological measures of drowsiness were collected, including infrared reflectance oculography, electroencephalography, and electrooculography. Driving performance measures included lane excursions, near-crash events, and drives terminated because of failure to maintain control of the vehicle. Eleven near-crashes occurred in 6 of 16 postnight-shift drives (37.5%), and 7 of 16 postnight-shift drives (43.8%) were terminated early for safety reasons, compared with zero near-crashes or early drive terminations during 16 postsleep drives (Fishers exact: P = 0.0088 and P = 0.0034, respectively). Participants had a significantly higher rate of lane excursions, average Johns Drowsiness Scale, blink duration, and number of slow eye movements during postnight-shift drives compared with postsleep drives (3.09/min vs. 1.49/min; 1.71 vs. 0.97; 125 ms vs. 100 ms; 35.8 vs. 19.1; respectively, P < 0.05 for all). Night-shift work increases driver drowsiness, degrading driving performance and increasing the risk of near-crash drive events. With more than 9.5 million Americans working overnight or rotating shifts and one-third of United States commutes exceeding 30 min, these results have implications for traffic and occupational safety.

  2. Functional brain mapping of actual car-driving using [18F]FDG-PET.

    PubMed

    Jeong, Myeonggi; Tashiro, Manabu; Singh, Laxsmi N; Yamaguchi, Keiichiro; Horikawa, Etsuo; Miyake, Masayasu; Watanuki, Shouichi; Iwata, Ren; Fukuda, Hiroshi; Takahashi, Yasuo; Itoh, Masatoshi

    2006-11-01

    This study aims at identifying the brain activation during actual car-driving on the road, and at comparing the results to those of previous studies on simulated car-driving. Thirty normal volunteers, aged 20 to 56 years, were divided into three subgroups, active driving, passive driving and control groups, for examination by positron emission tomography (PET) and [18F]2-deoxy-2-fluoro-D-glucose (FDG). The active driving subjects (n = 10) drove for 30 minutes on quiet normal roads with a few traffic signals. The passive driving subjects (n = 10) participated as passengers on the front seat. The control subjects (n = 10) remained seated in a lit room with their eyes open. Voxel-based t-statistics were applied using SPM2 to search brain activation among the subgroups mentioned above. Significant brain activation was detected during active driving in the primary and secondary visual cortices, primary sensorimotor areas, premotor area, parietal association area, cingulate gyrus, the parahippocampal gyrus as well as in thalamus and cerebellum. The passive driving manifested a similar-looking activation pattern, lacking activations in the premotor area, cingulate and parahippocampal gyri and thalamus. Direct comparison of the active and passive driving conditions revealed activation in the cerebellum. The result of actual driving looked similar to that of simulated driving, suggesting that visual perception and visuomotor coordination were the main brain functions while driving. In terms of attention and autonomic arousal, however, it seems there was a significant difference between simulated and actual driving possibly due to risk of accidents. Autonomic and emotional aspects of driving should be studied using an actual driving study-design.

  3. Driving time modulates accommodative response and intraocular pressure.

    PubMed

    Vera, Jesús; Diaz-Piedra, Carolina; Jiménez, Raimundo; Morales, José M; Catena, Andrés; Cardenas, David; Di Stasi, Leandro L

    2016-10-01

    Driving is a task mainly reliant on the visual system. Most of the time, while driving, our eyes are constantly focusing and refocusing between the road and the dashboard or near and far traffic. Thus, prolonged driving time should produce visual fatigue. Here, for the first time, we investigated the effects of driving time, a common inducer of driver fatigue, on two ocular parameters: the accommodative response (AR) and the intraocular pressure (IOP). A pre/post-test design has been used to assess the impact of driving time on both indices. Twelve participants (out of 17 recruited) completed the study (5 women, 24.42±2.84years old). The participants were healthy and active drivers with no visual impairment or pathology. They drove for 2h in a virtual driving environment. We assessed AR and IOP before and after the driving session, and also collected subjective measures of arousal and fatigue. We found that IOP and AR decreased (i.e., the accommodative lag increased) after the driving session (p=0.03 and p<0.001, respectively). Moreover, the nearest distances tested (20cm, 25cm, and 33cm) induced the highest decreases in AR (corrected p-values<0.05). Consistent with these findings, the subjective levels of arousal decreased and levels of fatigue increased after the driving session (all p-values<0.001). These results represent an innovative step towards an objective, valid, and reliable assessment of fatigue-impaired driving based on visual fatigue signs. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Meal assistance robot with ultrasonic motor

    NASA Astrophysics Data System (ADS)

    Kodani, Yasuhiro; Tanaka, Kanya; Wakasa, Yuji; Akashi, Takuya; Oka, Masato

    2007-12-01

    In this paper, we have constructed a robot that help people with disabilities of upper extremities and advanced stage amyotrophic lateral sclerosis (ALS) patients to eat with their residual abilities. Especially, many of people suffering from advanced stage ALS of the use a pacemaker. And they need to avoid electromagnetic waves. Therefore we adopt ultra sonic motor that does not generate electromagnetic waves as driving sources. Additionally we approach the problem of the conventional meal assistance robot. Moreover, we introduce the interface with eye movement so that extremities can also use our system. User operates our robot not with hands or foot but with eye movement.

  5. Identifying and assessing strategies for evaluating the impact of mobile eye health units on health outcomes.

    PubMed

    Fu, Shiwan; Turner, Angus; Tan, Irene; Muir, Josephine

    2017-12-01

    To identify and assess strategies for evaluating the impact of mobile eye health units on health outcomes. Systematic literature review. Worldwide. Peer-reviewed journal articles that included the use of a mobile eye health unit. Journal articles were included if outcome measures reflected an assessment of the impact of a mobile eye health unit on health outcomes. Six studies were identified with mobile services offering diabetic retinopathy screening (three studies), optometric services (two studies) and orthoptic services (one study). This review identified and assessed strategies in existing literature used to evaluate the impact of mobile eye health units on health outcomes. Studies included in this review used patient outcomes (i.e. disease detection, vision impairment, treatment compliance) and/or service delivery outcomes (i.e. cost per attendance, hospital transport use, inappropriate referrals, time from diabetic retinopathy photography to treatment) to evaluate the impact of mobile eye health units. Limitations include difficulty proving causation of specific outcome measures and the overall shortage of impact evaluation studies. Variation in geographical location, service population and nature of eye care providers limits broad application. © 2017 National Rural Health Alliance Inc.

  6. Harvesting experiential expertise to support safe driving for people with diabetes mellitus: a qualitative study evaluated by peers in a survey.

    PubMed

    Burda, Marika H F; van der Horst, Frans; van den Akker, Marjan; Stork, Alexander D M; Mesters, Ilse; Bours, Silvia; Ploeg, Maarten; Winkens, Bjorn; Knottnerus, Johannes A

    2012-01-01

    Hypoglycemia is a frequent phenomenon in people being treated for diabetes mellitus, which can acutely disrupt driving performance. For the benefit of personal and public traffic safety, we decided to identify successful diabetes-related (SDR) behaviors to support safe driving for people with diabetes, from the perspective of experiential experts with diabetes mellitus. Experiential experts are people who can manage their own illness and conditions by developing expertise relevant to maintaining health and countering illness, and who are able to use this expertise to the benefit of peers. The aim of our study was to objectify and systematize experiential expertise in terms of SDR behaviors, based on reports by experiential experts, to support safe driving for people with type 1 and type 2 diabetes mellitus. The emphasis was on preventing hypoglycemia as a short-term complication during driving. We performed a mixed-methods study involving (i) semi-structured in-depth interviews with 33 experiential experts with diabetes mellitus from the Dutch Diabetes Association (DVN; Diabetesvereniging Nederland), in order to identify SDR behaviors regarding safe driving, and (ii) a validation study by means of a survey among a panel of 98 experiential experts (peers) from the DVN, to determine the extent to which they agreed with the communicability, importance, and feasibility of these behaviors for drivers with diabetes mellitus. We identified a comprehensive set of 11 SDR behaviors, differentiated into seven general and four specific behaviors, to support safe driving. The general behaviors concern the following topics: (i) acquiring knowledge and information; (ii) acquiring and using self-measuring of blood glucose (SMBG) equipment; (iii) knowing one's physical response pattern; (iv) obtaining knowledge about the medication used; (v) preventing long-term eye complications; (vi) influencing factors that can affect blood glucose; and (vii) renewal procedure for driving license. The four specific behaviors refer to the following topics: (i) measures to be taken before driving; (ii) responding effectively to hypoglycemia while driving; (iii) informing and instructing passengers; and (iv) preventing hypoglycemia in drivers with type 2 diabetes mellitus not using SMBG equipment. Key factors for safe driving proved to be the ability of drivers to anticipate and respond effectively to hypoglycemia while driving and to inform and instruct fellow passengers. Participants of the validation survey agreed to a considerable degree with the communicability, importance, and feasibility of these behaviors to support safe driving for people with diabetes mellitus. This study resulted in the identification and description of SDR behaviors to support safe driving. It proved possible to operationalize experiential expertise in terms of such behaviors. The next step is to have these behaviors validated by professional care providers in the field of diabetes, followed by translation into recommendations in self-management programs.

  7. Recent advances in laser in situ keratomileusis-associated dry eye.

    PubMed

    Xie, Wenjia

    2016-03-01

    Dry eye is the most common complication after laser in situ keratomileusis (LASIK). The major cause of LASIK-associated dry eye is corneal nerve damage. Early identification and treatment of post-operative dry eye are essential to prevent further ocular surface damage. This article reviews the recent studies of LASIK-associated dry eye, including clinical features, aetiology, risk factors, evaluations and treatment. The applications of novel technologies in LASIK-associated dry eye evaluation like anterior segment spectral-domain optical coherence tomography (SD-OCT) and corneal confocal microscopy are also introduced in this review. © 2016 Optometry Australia.

  8. Evaluation and comparison of indentation ultrasound biomicroscopy gonioscopy in relative pupillary block, peripheral anterior synechia, and plateau iris configuration.

    PubMed

    Matsunaga, Koichi; Ito, Kunio; Esaki, Koji; Sugimoto, Kota; Sano, Toru; Miura, Katsuya; Sasoh, Mikio; Uji, Yukitaka

    2004-12-01

    To evaluate and compare the findings and changes of the anterior chamber angle configuration with indentation ultrasound biomicroscopy (UBM) gonioscopy in relative pupillary block (RPB), peripheral anterior synechia (PAS), and plateau iris configuration (PIC). This study included 73 eyes of 52 patients with RPB (n = 26), PAS (n = 21), or PIC (n = 26). First, a conventional UBM scan was performed using a normal size standard eye cup before indentation. Then, for indentation UBM gonioscopy, scans were performed using a new eye cup that we designed. For evaluation of the angle, angle opening distance 500 and angle recess area were recorded and evaluated with regard to the effect of expansion on the anterior chamber angle. Indentation UBM gonioscopy showed the characteristic images in each of the eyes. The angle of all examined eyes was significantly widened with indentation (P < 0.01). The angle changes in eyes with RPB were significantly greater than in eyes with PAS or PIC (P < 0.01). Indentation UBM gonioscopy is a very useful method for observing the angle and diagnosis of RPB, PAS, and PIC.

  9. Relationships Between Meibomian Gland Loss and Age, Sex, and Dry Eye.

    PubMed

    Pult, Heiko

    2018-02-12

    This study evaluated relationships between meibomian gland loss (MGL) and age, sex, and dry eye. Dry eye and MGL of the lower eyelid was evaluated from 112 randomly selected subjects (66 women; mean age 62.8; SD ±15.7; and age range: 19-89 years) from Horst Riede GmbH, Weinheim, Germany. In addition, subjects were grouped into dry eye and non-dry eye by the Ocular Surface Disease Index (OSDI) score, lid-parallel conjunctival folds and non-invasive break-up time. Symptoms were evaluated by the OSDI. Meibography of the lower eyelid was performed using a Cobra camera (bon Optic, Lübeck, Germany), and images were analyzed by its digital grading tool. Data were analyzed by backward, multiple regression analyses and Pearson correlation. Analyzing all subjects, multiple regression analyses detected that age and dry eye status (dry eye diagnosis or OSDI) but not sex were significantly related to MGL. In both, non-dry eye (n=66) and dry eye subjects (n=46), dry eye status (OSDI) but not age or sex was significantly related to MGL. Ocular Surface Disease Index scores were significantly correlated with MGL, but this correlation was stronger among all subjects (Pearson correlation; r=0.536, P<0.001) and dry eye group subjects (r=0.520, P<0.001) than in non-dry eye group subjects (r=0.275, P=0.014). Dry eye group subjects showed significantly increased MGL of the lower eyelid. Age and dry eye status were related to MGL of the lower eyelid, but sex was not; dry eye status was the dominant factor.

  10. Consistency between subjectively and objectively measured hazard perception skills among young male drivers.

    PubMed

    Ābele, Līva; Haustein, Sonja; Møller, Mette; Martinussen, Laila M

    2018-03-01

    Young male drivers have lower hazard perception skills (HPS) than older and more experienced drivers and a tendency to overestimate their skills in hazardous situations. Both factors contribute to an over-representation in traffic accidents. Based on a sample of 63 drivers aged 18-24, this study compares the consistency of HPS measured by objective and subjective measures and the link between these measures is the key contribution of the study. Both visible and hidden hazards are included. Objective measures of HPS include responsiveness and eye movements while driving in a driving simulator. Subjective measures of HPS include self-reports derived based on the Hazard Perception Questionnaire (HPQ), Driving Skill Questionnaire (DSQ), and Brief Sensation Seeking Scale (BSSS). Results show that drivers who respond to the hazards on time, as compared to drivers who do not respond, have higher scores on subjective measures of HPS and higher driving skills in the visible but not in the hidden condition. Eye movement analysis confirms the difference and shows that response in time to hazards indicate higher HPS and young drivers are poor at detecting hidden hazards. Drivers with a response in time locate the hazard faster, have more fixations, but dwell less on the hazard. At the same time, those who do not respond have a later first fixation and fewer but longer fixations on the hazard. High sensation seeking drivers respond to visible hazards on time, suggesting that sensation seeking does not affect HPS negatively when the hazard is visible. To enhance the HPS among young drivers, the results of this study suggest that specific hazard perception training is relevant, especially for hazards that require more advanced HPS. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Analysis of naturalistic driving videos of fleet services drivers to estimate driver error and potentially distracting behaviors as risk factors for rear-end versus angle crashes.

    PubMed

    Harland, Karisa K; Carney, Cher; McGehee, Daniel

    2016-07-03

    The objective of this study was to estimate the prevalence and odds of fleet driver errors and potentially distracting behaviors just prior to rear-end versus angle crashes. Analysis of naturalistic driving videos among fleet services drivers for errors and potentially distracting behaviors occurring in the 6 s before crash impact. Categorical variables were examined using the Pearson's chi-square test, and continuous variables, such as eyes-off-road time, were compared using the Student's t-test. Multivariable logistic regression was used to estimate the odds of a driver error or potentially distracting behavior being present in the seconds before rear-end versus angle crashes. Of the 229 crashes analyzed, 101 (44%) were rear-end and 128 (56%) were angle crashes. Driver age, gender, and presence of passengers did not differ significantly by crash type. Over 95% of rear-end crashes involved inadequate surveillance compared to only 52% of angle crashes (P < .0001). Almost 65% of rear-end crashes involved a potentially distracting driver behavior, whereas less than 40% of angle crashes involved these behaviors (P < .01). On average, drivers spent 4.4 s with their eyes off the road while operating or manipulating their cell phone. Drivers in rear-end crashes were at 3.06 (95% confidence interval [CI], 1.73-5.44) times adjusted higher odds of being potentially distracted than those in angle crashes. Fleet driver driving errors and potentially distracting behaviors are frequent. This analysis provides data to inform safe driving interventions for fleet services drivers. Further research is needed in effective interventions to reduce the likelihood of drivers' distracting behaviors and errors that may potentially reducing crashes.

  12. Driver self-regulation and depressive symptoms in cataract patients awaiting surgery: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Cataract is an extremely common visual condition of ageing. Evidence suggests that visual impairment influences driving patterns and self-regulatory behavior among older drivers. However, little is known about the psychological effects of driver self-regulation among older drivers. Therefore, this study aimed to describe driver self-regulation practices among older bilateral cataract patients and to determine the association between self-regulation and depressive symptoms. Methods Ninety-nine older drivers with bilateral cataract were assessed the week before first eye cataract surgery. Driver self-regulation was measured via the Driving Habits Questionnaire. Depressive symptoms were assessed using the 20-item Center for Epidemiological Studies Depression Scale. Visual, demographic and cognitive data were also collected. Differences between self-regulators and non self-regulators were described and linear regression modeling used to determine the association between driver self-regulation and depressive symptoms score. Results Among cataract patients, 48% reported self-regulating their driving to avoid at least one challenging situation. The situations most commonly avoided were driving at night (40%), on the freeway (12%), in the rain (9%) and parallel parking (8%). Self-regulators had significantly poorer contrast sensitivity in their worse eye than non self-regulators (p = 0.027). Driver self-regulation was significantly associated with increased depressive symptoms after controlling for potential confounding factors (p = 0.002). Conclusions Driver self-regulation was associated with increased depressive symptoms among cataract patients. Further research should investigate this association among the general older population. Self-regulation programs aimed at older drivers may need to incorporate mental health elements to counteract unintended psychological effects. PMID:24016307

  13. Ocular Coherence Tomography in the Evaluation of Anterior Eye Injuries in Space Flight

    NASA Technical Reports Server (NTRS)

    Fer, Dan M.; Law, Jennifer; Wells, Julia

    2017-01-01

    While Ocular Coherence Tomography (OCT) is not a first-line modality to evaluate anterior eye structures terrestrially, it is a resource already available on the International Space Station (ISS) that can be used in medical contingencies that involve the anterior eye. With remote guidance and subject matter expert (SME) support from the ground, a minimally trained crewmember can now use OCT to evaluate anterior eye pathologies on orbit. OCT utilizes low-coherence interferometry to produce detailed cross-sectional and 3D images of the eye in real time. Terrestrially, it has been used to evaluate macular pathologies and glaucoma. Since 2013, OCT has been used onboard the ISS as one part of a suite of hardware to evaluate the Visual Impairment/Intracranial Pressure risk faced by astronauts, specifically assessing changes in the retina and choroid during space flight. The Anterior Segment Module (ASM), an add-on lens, was also flown for research studies, providing an opportunity to evaluate the anterior eye in real time if clinically indicated. Anterior eye pathologies that could be evaluated using OCT were identified. These included corneal abrasions and ulcers, scleritis, and acute angle closure glaucoma. A remote guider script was written to provide ground specialists with step-by-step instructions to guide ISS crewmembers, who do not get trained on the ASM, to evaluate the anterior eye. The instructions were tested on novice subjects and/or operators, whose feedback was incorporated iteratively. The final remote guider script was reviewed by SME optometrists and NASA flight surgeons. The novel application of OCT technology to space flight allows for the acquisition of objective data to diagnose anterior eye pathologies when other modalities are not available. This demonstrates the versatility of OCT and highlights the advantages of using existing hardware and remote guidance skills to expand clinical capabilities in space flight.

  14. Sensory impairment and driving: the Blue Mountains Eye Study.

    PubMed Central

    Ivers, R Q; Mitchell, P; Cumming, R G

    1999-01-01

    OBJECTIVES: This study examined the associations between vision, hearing, loss, and car accidents. METHODS: A cross-sectional survey of 3654 people aged 49 years and older in the Blue Mountains, Australia, was used. Each subject had a detailed eye examination and interview. RESULTS: Self-reported car accident rates in the past year among 2379 current drivers were 5.6% for those aged 49 to 79 years and 9.1% for those 80 years and older. A 2-line difference in visual acuity was associated with increased risk of accidents (adjusted prevalence ratio [PR] = 1.6), as was visual acuity worse than 6/18 in the right eye (PR = 2.0), overall moderate hearing loss (PR = 1.9), and hearing loss in the right ear (PR = 1.8). CONCLUSIONS: Sensory loss in drivers may be an important risk factor for car accidents. PMID:9987472

  15. Automatic Calibration Method for Driver’s Head Orientation in Natural Driving Environment

    PubMed Central

    Fu, Xianping; Guan, Xiao; Peli, Eli; Liu, Hongbo; Luo, Gang

    2013-01-01

    Gaze tracking is crucial for studying driver’s attention, detecting fatigue, and improving driver assistance systems, but it is difficult in natural driving environments due to nonuniform and highly variable illumination and large head movements. Traditional calibrations that require subjects to follow calibrators are very cumbersome to be implemented in daily driving situations. A new automatic calibration method, based on a single camera for determining the head orientation and which utilizes the side mirrors, the rear-view mirror, the instrument board, and different zones in the windshield as calibration points, is presented in this paper. Supported by a self-learning algorithm, the system tracks the head and categorizes the head pose in 12 gaze zones based on facial features. The particle filter is used to estimate the head pose to obtain an accurate gaze zone by updating the calibration parameters. Experimental results show that, after several hours of driving, the automatic calibration method without driver’s corporation can achieve the same accuracy as a manual calibration method. The mean error of estimated eye gazes was less than 5°in day and night driving. PMID:24639620

  16. The cost-effectiveness of Welcome to Medicare visual acuity screening and a possible alternative welcome to medicare eye evaluation among persons without diagnosed diabetes mellitus.

    PubMed

    Rein, David B; Wittenborn, John S; Zhang, Xinzhi; Hoerger, Thomas J; Zhang, Ping; Klein, Barbara Eden Kobrin; Lee, Kris E; Klein, Ronald; Saaddine, Jinan B

    2012-05-01

    To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy. Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population. Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years(QALYs) by 0.008 (95% credible interval [CrI], 0.005-0.011) and increased costs by $94 (95% CrI, −$35 to$222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and$12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective. The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, anew policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective.

  17. The Cost-effectiveness of Welcome to Medicare Visual Acuity Screening and a Possible Alternative Welcome to Medicare Eye Evaluation Among Persons Without Diagnosed Diabetes Mellitus

    PubMed Central

    Rein, David B.; Wittenborn, John S.; Zhang, Xinzhi; Hoerger, Thomas J.; Zhang, Ping; Klein, Barbara Eden Kobrin; Lee, Kris E.; Klein, Ronald; Saaddine, Jinan B.

    2013-01-01

    Objective To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy. Design Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population. Results Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years (QALYs) by 0.008 (95% credible interval [CrI], 0.005–0.011) and increased costs by $94 (95% CrI, −$35 to $222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and $12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective. Conclusions The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, a new policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective. PMID:22232367

  18. Assessing the Potential Use of Eye-Tracking Triangulation for Evaluating the Usability of an Online Diabetes Exercise System.

    PubMed

    Schaarup, Clara; Hartvigsen, Gunnar; Larsen, Lars Bo; Tan, Zheng-Hua; Årsand, Eirik; Hejlesen, Ole Kristian

    2015-01-01

    The Online Diabetes Exercise System was developed to motivate people with Type 2 diabetes to do a 25 minutes low-volume high-intensity interval training program. In a previous multi-method evaluation of the system, several usability issues were identified and corrected. Despite the thorough testing, it was unclear whether all usability problems had been identified using the multi-method evaluation. Our hypothesis was that adding the eye-tracking triangulation to the multi-method evaluation would increase the accuracy and completeness when testing the usability of the system. The study design was an Eye-tracking Triangulation; conventional eye-tracking with predefined tasks followed by The Post-Experience Eye-Tracked Protocol (PEEP). Six Areas of Interests were the basis for the PEEP-session. The eye-tracking triangulation gave objective and subjective results, which are believed to be highly relevant for designing, implementing, evaluating and optimizing systems in the field of health informatics. Future work should include testing the method on a larger and more representative group of users and apply the method on different system types.

  19. Survey of Ophthalmologists Regarding Practice Patterns for Dry Eye and Sjogren Syndrome.

    PubMed

    Bunya, Vatinee Y; Fernandez, Karen B; Ying, Gui-Shuang; Massaro-Giordano, Mina; Macchi, Ilaria; Sulewski, Michael E; Hammersmith, Kristin M; Nagra, Parveen K; Rapuano, Christopher J; Orlin, Stephen E

    2018-01-15

    To survey ophthalmologists about current practice patterns regarding the evaluation of dry eye patients and referrals for a Sjogren syndrome (SS) workup. An online survey was sent to ophthalmologists affiliated with the Scheie Eye Institute or Wills Eye Hospital using REDCap in August 2015. Descriptive statistics were used to summarize the data. Four hundred seventy-four survey invitations were sent out and 101 (21%) ophthalmologists completed the survey. The common traditional dry eye test performed was corneal fluorescein staining (62%) and the most common newer dry eye test performed was tear osmolarity (18%). Half of respondents (51%) refer fewer than 5% of their dry eye patients for SS workups, with 18% reporting that they never refer any patients. The most common reasons for referrals included positive review of systems (60%), severe dry eye symptoms (51%) or ocular signs (47%), or dry eye that is refractory to treatment (42%). The majority (83%) felt that there is a need for an evidence-based standardized screening tool for dry eye patients to decide who should be referred for evaluation for SS. Ophthalmologists continue to prefer the use of traditional dry eye tests in practice, with the most common test being corneal fluorescein staining. There is an underreferral of dry eye patients for SS workups, which is contributing to the continued underdiagnosis of the disease. Most respondents felt that there was a need for an evidence-based standardized screening tool to decide which dry eye patients should be referred for SS evaluations.

  20. Factors contributing to commercial vehicle rear-end conflicts in China: A study using on-board event data recorders.

    PubMed

    Bianchi Piccinini, Giulio; Engström, Johan; Bärgman, Jonas; Wang, Xuesong

    2017-09-01

    In the last 30years, China has undergone a dramatic increase in vehicle ownership and a resulting escalation in the number of road crashes. Although crash figures are decreasing today, they remain high; it is therefore important to investigate crash causation mechanisms to further improve road safety in China. To shed more light on the topic, naturalistic driving data was collected in Shanghai as part of the evaluation of a behavior-based safety service. The data collection included instrumenting 47 vehicles belonging to a commercial fleet with data acquisition systems. From the overall sample, 91 rear-end crash or near-crash (CNC) events, triggered by 24 drivers, were used in the analysis. The CNC were annotated by three researchers, through an expert assessment methodology based on videos and kinematic variables. The results show that the main factor behind the rear-end CNC was the adoption of very small safety margins. In contrast to results from previous studies in the US, the following vehicles' drivers typically had their eyes on the road and reacted quickly in response to the evolving conflict in most events. When delayed reactions occurred, they were mainly due to driving-related visual scanning mismatches (e.g., mirror checks) rather than visual distraction. Finally, the study identified four main conflict scenarios that represent the typical development of rear-end conflicts in this data. The findings of this study have several practical applications, such as informing the specifications of in-vehicle safety measures and automated driving and providing input into the design of coaching/training procedures to improve the driving habits of drivers. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Nocturnality constrains morphological and functional diversity in the eyes of reef fishes.

    PubMed

    Schmitz, Lars; Wainwright, Peter C

    2011-11-19

    Ambient light levels are often considered to drive the evolution of eye form and function. Diel activity pattern is the main mechanism controlling the visual environment of teleost reef fish, with day-active (diurnal) fish active in well-illuminated conditions, whereas night-active (nocturnal) fish cope with dim light. Physiological optics predicts several specific evolutionary responses to dim-light vision that should be reflected in visual performance features of the eye. We analyzed a large comparative dataset on morphological traits of the eyes in 265 species of teleost reef fish in 43 different families. The eye morphology of nocturnal reef teleosts is characterized by a syndrome that indicates better light sensitivity, including large relative eye size, high optical ratio and large, rounded pupils. Improved dim-light image formation comes at the cost of reduced depth of focus and reduction of potential accommodative lens movement. Diurnal teleost reef fish, released from the stringent functional requirements of dim-light vision have much higher morphological and optical diversity than nocturnal species, with large ranges of optical ratio, depth of focus, and lens accommodation. Physical characteristics of the environment are an important factor in the evolution and diversification of the vertebrate eye. Both teleost reef fish and terrestrial amniotes meet the functional requirements of dim-light vision with a similar evolutionary response of morphological and optical modifications. The trade-off between improved dim-light vision and reduced optical diversity may be a key factor in explaining the lower trophic diversity of nocturnal reef teleosts.

  2. The role of uncertainty and reward on eye movements in a virtual driving task

    PubMed Central

    Sullivan, Brian T.; Johnson, Leif; Rothkopf, Constantin A.; Ballard, Dana; Hayhoe, Mary

    2012-01-01

    Eye movements during natural tasks are well coordinated with ongoing task demands and many variables could influence gaze strategies. Sprague and Ballard (2003) proposed a gaze-scheduling model that uses a utility-weighted uncertainty metric to prioritize fixations on task-relevant objects and predicted that human gaze should be influenced by both reward structure and task-relevant uncertainties. To test this conjecture, we tracked the eye movements of participants in a simulated driving task where uncertainty and implicit reward (via task priority) were varied. Participants were instructed to simultaneously perform a Follow Task where they followed a lead car at a specific distance and a Speed Task where they drove at an exact speed. We varied implicit reward by instructing the participants to emphasize one task over the other and varied uncertainty in the Speed Task with the presence or absence of uniform noise added to the car's velocity. Subjects' gaze data were classified for the image content near fixation and segmented into looks. Gaze measures, including look proportion, duration and interlook interval, showed that drivers more closely monitor the speedometer if it had a high level of uncertainty, but only if it was also associated with high task priority or implicit reward. The interaction observed appears to be an example of a simple mechanism whereby the reduction of visual uncertainty is gated by behavioral relevance. This lends qualitative support for the primary variables controlling gaze allocation proposed in the Sprague and Ballard model. PMID:23262151

  3. The neural mechanism for Latent (fusion maldevelopment) nystagmus.

    PubMed

    Tychsen, Lawrence; Richards, Michael; Wong, Agnes; Foeller, Paul; Bradley, Dolores; Burkhalter, Andreas

    2010-09-01

    Latent nystagmus (LN) is the by-product of fusion maldevelopment in infancy. Because fusion maldevelopment--in the form of strabismus and amblyopia--is common, LN is a prevalent form of pathologic nystagmus encountered in clinical practice. It originates as an afferent visual pathway disorder. To unravel the mechanism for LN, we studied patients and nonhuman primates with maldeveloped fusion. These experiments have revealed that loss of binocular connections within striate cortex (area V1) in the first months of life is the necessary and sufficient cause of LN. The severity of LN increases systematically with longer durations of binocular decorrelation and greater losses of V1 connections. Decorrelation durations that exceed the equivalent of 2-3 months in human development result in an LN prevalence of 100%. No manipulation of brain stem motor pathways is required. The binocular maldevelopment originating in area V1 is passed on to downstream extrastriate regions of cerebral cortex that drive conjugate gaze, notably MSTd. Conjugate gaze is stable when MSTd neurons of the right and left cerebral hemispheres have balanced binocular activity. Fusion maldevelopment in infancy causes unbalanced monocular activity. If input from one eye dominates and the other is suppressed, MSTd in one hemisphere becomes more active. Acting through downstream projections to the ipsilateral nucleus of the optic tract, the eyes are driven conjugately to that side. The unbalanced MSTd drive is evident as the nasalward gaze-holding bias of LN when viewing with either eye.

  4. Eye-size variability in deep-sea lanternfishes (Myctophidae): an ecological and phylogenetic study.

    PubMed

    de Busserolles, Fanny; Fitzpatrick, John L; Paxton, John R; Marshall, N Justin; Collin, Shaun P

    2013-01-01

    One of the most common visual adaptations seen in the mesopelagic zone (200-1000 m), where the amount of light diminishes exponentially with depth and where bioluminescent organisms predominate, is the enlargement of the eye and pupil area. However, it remains unclear how eye size is influenced by depth, other environmental conditions and phylogeny. In this study, we determine the factors influencing variability in eye size and assess whether this variability is explained by ecological differences in habitat and lifestyle within a family of mesopelagic fishes characterized by broad intra- and interspecific variance in depth range and luminous patterns. We focus our study on the lanternfish family (Myctophidae) and hypothesise that lanternfishes with a deeper distribution and/or a reduction of bioluminescent emissions have smaller eyes and that ecological factors rather than phylogenetic relationships will drive the evolution of the visual system. Eye diameter and standard length were measured in 237 individuals from 61 species of lanternfishes representing all the recognised tribes within the family in addition to compiling an ecological dataset including depth distribution during night and day and the location and sexual dimorphism of luminous organs. Hypotheses were tested by investigating the relationship between the relative size of the eye (corrected for body size) and variations in depth and/or patterns of luminous-organs using phylogenetic comparative analyses. Results show a great variability in relative eye size within the Myctophidae at all taxonomic levels (from subfamily to genus), suggesting that this character may have evolved several times. However, variability in eye size within the family could not be explained by any of our ecological variables (bioluminescence and depth patterns), and appears to be driven solely by phylogenetic relationships.

  5. Eye-Size Variability in Deep-Sea Lanternfishes (Myctophidae): An Ecological and Phylogenetic Study

    PubMed Central

    de Busserolles, Fanny; Fitzpatrick, John L.; Paxton, John R.; Marshall, N. Justin; Collin, Shaun P.

    2013-01-01

    One of the most common visual adaptations seen in the mesopelagic zone (200–1000 m), where the amount of light diminishes exponentially with depth and where bioluminescent organisms predominate, is the enlargement of the eye and pupil area. However, it remains unclear how eye size is influenced by depth, other environmental conditions and phylogeny. In this study, we determine the factors influencing variability in eye size and assess whether this variability is explained by ecological differences in habitat and lifestyle within a family of mesopelagic fishes characterized by broad intra- and interspecific variance in depth range and luminous patterns. We focus our study on the lanternfish family (Myctophidae) and hypothesise that lanternfishes with a deeper distribution and/or a reduction of bioluminescent emissions have smaller eyes and that ecological factors rather than phylogenetic relationships will drive the evolution of the visual system. Eye diameter and standard length were measured in 237 individuals from 61 species of lanternfishes representing all the recognised tribes within the family in addition to compiling an ecological dataset including depth distribution during night and day and the location and sexual dimorphism of luminous organs. Hypotheses were tested by investigating the relationship between the relative size of the eye (corrected for body size) and variations in depth and/or patterns of luminous-organs using phylogenetic comparative analyses. Results show a great variability in relative eye size within the Myctophidae at all taxonomic levels (from subfamily to genus), suggesting that this character may have evolved several times. However, variability in eye size within the family could not be explained by any of our ecological variables (bioluminescence and depth patterns), and appears to be driven solely by phylogenetic relationships. PMID:23472203

  6. Adolescent Cellphone Use While Driving: An Overview of the Literature and Promising Future Directions for Prevention.

    PubMed

    Delgado, M Kit; Wanner, Kathryn J; McDonald, Catherine

    2016-06-16

    Motor vehicle crashes are the leading cause of death in adolescents, and drivers aged 16-19 are the most likely to die in distracted driving crashes. This paper provides an overview of the literature on adolescent cellphone use while driving, focusing on the crash risk, incidence, risk factors for engagement, and the effectiveness of current mitigation strategies. We conclude by discussing promising future approaches to prevent crashes related to cellphone use in adolescents. Handheld manipulation of the phone while driving has been shown to have a 3 to 4-fold increased risk of a near crash or crash, and eye glance duration greater than 2 seconds increases crash risk exponentially. Nearly half of U.S. high school students admit to texting while driving in the last month, but the frequency of use according to vehicle speed and high-risk situations remains unknown. Several risk factors are associated with cell phone use while driving including: parental cellphone use while driving, social norms for quick responses to text messages, and higher levels of temporal discounting. Given the limited effectiveness of current mitigation strategies such as educational campaigns and legal bans, a multi-pronged behavioral and technological approach addressing the above risk factors will be necessary to reduce this dangerous behavior in adolescents.

  7. Adolescent Cellphone Use While Driving: An Overview of the Literature and Promising Future Directions for Prevention

    PubMed Central

    Delgado, M. Kit; Wanner, Kathryn J.; McDonald, Catherine

    2016-01-01

    Motor vehicle crashes are the leading cause of death in adolescents, and drivers aged 16–19 are the most likely to die in distracted driving crashes. This paper provides an overview of the literature on adolescent cellphone use while driving, focusing on the crash risk, incidence, risk factors for engagement, and the effectiveness of current mitigation strategies. We conclude by discussing promising future approaches to prevent crashes related to cellphone use in adolescents. Handheld manipulation of the phone while driving has been shown to have a 3 to 4-fold increased risk of a near crash or crash, and eye glance duration greater than 2 seconds increases crash risk exponentially. Nearly half of U.S. high school students admit to texting while driving in the last month, but the frequency of use according to vehicle speed and high-risk situations remains unknown. Several risk factors are associated with cell phone use while driving including: parental cellphone use while driving, social norms for quick responses to text messages, and higher levels of temporal discounting. Given the limited effectiveness of current mitigation strategies such as educational campaigns and legal bans, a multi-pronged behavioral and technological approach addressing the above risk factors will be necessary to reduce this dangerous behavior in adolescents. PMID:27695663

  8. Cable-driven elastic parallel humanoid head with face tracking for Autism Spectrum Disorder interventions.

    PubMed

    Su, Hao; Dickstein-Fischer, Laurie; Harrington, Kevin; Fu, Qiushi; Lu, Weina; Huang, Haibo; Cole, Gregory; Fischer, Gregory S

    2010-01-01

    This paper presents the development of new prismatic actuation approach and its application in human-safe humanoid head design. To reduce actuator output impedance and mitigate unexpected external shock, the prismatic actuation method uses cables to drive a piston with preloaded spring. By leveraging the advantages of parallel manipulator and cable-driven mechanism, the developed neck has a parallel manipulator embodiment with two cable-driven limbs embedded with preloaded springs and one passive limb. The eye mechanism is adapted for low-cost webcam with succinct "ball-in-socket" structure. Based on human head anatomy and biomimetics, the neck has 3 degree of freedom (DOF) motion: pan, tilt and one decoupled roll while each eye has independent pan and synchronous tilt motion (3 DOF eyes). A Kalman filter based face tracking algorithm is implemented to interact with the human. This neck and eye structure is translatable to other human-safe humanoid robots. The robot's appearance reflects a non-threatening image of a penguin, which can be translated into a possible therapeutic intervention for children with Autism Spectrum Disorders.

  9. Immunopathogenesis of Thyroid Eye Disease: Emerging Paradigms

    PubMed Central

    Naik, Vibhavari M; Naik, Milind N; Goldberg, Robert A; Smith, Terry J; Douglas, Raymond S

    2009-01-01

    Graves disease represents a systemic autoimmune process targeting the thyroid, orbit, and pretibial skin. The thyroid dysfunction is treatable, but no consistently effective medical therapy has yet been described for the orbital manifestations of Graves disease, also known as thyroid-associated ophthalmopathy or thyroid eye disease. Several autoantigens are potentially relevant to the pathogenesis of thyroid eye disease. Activating antibodies generated against the thyrotropin receptor can be detected in a majority of patients, and these drive hyperthyroidism. However, stimulating antibodies against the insulin-like growth factor-1 receptor (IGF-1R) may also play a role in the extra-thyroid manifestations of GD. IGF-1R is over-expressed by orbital fibroblasts derived from patients with TED, while IGF-1R+ T and IGF-1R+ B cells are considerably more frequent in GD. Actions of several cytokines and the molecular interplay peculiar to the orbit appear to provoke the inflammation, fat expansion, and deposition of excessive extracellular matrix molecules in thyroid eye disease. Based upon these new insights, several therapeutic strategies can now be proposed that, for the first time, might specifically interrupt its pathogenesis. PMID:20385333

  10. What factors influence cataract waiting list time?

    PubMed Central

    Churchill, A.; Vize, C.; Stewart, O.; Backhouse, O.

    2000-01-01

    AIMS—To determine whether there were any specific factors that influenced waiting list time (WLT) for patients undergoing cataract surgery.
METHODS—70 preoperative cataract patients were interviewed by one of the authors using a questionnaire to score visual acuity, coexisting ocular pathology and disabilities, threat to independent living/employment, and perceived visual handicap for detailed, gross, and driving vision. Individuals were analysed separately according to whether it was their first or second cataract operation.
RESULTS—The median WLT for first eye surgery was 9 months (n = 31) and 13 months for second eye surgery (n = 36). The WLT ranged from 2 to 25 months for first eyes and 0.25-18 months for second eyes. Where there was a perceived threat to independent living or employment the WLT was found to be significantly shorter than the median. A high overall score correlated with a shorter WLT. Surgical priority was also given to individuals with anisometropia >3 dioptres.
CONCLUSION—This study has demonstrated that there are specific factors that influence clinicians when prioritising patients for cataract surgery.

 PMID:10729304

  11. Driver fatigue alarm based on eye detection and gaze estimation

    NASA Astrophysics Data System (ADS)

    Sun, Xinghua; Xu, Lu; Yang, Jingyu

    2007-11-01

    The driver assistant system has attracted much attention as an essential component of intelligent transportation systems. One task of driver assistant system is to prevent the drivers from fatigue. For the fatigue detection it is natural that the information about eyes should be utilized. The driver fatigue can be divided into two types, one is the sleep with eyes close and another is the sleep with eyes open. Considering that the fatigue detection is related with the prior knowledge and probabilistic statistics, the dynamic Bayesian network is used as the analysis tool to perform the reasoning of fatigue. Two kinds of experiments are performed to verify the system effectiveness, one is based on the video got from the laboratory and another is based on the video got from the real driving situation. Ten persons participate in the test and the experimental result is that, in the laboratory all the fatigue events can be detected, and in the practical vehicle the detection ratio is about 85%. Experiments show that in most of situations the proposed system works and the corresponding performance is satisfying.

  12. Spirit Beside 'Home Plate,' Sol 1809 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11803 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11803

    NASA Mars Exploration Rover Spirit used its navigation camera to take the images assembled into this stereo, 120-degree view southward after a short drive during the 1,809th Martian day, or sol, of Spirit's mission on the surface of Mars (February 3, 2009).

    By combining images from the left-eye and right-eye sides of the navigation camera, the view appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    Spirit had driven about 2.6 meters (8.5 feet) that sol, continuing a clockwise route around a low plateau called 'Home Plate.' In this image, the rocks visible above the rovers' solar panels are on the slope at the northern edge of Home Plate.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  13. Opportunity's Surroundings on Sol 1818 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11846 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11846

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends.

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view.

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  14. Opportunity's Surroundings on Sol 1798 (Stereo)

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11850 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11850

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top.

    This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left.

    The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches).

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

    This view is presented as a cylindrical-perspective projection with geometric seam correction.

  15. Eye Tracking and Head Movement Detection: A State-of-Art Survey

    PubMed Central

    2013-01-01

    Eye-gaze detection and tracking have been an active research field in the past years as it adds convenience to a variety of applications. It is considered a significant untraditional method of human computer interaction. Head movement detection has also received researchers' attention and interest as it has been found to be a simple and effective interaction method. Both technologies are considered the easiest alternative interface methods. They serve a wide range of severely disabled people who are left with minimal motor abilities. For both eye tracking and head movement detection, several different approaches have been proposed and used to implement different algorithms for these technologies. Despite the amount of research done on both technologies, researchers are still trying to find robust methods to use effectively in various applications. This paper presents a state-of-art survey for eye tracking and head movement detection methods proposed in the literature. Examples of different fields of applications for both technologies, such as human-computer interaction, driving assistance systems, and assistive technologies are also investigated. PMID:27170851

  16. Evaluation of Dry Eye and Meibomian Gland Dysfunction in Teenagers with Myopia through Noninvasive Keratograph

    PubMed Central

    Wang, Xiu; Lu, Xiaoxiao; Yang, Jun; Wei, Ruihua; Yang, Liyuan; Zhao, Shaozhen; Wang, Xilian

    2016-01-01

    Purpose. This study aims to evaluate dry eye and ocular surface conditions of myopic teenagers by using questionnaire and clinical examinations. Methods. A total of 496 eyes from 248 myopic teenagers (7–18 years old) were studied. We administered Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp examination, and Keratograph 5M. The patients were divided into 2 groups based on OSDI dry eye standard, and their ocular surfaces and meibomian gland conditions were evaluated. Results. The tear meniscus heights of the dry eye and normal groups were in normal range. Corneal fluorescein scores were significantly higher whereas noninvasive break-up time was dramatically shorter in the dry eye group than in the normal group. All three meibomian gland dysfunction parameters (i.e., meibomian gland orifice scores, meibomian gland secretion scores, and meibomian gland dropout scores) of the dry eye group were significantly higher than those of the normal group (P < 0.0001). Conclusions. The prevalence of dry eye in myopic teenagers is 18.95%. Meibomian gland dysfunction plays an important role in dry eye in myopic teenagers. The Keratograph 5M appears to provide an effective noninvasive method for assessing ocular surface situation of myopic teenagers. PMID:26881059

  17. [Pseudophakic cystoid macular oedema].

    PubMed

    Bertelmann, T; Witteborn, M; Mennel, S

    2012-08-01

    Pseudophakic cystoid macular oedema is still a relevant clinical disease entity although major progress in modern cataract surgery has been made within the last decades. The relevance is attributed to the large number of cases that are performed each year. Even after uneventful surgery, a pseudophakic cystoid macular oedema can develop and may lead to severe and lasting visual impairments. In respect to the pathophysiology, four consecutive steps have to be considered: (i) surgical procedure-related induction and release of various inflammation mediators into the anterior chamber; (ii) removal of the physiological lens barrier between the anterior and posterior segments of the eye, leading consecutively to an increase in diffusion rate in either direction; (iii) local action of the inflammation mediators towards the macular area; and (iv) increased vitreoretinal traction due to the anteriorly oriented drive of the vitreous. To prevent the development of a pseudophakic cystoid macular oedema, systemic and ocular pathologies should be treated consequently prior to surgery. Furthermore, an individual risk profile of each patient needs to be evaluated to define the best pre- and postsurgical medical treatment. A less traumatic surgical approach can help to prevent macular oedema development additionally. The diagnosis is made by performing biomicroscopy, fluorescence angiography and optical coherence tomography as well as by evaluating the patients' major complaints. Standard operation procedures or recommended guidelines by the specialised eye associations to prevent and treat pseudophakic cystoid macular oedema are not available up to date. A synopsis of recommendations in the literature suggests a step-wise treatment regimen, including topical medical treatment on the one hand and a surgical approach on the other hand as well as a combination of both, if needed. Topical medical treatment options include the use of non-steroidal, corticosteroid and/or carbonic anhydrase inhibitor eye drops. Surgical interventions include pars plana vitrectomy. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Plasma Rich in Growth Factors for the Treatment of Dry Eye after LASIK Surgery.

    PubMed

    Sanchez-Avila, Ronald Mauricio; Merayo-Lloves, Jesus; Fernandez, Maria Laura; Rodriguez-Gutierrez, Luis Alberto; Jurado, Nancy; Muruzabal, Francisco; Orive, Gorka; Anitua, Eduardo

    2018-06-08

    The aim of this study was to evaluate the use of plasma rich in growth factors (PRGF) eye drops in patients with dry eye disease after laser-assisted in situ keratomileusis (LASIK) surgery. This is a longitudinal, retrospective, comparative, and descriptive study of 77 eyes of 42 patients with dry eye disease following LASIK surgery. This study was designed to evaluate the efficacy of PRGF treatment compared to conventional therapy (control group). Outcome measures including signs and symptoms of dry eye disease were evaluated before and after treatment. The percentage of change before and after treatment for each clinical variable measured was compared between both groups. There were 1-4 treatment cycles with PRGF eye drops (1 cycle = 6 weeks). Results showed a statistically significant improvement in the Ocular Surface Disease Index (38.12%), visual analogue scale scores for frequency (41.89%) and severity (42.47%), and the Schirmer test scores (88.98%) after PRGF treatment (p < 0.05). No adverse events were reported after PRGF treatment. These results suggest that PRGF eye drops are effective for the improvement of dry eye symptoms in patients who underwent LASIK surgery in comparison to the conventional therapy. The treatment with PRGF is an alternative for patients who suffer from postoperative dry eye. © 2018 S. Karger AG, Basel.

  19. Acquisition of neural learning in cerebellum and cerebral cortex for smooth pursuit eye movements

    PubMed Central

    Li, Jennifer X.; Medina, Javier F.; Frank, Loren M.; Lisberger, Stephen G.

    2011-01-01

    We have evaluated the emergence of neural learning in the frontal eye fields (FEFSEM) and the floccular complex of the cerebellum while monkeys learned a precisely-timed change in the direction of pursuit eye movement. For each neuron, we measured the time course of changes in neural response across a learning session that comprised at least 100 repetitions of an instructive change in target direction. In both areas, the average population learning curves tracked the behavioral changes with high fidelity, consistent with possible roles in driving learning. However, the learning curves of individual neurons sometimes bore little relation to the smooth, monotonic progression of behavioral learning. In the FEFSEM, neural learning was episodic. For individual neurons, learning appeared at different times during the learning session and sometimes disappeared by the end of the session. Different FEFSEM neurons expressed maximal learning at different times relative to the acquisition of behavioral learning. In the floccular complex, many Purkinje cells acquired learned simple-spike responses according to the same time course as behavioral learning and retained their learned responses throughout the learning session. A minority of Purkinje cells acquired learned responses late in the learning session, after behavioral learning had reached an asymptote. We conclude that learning in single neurons can follow a very different time course from behavioral learning. Both the FEFSEM and the floccular complex contain representations of multiple temporal components of learning, with different neurons contributing to learning at different times during the acquisition of a learned movement. PMID:21900551

  20. [Analysis of an ophthalmic pathology cohort of human fetal eyes with regard to interesting findings].

    PubMed

    Herwig, M C; Müller, A M; Holz, F G; Loeffler, K U

    2010-11-01

    Information on the evaluation of prenatal ocular findings is sparse. This article provides an overview of the morphology in a cohort of human fetal eyes, with particular emphasis on interesting findings. The study investigated 216 eyes from 115 human fetuses. The majority of fetal eyes presented with a regular phenotype. Rarely, unexpected findings were discovered in fetuses with or without systemic malformations. Routine evaluation of fetal eyes reveals-albeit rarely-new aspects providing further knowledge and occasionally enabling the exact classification of syndromes.

  1. Endogenous excitatory drive to the respiratory system in rapid eye movement sleep in cats.

    PubMed

    Orem, J; Lovering, A T; Dunin-Barkowski, W; Vidruk, E H

    2000-09-01

    A putative endogenous excitatory drive to the respiratory system in rapid eye movement (REM) sleep may explain many characteristics of breathing in that state, e.g. its irregularity and variable ventilatory responses to chemical stimuli. This drive is hypothetical, and determinations of its existence and character are complicated by control of the respiratory system by the oscillator and its feedback mechanisms. In the present study, endogenous drive was studied during apnoea caused by mechanical hyperventilation. We reasoned that if there was a REM-dependent drive to the respiratory system, then respiratory activity should emerge out of the background apnoea as a manifestation of the drive. Diaphragmatic muscle or medullary respiratory neuronal activity was studied in five intact, unanaesthetized adult cats who were either mechanically hyperventilated or breathed spontaneously in more than 100 REM sleep periods. Diaphragmatic activity emerged out of a background apnoea caused by mechanical hyperventilation an average of 34 s after the onset of REM sleep. Emergent activity occurred in 60 % of 10 s epochs in REM sleep and the amount of activity per unit time averaged approximately 40 % of eupnoeic activity. The activity occurred in episodes and was poorly related to pontogeniculo-occipital waves. At low CO2 levels, this activity was non-rhythmic. At higher CO2 levels (less than 0.5 % below eupnoeic end-tidal percentage CO2 levels in non-REM (NREM) sleep), activity became rhythmic. Medullary respiratory neurons were recorded in one of the five animals. Nineteen of twenty-seven medullary respiratory neurons were excited in REM sleep during apnoea. Excited neurons included inspiratory, expiratory and phase-spanning neurons. Excitation began about 43 s after the onset of REM sleep. Activity increased from an average of 6 impulses s-1 in NREM sleep to 15.5 impulses s-1 in REM sleep. Neuronal activity was non-rhythmic at low CO2 levels and became rhythmic when levels were less than 0.5 % below eupnoeic end-tidal levels in NREM sleep. The level of CO2 at which rhythmic neuronal activity developed corresponded to eupnoeic end-tidal CO2 levels in REM sleep. These results demonstrate an endogenous excitatory drive to the respiratory system in REM sleep and account for rapid and irregular breathing and the lower set-point to CO2 in that state.

  2. Family in the Public Eye

    ERIC Educational Resources Information Center

    Carr, Sarah E.

    2012-01-01

    Superintendents know they work and live in a giant fishbowl. School board members, teachers, community members and the news media have been known to scrutinize what kind of vehicle they drive, who they socialize with outside of work, whether they drink alcohol, where they live and when they leave the house each morning. But when the harsh glare of…

  3. The Importance of Word Study. NetNews. Volume 7, Number 3

    ERIC Educational Resources Information Center

    Frank, Marn

    2007-01-01

    The vast majority of American-born adults are exposed to written language from a very early age. Most Americans live in a print-based society where letters and words are everywhere! Drive, walk, or bike down any American street and you will see numerous eye-catching billboards, signs, and storefronts. Our towns, cities, neighborhoods, and homes…

  4. In the eye of the beholder: individual differences in reward-drive modulate early frontocentral ERPs to angry faces.

    PubMed

    Bediou, Benoit; Eimer, Martin; d'Amato, Thierry; Hauk, Olaf; Calder, Andrew J

    2009-02-01

    Individual differences in reward-drive have been associated with increased attention toward facial signals of aggression, heightened experience of anger and vulnerability to display aggressive behaviour. Recent fMRI research suggests that these effects rely on reduced ventromedial prefrontal (and increased amygdala) response to aggressive facial displays compared with neutral and sad expressions in subjects scoring high on reward-drive. However, nothing is known about the timing of this modulation. Using event-related potentials (ERPs), we provide the first evidence that greater proneness to display hostile and aggressive behaviour (measured by high scores on the reward-drive) is associated with a reduced midline frontocentral response to aggressive faces within 200-300ms. In addition to confirming a particular interaction between anger processing and aggression related personality traits in ventromedial prefrontal brain regions, our study brings a first indication of when their interaction occurs in the brain, strengthening results from previous classical as well as functional connectivity fMRI studies.

  5. Laser dazzling impacts on car driver performance

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove; Sandberg, Stig; Hörberg, Ulf; Persson, Rolf; Berglund, Folke; Karslsson, Kjell; Öhgren, Johan; Yu, Zhaohua; Söderberg, Per

    2013-10-01

    A growing problem for the Police and Security Forces has been to prevent potentially hostile individuals to pass a checkpoint, without using lethatl violence. Therefore the question has been if there is a laser or any other strong light source that could be used as a warning and dazzling device, without lethal or long term effects. To investigate the possibilities a field trial has been performed at a motor-racing track. A green CW laser with an irradiance on the eye of maximum 0.5 MPE, as defined by ICNIRP [1] and the ANZI standard [2], was used as a dazzle source. Ten drivers have been driving with dipped headlights through a course of three lines with orange cones. In every line there has been only one gate wide enough to pass without hitting the cones. The time through the course, the choice of gates and the number of cones hit have been measured. For every second trial drive through the track, the driver was exposed to the laser dazzler. The background illuminances ranged from a thousand lux in daylight to about ten millilux in darkness. The protective effect of the sun-visor of the car was investigated. The drives visual system was carefully examined before and after experimental driving and a few weeks after the experimental driving to verify that no pathological effects, that could potentially be induced by the laser exposure, pre-existed or occurred after the laser exposure. An analysis of variance for a within subjects design has been used for evaluation. It was found that green laser light can have an obvious warning effect in daylight. Dazzling does reduce the drivers ability to make judgments and manouver the car in twilight and darkness. A sun-visor can reduce the glare and give the driver an improved control, but that perception can be unjustified. No damage to the visual system was observed.

  6. Driving simulation for evaluation and rehabilitation of driving after stroke.

    PubMed

    Akinwuntan, Abiodun Emmanuel; Wachtel, Jerry; Rosen, Peter Newman

    2012-08-01

    Driving is an important activity of daily living. Loss of driving privileges can lead to depression, decreased access to medical care, and increased healthcare costs. The ability to drive is often affected after stroke. In approximately 30% of stroke survivors, it is clear from the onset that driving will no longer be possible. Approximately 33% of survivors will be able to return to driving with little or no retraining, and 35% will require driving-related rehabilitation before they can resume safe driving again. The ability to drive is not routinely evaluated after stroke, and there is no established rehabilitation program for poststroke driving. When driving evaluation does occur, it is not always clear which tests are the most salient for accurately assessing poststroke driving ability. Investigators have examined the efficacy of various methodologies to predict driving performance after stroke and have found mixed results, with each method having unique weaknesses, including poor predictive ability, poor face validity, poor sensitivity or specificity, and limited reliability. Here we review common models of driving to gain insight into why single-construct visual or cognitive off-road measures are inadequate for evaluating driving, a complex and dynamic activity that involves timely interaction of multiple motor, visual, cognitive, and perceptual skills. We also examine the potential for driving simulators to overcome the problems currently faced in the evaluation and rehabilitation of driving after stroke. Finally, we offer suggestions for the future direction of simulator-based poststroke driving evaluation and training. Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Optic disc detection using ant colony optimization

    NASA Astrophysics Data System (ADS)

    Dias, Marcy A.; Monteiro, Fernando C.

    2012-09-01

    The retinal fundus images are used in the treatment and diagnosis of several eye diseases, such as diabetic retinopathy and glaucoma. This paper proposes a new method to detect the optic disc (OD) automatically, due to the fact that the knowledge of the OD location is essential to the automatic analysis of retinal images. Ant Colony Optimization (ACO) is an optimization algorithm inspired by the foraging behaviour of some ant species that has been applied in image processing for edge detection. Recently, the ACO was used in fundus images to detect edges, and therefore, to segment the OD and other anatomical retinal structures. We present an algorithm for the detection of OD in the retina which takes advantage of the Gabor wavelet transform, entropy and ACO algorithm. Forty images of the retina from DRIVE database were used to evaluate the performance of our method.

  8. Conjunctival impression cytology evaluation of patients with dry eye disease using scleral contact lenses.

    PubMed

    Weber, Sarah La Porta; Hazarbassanov, Rossen Mihaylov; Nasaré, Alex; Gomes, José Álvaro Pereira; Hofling-Lima, Ana Luisa

    2017-06-01

    To evaluate conjunctival impression cytology and HLADR expression changes after wearing scleral contact lenses (ScCLs) for moderate to severe dry eye disease (DED). Prospective interventional case series. Forty-one eyes from 25 patients with moderate to severe DED were evaluated for Esclera ScCL treatment. Best-corrected visual acuity (BCVA) and slit-lamp findings were assessed. Impression cytology specimens were obtained from DED patients at the baseline and after wearing ScCLs for 12 months. The impression cytology specimens were analyzed using morphological results score, and HLA-DR positive cells were detected and quantified. The values were compared to assess the IC changes after wearing ScCLs. Forty-one eyes from 25 patients were fitted with ScCLs to manage DED. The underlying diseases were Stevens-Johnson syndrome (22 eyes), Sjogren's syndrome (11 eyes), graft-versus-host disease (2 eyes), dry eye after keratomileusis (2 eyes) and undifferentiated ocular surface disease (4 eyes). The HE-PAS impression cytology score did not differ significantly before and after wearing ScCLs for 12 months in DED patients (p>0.05). The percentage of eyes expressing the HLA-DR antigen in the temporal conjunctiva after wearing ScCL for 12 months significantly increased in patients with Sjogren's syndrome (11.11% to 66.66%; p=0.0498). In groups with Stevens Johnson syndrome and other ocular surface disorders, we did not observe statistically significant differences (p>0.05). The ScCLs did not change the parameters used to evaluate inflammatory processes, which were measured using conjunctival impression cytology and HLA-DR expression, except in Sjogren syndrome, in which there was an unexpected increase in HLA expression. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. Evaluation of the onset and duration of effect of azelastine eye drops (0.05%) versus placebo in patients with allergic conjunctivitis using an allergen challenge model.

    PubMed

    Friedlaender, M H; Harris, J; LaVallee, N; Russell, H; Shilstone, J

    2000-12-01

    The trial evaluated the effectiveness of the investigational antihistaminic and antiallergic compound Azelastine Eye Drops (AZE) in the treatment of allergic conjunctivitis using an allergen challenge model. Randomized, double-blind, placebo-controlled, paired-eye study. Adults with a history of allergic conjunctivitis (>/=2 years) who were asymptomatic throughout the trial, had a positive skin test (cat dander, grass, or ragweed pollen within the last year), and had a positive conjunctival reaction (score 2+ or more for itching and redness in both eyes on a 0-4 scale) during two separate conjunctival provocation tests (CPT) before randomization. Eighty patients underwent a 2-week screening period (visits 1 and 2) that included a CPT during visit 1 to establish the allergen threshold dose and a second confirmatory CPT performed at visit 2. Eye symptom assessments for itching (evaluated by patient) and conjunctival redness (evaluated by physician) were performed 5 and 10 minutes after CPT using a 5-point scale (from 0 = none to 4+ = severe). Qualified patients were randomized to receive one drop of AZE (0.015 mg of azelastine hydrochloride) in one eye and one drop of placebo in the other eye 20 minutes before CPT at visit 3 (onset) and 8 or 10 hours before CPT at visit 4 (duration). Individual severity scores for itching (evaluated by patient) and conjunctival redness (evaluated by physician) for each eye at 3, 5, and 10 minutes after CPT at visits 3 and 4 using a 5-point scale (0 = none to 4+ = very severe). Each of the 80 randomized patients completed the trial. Mean itching and conjunctival redness scores at visit 3 (onset) were significantly lower (P: < 0.001) in the AZE-treated eyes than in the placebo-treated eyes. At visit 4 (duration), mean itching and conjunctival redness scores (P:

  10. A single-center, pilot study evaluating a novel TriHex peptide- and botanical-containing eye treatment compared to baseline.

    PubMed

    Reivitis, Alex; Karimi, Kian; Griffiths, Chester; Banayan, Ashley

    2018-04-16

    Topical treatments containing tripeptide and hexapeptide (TriHex technology) have been proven to contribute to youthful skin by clearing the extracellular matrix and stimulating collagen and elastin production. Evaluate the efficacy of a novel eye treatment containing TriHex peptides and other synergistic ingredients for the daily treatment of fine lines/crow's feet around the eyes, under eye hollowing, under eye bags, and dark circles. In this study, 10 subjects (9 female and 1 male) aged 30-60 of Fitzpatrick skin type I, II, or III were selected to use an eye treatment containing TriHex peptides and active botanicals (Alastin Restorative Eye Treatment with TriHex Technology™, ALASTIN Skincare, Inc., Carlsbad, CA) twice daily for 12 weeks. Subjects were photographed and evaluated at baseline, week 4, week 8, and week 12 by a board-certified facial plastic surgeon. Using an adjusted Griffiths scale (0 = none, best possible condition and 9 = severe, worst possible condition), subjects were evaluated on severity of fine lines/crow's feet, under eye hollowing, under eye bags, and dark circles at each visit. Subjects completed a "Subject Questionnaire" at week 4, week 8, and week 12 pertaining to the subject's observations and perceived improvement of these measures. Based on the investigator's assessments, overall improvement in periocular skin was noted for all 10 subjects. Over the course of 12 weeks, raw scores significantly decreased indicating reduction of lines/crow's feet (41% improvement), under eye hollowing (29% improvement), under eye bags (48% improvement), and dark circles (39% improvement). Based on the "Subject Questionnaire," all subjects noted overall improvement of the appearance of skin around the eyes. Based on the findings of this study, this eye treatment containing TriHex peptides and active botanicals is an effective stand-alone treatment for the rejuvenation of periocular skin. When used twice daily, this product can reduce the appearance of lines/crow's feet, under eye hollowing, under eye bags, and dark circles. © 2018 Wiley Periodicals, Inc.

  11. Age-Related Differences in Vehicle Control and Eye Movement Patterns at Intersections: Older and Middle-Aged Drivers

    PubMed Central

    Yamani, Yusuke; Horrey, William J.; Liang, Yulan; Fisher, Donald L.

    2016-01-01

    Older drivers are at increased risk of intersection crashes. Previous work found that older drivers execute less frequent glances for detecting potential threats at intersections than middle-aged drivers. Yet, earlier work has also shown that an active training program doubled the frequency of these glances among older drivers, suggesting that these effects are not necessarily due to age-related functional declines. In light of findings, the current study sought to explore the ability of older drivers to coordinate their head and eye movements while simultaneously steering the vehicle as well as their glance behavior at intersections. In a driving simulator, older (M = 76 yrs) and middle-aged (M = 58 yrs) drivers completed different driving tasks: (1) travelling straight on a highway while scanning for peripheral information (a visual search task) and (2) navigating intersections with areas potential hazard. The results replicate that the older drivers did not execute glances for potential threats to the sides when turning at intersections as frequently as the middle-aged drivers. Furthermore, the results demonstrate costs of performing two concurrent tasks, highway driving and visual search task on the side displays: the older drivers performed more poorly on the visual search task and needed to correct their steering positions more compared to the middle-aged counterparts. The findings are consistent with the predictions and discussed in terms of a decoupling hypothesis, providing an account for the effects of the active training program. PMID:27736887

  12. Awareness of driving disability in people with stroke tested in a simulator.

    PubMed

    Patomella, Ann-Helen; Kottorp, Anders; Tham, Kerstin

    2008-09-01

    The aim of this study was to explore and describe awareness of driving disability in people with driving difficulties after stroke. The study comprised a consecutive sample of 38 participants with stroke who showed difficulties in a technically advanced, interactive driving simulator. Driving ability in the simulator was measured using Performance Analysis of Driving Ability (P-Drive). Awareness of driving disability was measured using a modified version of Assessment of Awareness of Disability (AAD), measuring the discrepancy between observed driving actions and self-reported disability after a driving evaluation in a simulator. A majority of the participants (n = 36) demonstrated driving ability that was below the cut-off criterion for P-Drive. Furthermore, a majority of the items measuring awareness of driving disability were scored low, indicating that participants with stroke who did not pass a driving evaluation also had limited awareness of driving disability. A General Linear Model analysis indicated that awareness of driving disability and cognitive screening outcome explained 74% of the variance in driving ability. This study indicated that a majority of the people with stroke who fail a driving evaluation also have limited awareness of their disability, which indicates the need to address awareness in driving evaluations.

  13. Evaluation of the Tobii EyeX Eye tracking controller and Matlab toolkit for research.

    PubMed

    Gibaldi, Agostino; Vanegas, Mauricio; Bex, Peter J; Maiello, Guido

    2017-06-01

    The Tobii Eyex Controller is a new low-cost binocular eye tracker marketed for integration in gaming and consumer applications. The manufacturers claim that the system was conceived for natural eye gaze interaction, does not require continuous recalibration, and allows moderate head movements. The Controller is provided with a SDK to foster the development of new eye tracking applications. We review the characteristics of the device for its possible use in scientific research. We develop and evaluate an open source Matlab Toolkit that can be employed to interface with the EyeX device for gaze recording in behavioral experiments. The Toolkit provides calibration procedures tailored to both binocular and monocular experiments, as well as procedures to evaluate other eye tracking devices. The observed performance of the EyeX (i.e. accuracy < 0.6°, precision < 0.25°, latency < 50 ms and sampling frequency ≈55 Hz), is sufficient for some classes of research application. The device can be successfully employed to measure fixation parameters, saccadic, smooth pursuit and vergence eye movements. However, the relatively low sampling rate and moderate precision limit the suitability of the EyeX for monitoring micro-saccadic eye movements or for real-time gaze-contingent stimulus control. For these applications, research grade, high-cost eye tracking technology may still be necessary. Therefore, despite its limitations with respect to high-end devices, the EyeX has the potential to further the dissemination of eye tracking technology to a broad audience, and could be a valuable asset in consumer and gaming applications as well as a subset of basic and clinical research settings.

  14. A rating scale is a proper method to evaluate changes in quality of life due to dry eye symptoms.

    PubMed

    Xue, Wenwen; Xu, Xian; Zou, Haidong

    2018-02-07

    To determine which utility value assessment method is more suitable to evaluate changes in the quality of life due to dry eye symptoms. Dry eye outpatients with a presenting visual acuity of 20/25 or better in the worse-seeing eye were recruited. Presenting distance visual acuity, tear film break-up time, Schirmer I test and fluorescein were assessed. The severity of dry eye symptoms was assessed using the Ocular Surface Disease Index (OSDI), and utility values were measured using the time trade-off (TTO), standard gamble (SG1 and SG2) and rating scale (RS) methods. Different utility values were compared with each other. The most appropriate utility value method to evaluate quality-of-life changes solely due to dry eye symptoms is determined by calculating the correlation between the OSDI score and different utility values. A total of 104 patients were enrolled. The three sections of OSDI in the order of high to low scores were as follows: "environmental trigger," "eye discomfort" and "visual function." The utility scores measured with TTO, SG1, SG2 and RS were 0.95 ± 0.11, 0.96 ± 0.10, 0.99 ± 0.07 and 0.89 ± 0.10, respectively. The utility scores evaluated by the TTO, SG1, SG2 and RS methods were significantly different from each other (p < 0.05). Only the utility scores measured with RS were significantly correlated with the composite OSDI score, "environmental trigger" and "eye discomfort" section scores (p < 0.05). RS is more sensitive than TTO and SG for the evaluation of altered quality of life due to dry eye symptoms.

  15. Ultrasonographic Findings in Patients Examined in Cataract Detection-and-Treatment Campaigns: A Retrospective Study

    PubMed Central

    Mendes, Marcio Henrique; Betinjane, Alberto Jorge; de Sá Cavalcante, Adhele; Te Cheng, Cheng; Kara-José, Newton

    2009-01-01

    INTRODUCTION: A cataract is defined as an opacity of any portion of the lens, regardless of visual acuity. In some advanced cases of cataracts, in which good fundus visualization is not possible, an ultrasound examination provides better assessment of the posterior segment of the globe. OBJECTIVES: This study aims to evaluate the ultrasonographic records of patients with advanced cataracts who were examined during cataract campaigns. METHODS: The ultrasonographic findings obtained from 215 patients examined in cataract campaigns conducted by the Hospital das Clínicas Department of Ophthalmology of the Faculdade de Medicina da Universidade de São Paulo between the years of 2005 and 2007 were evaluated, and the utility of this exam in changing the treatment procedures was studied. RESULTS: A total of 289 eyes from 215 patients were examined. Of the eyes examined, 77.5% presented with findings in the vitreous cavity and the posterior pole. A posterior vitreous detachment with no other complications was observed in 47.4% of the eyes. The remaining 30.1% presented with eye diseases that could result in a reduced visual function after surgery. The most frequent eye diseases observed were diffuse vitreous opacity (12.1% of the eyes) and detachment of the retina (9.3% of the eyes). DISCUSSION: In many cases, the ultrasonographic evaluation of the posterior segment revealed significant anomalies that changed the original treatment plan or contra-indicated surgery. At the very least, the evaluation was useful for patient counseling. CONCLUSION: The ultrasonographic examination revealed and differentiated between eyes with cataracts and eyes with ocular abnormalities other than cataracts as the cause of poor vision, thereby indicating the importance of its use during ocular evaluation. PMID:19606238

  16. Quantitative polarization and flow evaluation of choroid and sclera by multifunctional Jones matrix optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Sugiyama, S.; Hong, Y.-J.; Kasaragod, D.; Makita, S.; Miura, M.; Ikuno, Y.; Yasuno, Y.

    2016-03-01

    Quantitative evaluation of optical properties of choroid and sclera are performed by multifunctional optical coherence tomography. Five normal eyes, five glaucoma eyes and one choroidal atrophy eye are examined. The refractive error was found to be correlated with choroidal birefringence, polarization uniformity, and flow in addition to scleral birefringence among normal eyes. The significant differences were observed between the normal and the glaucoma eyes, as for choroidal polarization uniformity, flow and scleral birefringence. An automatic segmentation algorithm of retinal pigment epithelium and chorioscleral interface based on multifunctional signals is also presented.

  17. Evaluation of Eye Irritation Potential of Solid Substance with New 3D Reconstructed Human Cornea Model, MCTT HCETM

    PubMed Central

    Jang, Won-hee; Jung, Kyoung-mi; Yang, Hye-ri; Lee, Miri; Jung, Haeng-Sun; Lee, Su-Hyon; Park, Miyoung; Lim, Kyung-Min

    2015-01-01

    The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCETM which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCETM can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines. PMID:26157556

  18. 77 FR 61610 - Interagency Coordinating Committee on the Validation of Alternative Methods Evaluation Report and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ... Chemical Eye Hazards With Fewer Animals; Availability of Report; Notice of Transmittal to Federal Agencies... (ICCVAM) test method evaluation report (TMER) that provides recommendations for identifying chemical eye... animals in a three-animal test to identify chemicals and products that are eye hazards will maintain...

  19. Attention to eye contact in the West and East: autonomic responses and evaluative ratings.

    PubMed

    Akechi, Hironori; Senju, Atsushi; Uibo, Helen; Kikuchi, Yukiko; Hasegawa, Toshikazu; Hietanen, Jari K

    2013-01-01

    Eye contact has a fundamental role in human social interaction. The special appearance of the human eye (i.e., white sclera contrasted with a coloured iris) implies the importance of detecting another person's face through eye contact. Empirical studies have demonstrated that faces making eye contact are detected quickly and processed preferentially (i.e., the eye contact effect). Such sensitivity to eye contact seems to be innate and universal among humans; however, several studies suggest that cultural norms affect eye contact behaviours. For example, Japanese individuals exhibit less eye contact than do individuals from Western European or North American cultures. However, how culture modulates eye contact behaviour is unclear. The present study investigated cultural differences in autonomic correlates of attentional orienting (i.e., heart rate) and looking time. Additionally, we examined evaluative ratings of eye contact with another real person, displaying an emotionally neutral expression, between participants from Western European (Finnish) and East Asian (Japanese) cultures. Our results showed that eye contact elicited stronger heart rate deceleration responses (i.e., attentional orienting), shorter looking times, and higher ratings of subjective feelings of arousal as compared to averted gaze in both cultures. Instead, cultural differences in the eye contact effect were observed in various evaluative responses regarding the stimulus faces (e.g., facial emotion, approachability etc.). The rating results suggest that individuals from an East Asian culture perceive another's face as being angrier, unapproachable, and unpleasant when making eye contact as compared to individuals from a Western European culture. The rating results also revealed that gaze direction (direct vs. averted) could influence perceptions about another person's facial affect and disposition. These results suggest that cultural differences in eye contact behaviour emerge from differential display rules and cultural norms, as opposed to culture affecting eye contact behaviour directly at the physiological level.

  20. Attention to Eye Contact in the West and East: Autonomic Responses and Evaluative Ratings

    PubMed Central

    Akechi, Hironori; Senju, Atsushi; Uibo, Helen; Kikuchi, Yukiko; Hasegawa, Toshikazu; Hietanen, Jari K.

    2013-01-01

    Eye contact has a fundamental role in human social interaction. The special appearance of the human eye (i.e., white sclera contrasted with a coloured iris) implies the importance of detecting another person's face through eye contact. Empirical studies have demonstrated that faces making eye contact are detected quickly and processed preferentially (i.e., the eye contact effect). Such sensitivity to eye contact seems to be innate and universal among humans; however, several studies suggest that cultural norms affect eye contact behaviours. For example, Japanese individuals exhibit less eye contact than do individuals from Western European or North American cultures. However, how culture modulates eye contact behaviour is unclear. The present study investigated cultural differences in autonomic correlates of attentional orienting (i.e., heart rate) and looking time. Additionally, we examined evaluative ratings of eye contact with another real person, displaying an emotionally neutral expression, between participants from Western European (Finnish) and East Asian (Japanese) cultures. Our results showed that eye contact elicited stronger heart rate deceleration responses (i.e., attentional orienting), shorter looking times, and higher ratings of subjective feelings of arousal as compared to averted gaze in both cultures. Instead, cultural differences in the eye contact effect were observed in various evaluative responses regarding the stimulus faces (e.g., facial emotion, approachability etc.). The rating results suggest that individuals from an East Asian culture perceive another's face as being angrier, unapproachable, and unpleasant when making eye contact as compared to individuals from a Western European culture. The rating results also revealed that gaze direction (direct vs. averted) could influence perceptions about another person's facial affect and disposition. These results suggest that cultural differences in eye contact behaviour emerge from differential display rules and cultural norms, as opposed to culture affecting eye contact behaviour directly at the physiological level. PMID:23516627

  1. Conjunctival impression cytology versus routine tear function tests for dry eye evaluation in contact lens wearers.

    PubMed

    Kumar, Prachi; Bhargava, Rahul; Arora, Yogesh C; Kaushal, Sidharth; Kumar, Manjushri

    2015-01-01

    Prolonged contact lens wear is often accompanied by dryness of the eyes. The aim of this study was to compare conjunctival impression cytology (CIC) and tear film tests such as tear film break up time (TBUT) and Schirmer test for dry eye evaluation in contact lens wearers and measure their correlation with dry eye symptoms. A case control study was done at three referral eye centers. The eyes of 230 contact lens users were compared to 250 eyes of age- and sex-matched controls. Participants were recruited based on their response to a questionnaire of dry eye symptoms, (Dry Eye Scoring System, DESS(©)) and measurements of TBUT, Schirmer test, and CIC was done. A correlation analysis between symptom severity and tear film tests was performed. Pearson's coefficient, R(2) > 0.5 was considered significant. As compared to controls (r (2) = 0.010), Nelson grade correlated significantly with dry eye symptoms (r (2) = 0.765), among cases. However, there was moderate correlation between dry eye symptoms, Schirmer test, and TBUT (r (2) = 0.557 and 0.530, respectively) among cases and a weak correlation among controls (r (2) = 0.130 and 0.054, respectively). The sensitivity of TBUT was 86.4%, specificity was 82.4%, positive likelihood ratio (LR) was 4.50 [95% confidence interval (CI) 3.46-5.85)], and negative LR was 0.09. The sensitivity of the Schirmer test was 48.2%, specificity 88%, LR 2.12 (95% CI 1.48-2.96), and negative LR 0.83. CIC correlates better than Schirmer and TBUT with dry eye symptoms. It may be the most appropriate test for dry-eye evaluation in contact lens wearers.

  2. Nocturnality constrains morphological and functional diversity in the eyes of reef fishes

    PubMed Central

    2011-01-01

    Background Ambient light levels are often considered to drive the evolution of eye form and function. Diel activity pattern is the main mechanism controlling the visual environment of teleost reef fish, with day-active (diurnal) fish active in well-illuminated conditions, whereas night-active (nocturnal) fish cope with dim light. Physiological optics predicts several specific evolutionary responses to dim-light vision that should be reflected in visual performance features of the eye. Results We analyzed a large comparative dataset on morphological traits of the eyes in 265 species of teleost reef fish in 43 different families. The eye morphology of nocturnal reef teleosts is characterized by a syndrome that indicates better light sensitivity, including large relative eye size, high optical ratio and large, rounded pupils. Improved dim-light image formation comes at the cost of reduced depth of focus and reduction of potential accommodative lens movement. Diurnal teleost reef fish, released from the stringent functional requirements of dim-light vision have much higher morphological and optical diversity than nocturnal species, with large ranges of optical ratio, depth of focus, and lens accommodation. Conclusions Physical characteristics of the environment are an important factor in the evolution and diversification of the vertebrate eye. Both teleost reef fish and terrestrial amniotes meet the functional requirements of dim-light vision with a similar evolutionary response of morphological and optical modifications. The trade-off between improved dim-light vision and reduced optical diversity may be a key factor in explaining the lower trophic diversity of nocturnal reef teleosts. PMID:22098687

  3. Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics.

    PubMed

    Danion, Frederic; Mathew, James; Flanagan, J Randall

    2017-01-01

    Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance.

  4. Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics

    PubMed Central

    Mathew, James

    2017-01-01

    Abstract Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance. PMID:28680964

  5. States Change Policies with Eye to Winning Federal Grants

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2010-01-01

    As governors and state legislators gear up for a new year of budget action and policymaking, the federal Race to the Top competition is helping drive a flurry of measures nationwide aimed, at least in part, at making states stronger candidates for a slice of the $4 billion in education grants. Those efforts emerge as a priority in the 2010…

  6. A Case Study from Golden Gate University: Using Course Objectives to Facilitate Blended Learning in Shortened Courses

    ERIC Educational Resources Information Center

    Fulkerth, Robert

    2009-01-01

    This paper discusses utilizing course objectives to drive the change of existing 10-15 week undergraduate courses into 8-week courses that feature blended learning tools. To begin the redesign process, instructors and a faculty mentor revisit course objectives for currency, and with an eye toward blended course restructuring. The restructuring is…

  7. The influence of image valence on visual attention and perception of risk in drivers.

    PubMed

    Jones, M P; Chapman, P; Bailey, K

    2014-12-01

    Currently there is little research into the relationship between emotion and driving in the context of advertising and distraction. Research that has looked into this also has methodological limitations that could be affecting the results rather than emotional processing (Trick et al., 2012). The current study investigated the relationship between image valence and risk perception, eye movements and physiological reactions. Participants watched hazard perception clips which had emotional images from the international affective picture system overlaid onto them. They rated how hazardous or safe they felt, whilst eye movements, galvanic skin response and heart rate were recorded. Results suggested that participants were more aware of potential hazards when a neutral image had been shown, in comparison to positive and negative valenced images; that is, participants showed higher subjective ratings of risk, larger physiological responses and marginally longer fixation durations when viewing a hazard after a neutral image, but this effect was attenuated after emotional images. It appears that emotional images reduce sensitivity to potential hazards, and we suggest that future studies could apply these findings to higher fidelity paradigms such as driving simulators. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Mechanical Evaluation of Retinal Damage Associated With Blunt Craniomaxillofacial Trauma: A Simulation Analysis.

    PubMed

    Geng, Xiaoqi; Liu, Xiaoyu; Wei, Wei; Wang, Yawei; Wang, Lizhen; Chen, Kinon; Huo, Hongqiang; Zhu, Yuanjie; Fan, Yubo

    2018-05-01

    To evaluate retinal damage as the result of craniomaxillofacial trauma and explain its pathogenic mechanism using finite element (FE) simulation. Computed tomography (CT) images of an adult man were obtained to construct a FE skull model. A FE skin model was built to cover the outer surface of the skull model. A previously validated FE right eye model was symmetrically copied to create a FE left eye model, and both eye models were assembled to the skull model. An orbital fat model was developed to fill the space between the eye models and the skull model. Simulations of a ball-shaped object striking the frontal bone, temporal bone, brow, and cheekbones were performed, and the resulting absorption of the impact energy, intraocular pressure (IOP), and strains on the macula and ora serrata were analyzed to evaluate retinal injuries. Strain was concentrated in the macular regions (0.18 in average) of both eyes when the frontal bone was struck. The peak strain on the macula of the struck-side eye was higher than that of the other eye (>100%) when the temporal bone was struck, whereas there was little difference (<10%) between the two eyes when the brow and cheekbones were struck. Correlation analysis showed that the retinal strain time histories were highly correlated with the IOP time histories ( r > 0.8 and P = 0.000 in all simulation cases). The risk of retinal damage is variable in craniomaxillofacial trauma depending on the struck region, and the damage is highly related to IOP variation caused by indirect blunt eye trauma. This finite element eye model allows us to evaluate and understand the indirect ocular injury mechanisms in craniomaxillofacial trauma for better clinical diagnosis and treatment.

  9. En Face Spectral-Domain Optical Coherence Tomography for the Diagnosis and Evaluation of Polypoidal Choroidal Vasculopathy.

    PubMed

    Kokame, Gregg T; Shantha, Jessica G; Hirai, Kelsi; Ayabe, Julia

    2016-08-01

    To evaluate the diagnostic capability of en face spectral-domain optical coherence tomography (SD-OCT) in patients with polypoidal choroidal vasculopathy (PCV) diagnosed by indocyanine green angiography (ICGA). A retrospective, consecutive case series of 100 eyes diagnosed with PCV by ICGA were imaged with en face SD-OCT. Evaluation of the PCV complex on en face SD-OCT was performed on the ability to diagnose PCV by the characteristic configuration of the PCV complex and the extent and size of the PCV lesion. The PCV complex was better visualized on ICGA in 45 eyes, on en face SD-OCT in 44 eyes, and equally well in 11 eyes. The extent of the PCV complex was larger on en face SD-OCT in 65 eyes, larger on ICGA in 23 eyes, and equal in size in 12 eyes. En face SD-OCT images the characteristic findings of PCV and provides a noninvasive way to diagnose and treat PCV when ICGA is not available. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:737-744.]. Copyright 2016, SLACK Incorporated.

  10. Objective evaluation of the visual acuity in human eyes

    NASA Astrophysics Data System (ADS)

    Rosales, M. A.; López-Olazagasti, E.; Ramírez-Zavaleta, G.; Varillas, G.; Tepichín, E.

    2009-08-01

    Traditionally, the quality of the human vision is evaluated by a subjective test in which the examiner asks the patient to read a series of characters of different sizes, located at a certain distance of the patient. Typically, we need to ensure a subtended angle of vision of 5 minutes, which implies an object of 8.8 mm high located at 6 meters (normal or 20/20 visual acuity). These characters constitute what is known as the Snellen chart, universally used to evaluate the spatial resolution of the human eyes. The mentioned process of identification of characters is carried out by means of the eye - brain system, giving an evaluation of the subjective visual performance. In this work we consider the eye as an isolated image-forming system, and show that it is possible to isolate the function of the eye from that of the brain in this process. By knowing the impulse response of the eye´s system we can obtain, in advance, the image of the Snellen chart simultaneously. From this information, we obtain the objective performance of the eye as the optical system under test. This type of results might help to detect anomalous situations of the human vision, like the so called "cerebral myopia".

  11. How accurately do drivers evaluate their own driving behavior? An on-road observational study.

    PubMed

    Amado, Sonia; Arıkan, Elvan; Kaça, Gülin; Koyuncu, Mehmet; Turkan, B Nilay

    2014-02-01

    Self-assessment of driving skills became a noteworthy research subject in traffic psychology, since by knowing one's strenghts and weaknesses, drivers can take an efficient compensatory action to moderate risk and to ensure safety in hazardous environments. The current study aims to investigate drivers' self-conception of their own driving skills and behavior in relation to expert evaluations of their actual driving, by using naturalistic and systematic observation method during actual on-road driving session and to assess the different aspects of driving via comprehensive scales sensitive to different specific aspects of driving. 19-63 years old male participants (N=158) attended an on-road driving session lasting approximately 80min (45km). During the driving session, drivers' errors and violations were recorded by an expert observer. At the end of the driving session, observers completed the driver evaluation questionnaire, while drivers completed the driving self-evaluation questionnaire and Driver Behavior Questionnaire (DBQ). Low to moderate correlations between driver and observer evaluations of driving skills and behavior, mainly on errors and violations of speed and traffic lights was found. Furthermore, the robust finding that drivers evaluate their driving performance as better than the expert was replicated. Over-positive appraisal was higher among drivers with higher error/violation score and with the ones that were evaluated by the expert as "unsafe". We suggest that the traffic environment might be regulated by increasing feedback indicators of errors and violations, which in turn might increase the insight into driving performance. Improving self-awareness by training and feedback sessions might play a key role for reducing the probability of risk in their driving activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Transcutaneous periorbital electrical stimulation in the treatment of dry eye.

    PubMed

    Pedrotti, Emilio; Bosello, Francesca; Fasolo, Adriano; Frigo, Anna C; Marchesoni, Ivan; Ruggeri, Alfredo; Marchini, Giorgio

    2017-06-01

    To evaluate efficacy and safety of transcutaneous application of electrical current on symptoms and clinical signs of dry eye (DE). 27 patients with DE underwent transcutaneous electrostimulation with electrodes placed onto the periorbital region of both eyes and manual stimulation with a hand-piece conductor moved by the operator. Each patient underwent 12 sessions of 22 min spread over 2 months, two sessions per week in the first month and one session per week in the second month. Ocular Surface Disease Index (OSDI) questionnaire, tear break-up time (TBUT), fluorescein staining of the cornea, Schirmer I test and adverse events were evaluated at baseline, at end of treatment and at 6 and 12 months. OSDI improved from 43.0±19.2 at baseline to 25.3±22.1 at end of treatment (mean±SD, p=0.001). These effects were substantially maintained at 6-month and 12-month follow-up evaluations. Improvement of the values of TBUT was recorded for the right eye at the end of treatment (p=0.003) and found in the left eye after 12 months (p=0.02). The Oxford scores changed in both eyes at the end of treatment and at the 6-month evaluation (p<0.001), and in the right eye at the 12-month evaluation (p=0.035). Schirmer I improved significantly at the end of treatment in the left eye (p=0.001) and in both eyes at the 12-month evaluation (p=0.004 and p=0.039 for the left and right eye, respectively). A significant reduction of the use of tear substitutes was found at the end of treatment (p=0.003), and was maintained during the follow-up (p<0.001).No complications occurred and patients found the treatment satisfying. Transcutaneous electrical stimulation was shown to improve DE, both subjectively and objectively, without any adverse effects and has the potential to enlarge the armamentarium for treating DE. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Eyes Wide Shut: the impact of dim-light vision on neural investment in marine teleosts.

    PubMed

    Iglesias, Teresa L; Dornburg, Alex; Warren, Dan L; Wainwright, Peter C; Schmitz, Lars; Economo, Evan P

    2018-05-28

    Understanding how organismal design evolves in response to environmental challenges is a central goal of evolutionary biology. In particular, assessing the extent to which environmental requirements drive general design features among distantly related groups is a major research question. The visual system is a critical sensory apparatus that evolves in response to changing light regimes. In vertebrates, the optic tectum is the primary visual processing centre of the brain and yet it is unclear how or whether this structure evolves while lineages adapt to changes in photic environment. On one hand, dim-light adaptation is associated with larger eyes and enhanced light-gathering power that could require larger information processing capacity. On the other hand, dim-light vision may evolve to maximize light sensitivity at the cost of acuity and colour sensitivity, which could require less processing power. Here, we use X-ray microtomography and phylogenetic comparative methods to examine the relationships between diel activity pattern, optic morphology, trophic guild and investment in the optic tectum across the largest radiation of vertebrates-teleost fishes. We find that despite driving the evolution of larger eyes, enhancement of the capacity for dim-light vision generally is accompanied by a decrease in investment in the optic tectum. These findings underscore the importance of considering diel activity patterns in comparative studies and demonstrate how vision plays a role in brain evolution, illuminating common design principles of the vertebrate visual system. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

  14. Dynamic lens and monovision 3D displays to improve viewer comfort.

    PubMed

    Johnson, Paul V; Parnell, Jared Aq; Kim, Joohwan; Saunter, Christopher D; Love, Gordon D; Banks, Martin S

    2016-05-30

    Stereoscopic 3D (S3D) displays provide an additional sense of depth compared to non-stereoscopic displays by sending slightly different images to the two eyes. But conventional S3D displays do not reproduce all natural depth cues. In particular, focus cues are incorrect causing mismatches between accommodation and vergence: The eyes must accommodate to the display screen to create sharp retinal images even when binocular disparity drives the eyes to converge to other distances. This mismatch causes visual discomfort and reduces visual performance. We propose and assess two new techniques that are designed to reduce the vergence-accommodation conflict and thereby decrease discomfort and increase visual performance. These techniques are much simpler to implement than previous conflict-reducing techniques. The first proposed technique uses variable-focus lenses between the display and the viewer's eyes. The power of the lenses is yoked to the expected vergence distance thereby reducing the mismatch between vergence and accommodation. The second proposed technique uses a fixed lens in front of one eye and relies on the binocularly fused percept being determined by one eye and then the other, depending on simulated distance. We conducted performance tests and discomfort assessments with both techniques and compared the results to those of a conventional S3D display. The first proposed technique, but not the second, yielded clear improvements in performance and reductions in discomfort. This dynamic-lens technique therefore offers an easily implemented technique for reducing the vergence-accommodation conflict and thereby improving viewer experience.

  15. Contributions of physical and cognitive impairments to self-reported driving difficulty in chronic whiplash-associated disorders.

    PubMed

    Takasaki, Hiroshi; Treleaven, Julia; Johnston, Venerina; Jull, Gwendolen

    2013-08-15

    Cross-sectional. To conduct a preliminary analysis of the physical, cognitive, and psychological domains contributing to self-reported driving difficulty after adjusting for neck pain, dizziness, and relevant demographics in chronic whiplash-associated disorders (WAD) using hierarchical regression modeling. Pain is a risk factor for car crashes, and dizziness may affect fitness to drive. Both symptoms are common in chronic WAD and difficulty driving is a common complaint in this group. Chronic WAD is often accompanied by physical, cognitive, and psychological impairments. These impairments may contribute to self-reported driving difficulty beyond neck pain, dizziness, and relevant demographics. Forty individuals with chronic WAD participated. Dependent variables were the magnitude of self-reported driving difficulty assessed in the strategic, tactical, and operational levels of the Neck Pain Driving Index. Three models were developed to assess the contributions of independent variables (physical, cognitive, and psychological domains) to each of the 3 dependent variables after adjusting for neck pain intensity, dizziness, and driving demographics. The measures included were: physical domain-range and maximum speed of head rotation, performances during gaze stability, eye-head coordination, and visual dependency tests; cognitive domain-self-reported cognitive symptoms including fatigue and the trail making tests; and psychological domain-general stress, traumatic stress, depression, and fear of neck movements and driving. Symptom duration was relevant to driving difficulty in the strategic and tactical levels. The cognitive domain increased statistical power to estimate the strategic and operational levels (P < 0.1) beyond other contributors. The physical domain increased statistical power to estimate the tactical level (P < 0.1) beyond other contributors. Physical and cognitive impairments independently contributed to self-reported driving difficulty in chronic WAD beyond neck pain, dizziness, and symptom duration. 3.

  16. Evaluation of corneal biomechanics in patients with keratectasia following LASIK using dynamic Scheimpflug analyzer.

    PubMed

    Ueki, Ryotaro; Maeda, Naoyuki; Fuchihata, Mutsumi; Asai, Tomoko; Koh, Shizuka; Fujimoto, Hisataka; Uematsu, Masafumi; Nishida, Kohji

    2018-04-26

    To investigate the corneal biomechanics in eyes with keratectasia following LASIK using a dynamic Scheimpflug analyzer. Case-Control study. The subjects in the study included 12 eyes with keratectasia after LASIK (KE), 24 eyes with keratoconus (KC), 17 eyes without keratectasia after LASIK (LASIK), and 34 eyes with normal corneas (Normal). Corneal biomechanics of the four groups were evaluated using a dynamic Scheimpflug analyzer. Compared with Normal (7.06 ± 0.54), the radius at the highest concavity (radius, mm) of LASIK (5.96 ± 0.76), KE (4.93 ± 0.61) and KC (5.39 ± 1.02) were significantly small. The Deflection Amplitude (HCDLA, mm) of Normal (0.94 ± 0.07) was significantly lower than those of KE (1.11 ± 0.10) and KC (1.06 ± 0.16), and was not significantly different from that of LASIK (0.98 ± 0.07). There were significant differences between LASIK and KE in radius and HCDLA (P < 0.05), whereas KE and KC had no differences in these parameters. Corneal biomechanical features evaluated using the dynamic Scheimpflug analyzer suggest that biomechanical properties in eyes with keratectasia, keratoconus, and LASIK are different from those of normal eyes. Although the biomechanics in eyes with keratectasia differs from that in eyes with LASIK, it is similar to that in eyes with keratoconus.

  17. Fetal eye movements on magnetic resonance imaging.

    PubMed

    Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

    2013-01-01

    Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Dynamic SSFP sequences were acquired in 72 singleton fetuses (17-40 GW, three age groups [17-23 GW, 24-32 GW, 33-40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3-45%. In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations.

  18. Transplantation of BDNF-Secreting Mesenchymal Stem Cells Provides Neuroprotection in Chronically Hypertensive Rat Eyes

    PubMed Central

    Harper, Matthew M.; Grozdanic, Sinisa D.; Blits, Bas; Kuehn, Markus H.; Zamzow, Daniel; Buss, Janice E.; Kardon, Randy H.; Sakaguchi, Donald S.

    2011-01-01

    Purpose. To evaluate the ability of mesenchymal stem cells (MSCs) engineered to produce and secrete brain-derived neurotrophic factor (BDNF) to protect retinal function and structure after intravitreal transplantation in a rat model of chronic ocular hypertension (COH). Methods. COH was induced by laser cauterization of trabecular meshwork and episcleral veins in rat eyes. COH eyes received an intravitreal transplant of MSCs engineered to express BDNF and green fluorescent protein (BDNF-MSCs) or just GFP (GFP-MSCs). Computerized pupillometry and electroretinography (ERG) were performed to assess optic nerve and retinal function. Quantification of optic nerve damage was performed by counting retinal ganglion cells (RGCs) and evaluating optic nerve cross-sections. Results. After transplantation into COH eyes, BDNF-MSCs preserved significantly more retina and optic nerve function than GFP-MSC–treated eyes when pupil light reflex (PLR) and ERG function were evaluated. PLR analysis showed significantly better function (P = 0.03) in BDNF-MSC–treated eyes (operated/control ratio = 63.00% ± 11.39%) than GFP-MSC–treated eyes (operated/control ratio = 31.81% ± 9.63%) at 42 days after surgery. The BDNF-MSC–transplanted eyes also displayed a greater level of RGC preservation than eyes that received the GFP-MSCs only (RGC cell counts: BDNF-MSC–treated COH eyes, 112.2 ± 19.39 cells/section; GFP-MSC–treated COH eyes, 52.21 ± 11.54 cells/section; P = 0.01). Conclusions. The authors have demonstrated that lentiviral-transduced BDNF-producing MSCs can survive in eyes with chronic hypertension and can provide retina and optic nerve functional and structural protection. Transplantation of BDNF-producing stem cells may be a viable treatment strategy for glaucoma. PMID:21498611

  19. Forging Ahead

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This animation shows the front view from the Mars Exploration Rover Opportunity as it drives north towards the eastern edge of the rock outcropping near its landing site at Meridiani Planum, Mars. The movie strings together images taken over the past six martian days, or sols, of its journey, beginning with a 1 meter (3 feet) stroll away from the lander on sol 7. On the 12th sol, Opportunity drove another 3 1/2 meters (11 feet), and then, one sol later, another 1 1/2 meters (5 feet). On its way, the rover twisted and turned in a test of its driving capabilities. This movie is made up of fish-eye images taken by the rover's front hazard-identification camera.

  20. Using the intrinsic properties of silicon micro-ring modulators for characterization of RF termination

    NASA Astrophysics Data System (ADS)

    Wang, Zhao; Knights, Andrew P.

    2017-02-01

    We describe a direct experimental method to determine the effective driving voltage (Vpp) applied to a silicon photonic modulator possessing an impedance mismatch between the unterminated capacitive load and input source. This method thus permits subsequent estimation of the power consumption of an imperfectly terminated device as well as a deduction of load impedance for optimization of termination design. The capacitive load in this paper is a silicon micro-ring modulator with an integrated p-n junction acting as a phase shifter. The RF reflection under high-speed drive is directly determined from observation of the eye-diagram following measurement of the power transfer function for various junction bias.

  1. The effect of UV-blocking contact lenses as a therapy for canine chronic superficial keratitis.

    PubMed

    Denk, Nora; Fritsche, Jens; Reese, Sven

    2011-05-01

    To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial keratitus (CSK). Twenty six dogs with CSK were treated continuously with UV-blocking contact lenses for 6 months. A contact lens was placed on one eye of each dog; the other eye remained without a lens as a control eye. After this primary study, five of the dogs were further treated and they wore then contact lenses in both eyes. Continuously, all patients were concurrently treated topically with cyclosporine. The contact lenses were changed every 4 weeks and an ophthalmic examination performed. Evaluation criteria included corneal alterations as pigmentation, edema, pannus and vascularization. To determine the transmittance characteristics of the contact lenses before and after use, 32 contact lenses were measured with a UV-vis-NIR spectrophotometer. Pigmentation increased in eyes wearing lenses and in control eyes over the evaluation period of 6 months. Corneal edema increased in the eyes wearing lenses, but remained unaffected in the control eyes. A significant difference in the incidence of pannus and the extent of corneal vascularisation could not be evaluated. Adverse effects were noted in six cases (corneal edema and vascularisation, conjunctivitis, blepharospasm). All new lenses studied reduced UV-radiation to a safe level, whereas used lenses did not maintain their transmittance characteristics. No positive effect of UV-blocking contact lenses could be proven with the study design used. © 2011 American College of Veterinary Ophthalmologists.

  2. Establishment of a new in vitro test method for evaluation of eye irritancy using a reconstructed human corneal epithelial model, LabCyte CORNEA-MODEL.

    PubMed

    Katoh, Masakazu; Hamajima, Fumiyasu; Ogasawara, Takahiro; Hata, Ken-ichiro

    2013-12-01

    Finding in vitro eye irritation testing alternatives to animal testing such as the Draize eye test, which uses rabbits, is essential from the standpoint of animal welfare. It has been developed a reconstructed human corneal epithelial model, the LabCyte CORNEA-MODEL, which has a representative corneal epithelium-like structure. Protocol optimization (pre-validation study) was examined in order to establish a new alternative method for eye irritancy evaluation with this model. From the results of the optimization experiments, the application periods for chemicals were set at 1min for liquid chemicals or 24h for solid chemicals, and the post-exposure incubation periods were set at 24h for liquids or zero for solids. If the viability was less than 50%, the chemical was judged to be an eye irritant. Sixty-one chemicals were applied in the optimized protocol using the LabCyte CORNEA-MODEL and these results were evaluated in correlation with in vivo results. The predictions of the optimized LabCyte CORNEA-MODEL eye irritation test methods were highly correlated with in vivo eye irritation (sensitivity 100%, specificity 80.0%, and accuracy 91.8%). These results suggest that the LabCyte CORNEA-MODEL eye irritation test could be useful as an alternative method to the Draize eye test. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Evaluation of active and passive transport processes in corneas extracted from preserved rabbit eyes.

    PubMed

    Majumdar, Soumyajit; Hingorani, Tushar; Srirangam, Ramesh

    2010-04-01

    In vitro transcorneal permeability studies are an important screening tool in drug development. The objective of this research is to examine the feasibility of using corneas isolated from preserved rabbit eyes as a model for permeability evaluation. Eyes from male New Zealand White rabbits were used immediately or were stored overnight in phosphate-buffered saline (PBS) or Hanks balanced salt solution (HBSS) over wet ice. Integrity of isolated corneas was evaluated by measuring the TEER and by determining the permeability of paracellular and transcellular markers. Active transport was assessed by measuring transcorneal permeability of selected amino acids. Esterase activity was estimated using p-nitrophenyl assay. In all cases, corneas from freshly enucleated eyes were compared to those isolated from the day-old preserved eyes. Transcellular and paracellular passive diffusion was not affected by the storage medium and observed to be similar in the fresh and preserved eye models. However, amino acid transporters demonstrated lower functional activity in corneas excised from eyes preserved in PBS. Moreover, preserved eyes displayed almost 1.5-fold lower esterase activity in the corneal tissue. Thus, corneas isolated from day-old eyes, preserved in HBSS, closely mimics freshly excised rabbit corneas in terms of both active and passive transport characteristics but possesses slightly reduced enzymatic activity. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  4. Sensor fusion in identified visual interneurons.

    PubMed

    Parsons, Matthew M; Krapp, Holger G; Laughlin, Simon B

    2010-04-13

    Animal locomotion often depends upon stabilization reflexes that use sensory feedback to maintain trajectories and orientation. Such stabilizing reflexes are critically important for the blowfly, whose aerodynamic instability permits outstanding maneuverability but increases the demands placed on flight control. Flies use several sensory systems to drive reflex responses, and recent studies have provided access to the circuitry responsible for combining and employing these sensory inputs. We report that lobula plate VS neurons combine inputs from two optical sensors, the ocelli and the compound eyes. Both systems deliver essential information on in-flight rotations, but our neuronal recordings reveal that the ocelli encode this information in three axes, whereas the compound eyes encode in nine. The difference in dimensionality is reconciled by tuning each VS neuron to the ocellar axis closest to its compound eye axis. We suggest that this simple projection combines the speed of the ocelli with the accuracy of the compound eyes without compromising either. Our findings also support the suggestion that the coordinates of sensory information processing are aligned with axes controlling the natural modes of the fly's flight to improve the efficiency with which sensory signals are transformed into appropriate motor commands.

  5. Cavefish and the basis for eye loss.

    PubMed

    Krishnan, Jaya; Rohner, Nicolas

    2017-02-05

    Animals have colonized the entire world from rather moderate to the harshest environments, some of these so extreme that only few animals are able to survive. Cave environments present such a challenge and obligate cave animals have adapted to perpetual darkness by evolving a multitude of traits. The most common and most studied cave characteristics are the regression of eyes and the overall reduction in pigmentation. Studying these traits can provide important insights into how evolutionary forces drive convergent and regressive adaptation. The blind Mexican cavefish (Astyanax mexicanus) has emerged as a useful model to study cave evolution owing to the availability of genetic and genomic resources, and the amenability of embryonic development as the different populations remain fertile with each other. In this review, we give an overview of our current knowledge underlying the process of regressive and convergent evolution using eye degeneration in cavefish as an example.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'. © 2016 The Author(s).

  6. Cavefish and the basis for eye loss

    PubMed Central

    Krishnan, Jaya

    2017-01-01

    Animals have colonized the entire world from rather moderate to the harshest environments, some of these so extreme that only few animals are able to survive. Cave environments present such a challenge and obligate cave animals have adapted to perpetual darkness by evolving a multitude of traits. The most common and most studied cave characteristics are the regression of eyes and the overall reduction in pigmentation. Studying these traits can provide important insights into how evolutionary forces drive convergent and regressive adaptation. The blind Mexican cavefish (Astyanax mexicanus) has emerged as a useful model to study cave evolution owing to the availability of genetic and genomic resources, and the amenability of embryonic development as the different populations remain fertile with each other. In this review, we give an overview of our current knowledge underlying the process of regressive and convergent evolution using eye degeneration in cavefish as an example. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’. PMID:27994128

  7. Minimum visual requirements in different occupations in Finland.

    PubMed

    Aine, E

    1984-01-01

    In Finland the employers can individually fix the minimum visual requirements for their personnel in almost every occupation. In transportation, in police and national defence proper eyesight is regarded so important that strict visual requirements for these have been fixed by the Government. The regulations are often more close when accepting the person to the occupation than later on when working. The minimum requirements are mostly stated for visual acuity, colour perception and visual fields. In some occupations the regulations concern also the refractive error of the eyes and possible eye diseases. In aviation the regulations have been stated by the International Civil Aviation Organization ( ICAO ). The minimum visual requirements for a driving license in highway traffic are classed according to the types of motor vehicles. In railways , maritime commerce and national defence the task of the worker determines the specified regulations. The policeman must have a distant visual acuity of 0.5 without eyeglasses in both eyes and nearly normal colour perception when starting the training course.

  8. Evaluation of a Web-Based Training in Smoking Cessation Counseling Targeting U.S. Eye-Care Professionals

    ERIC Educational Resources Information Center

    Asfar, Taghrid; Lee, David J.; Lam, Byron L.; Murchison, Ann P.; Mayro, Eileen L.; Owsley, Cynthia; McGwin, Gerald; Gower, Emily W.; Friedman, David S.; Saaddine, Jinan

    2018-01-01

    Background: Smoking causes blindness-related diseases. Eye-care providers are uniquely positioned to help their patients quit smoking. Aims: Using a pre-/postevaluation design, this study evaluated a web-based training in smoking cessation counseling targeting eye-care providers. Method: The training was developed based on the 3A1R protocol:…

  9. Healthy Eyes in Schools: An Evaluation of a School and Community-Based Intervention to Promote Eye Health in Rural Timor-Leste

    ERIC Educational Resources Information Center

    Hobday, Karen; Ramke, Jacqueline; du Toit, Rènée; Pereira, Sara M.

    2015-01-01

    Objective: To assess whether there was an improvement in the knowledge, attitudes and practices of students after the Healthy Eyes in Schools Project intervention and to complete a process evaluation to inform future implementation of health promotion interventions. Design: A descriptive, mixed-methods design was used, including questionnaires and…

  10. An Application for Driver Drowsiness Identification based on Pupil Detection using IR Camera

    NASA Astrophysics Data System (ADS)

    Kumar, K. S. Chidanand; Bhowmick, Brojeshwar

    A Driver drowsiness identification system has been proposed that generates alarms when driver falls asleep during driving. A number of different physical phenomena can be monitored and measured in order to detect drowsiness of driver in a vehicle. This paper presents a methodology for driver drowsiness identification using IR camera by detecting and tracking pupils. The face region is first determined first using euler number and template matching. Pupils are then located in the face region. In subsequent frames of video, pupils are tracked in order to find whether the eyes are open or closed. If eyes are closed for several consecutive frames then it is concluded that the driver is fatigued and alarm is generated.

  11. Aberrant Behaviors and Road Accidents among Iranian Truck Drivers, 2010.

    PubMed

    Ketabi, Damon; Barkhordari, Abalfazl; Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang

    2011-01-01

    Road accidents are a social phenomenon in different communities that its infra-structural dimensions of which as well as technologic failures such as road quality, and tech-nical faults of automobiles, need to be assessed in detail. Iran has the first order in the world for deadly road accidents. This study was designed to assess the association between aberrant behaviors of truck drivers and the incidence of road accidents in Yazd, center of Iran, in 2010. This cross-sectional descriptive-analytic study was conducted on 300 truck drivers in Yazd. We used 3 questionnaires, including one for demographic data, Driver Behavior Questionnaire (DBQ), and one for drivers' self-evaluation of the of their driving. Five types of the behavior had the highest frequency: Misjudge speed of oncoming vehicle when overtaking.; Deliberately disregard the speed limits late at night or very early in the morning.; Ignore 'give way' signs, and narrowly avoid colliding with traffic having right of way.; Stuck behind a slow-moving vehicle on a two-lane highway, you are driven by frustration to try to overtake in risky circumstances.; Drive with only 'half-an-eye' on the road while looking at a map, changing a cassette or radio channel, etc. The more the driver's driv-ing was influenced by emotional and mental states the more deliberate violations and slips. Among truck drivers, safety has not developed sufficiently, and because of the dangers of road accidents both for the drivers and other people and its economic losses, the importance of the presenting some solutions is completely obvious.

  12. [Myelinated nerve fibers coexisted with epiretinal membrane in macula--case report].

    PubMed

    Swiech-Zubilewicz, Anna; Bieliński, Paweł; Dolar-Szczasny, Joanna; Zarnowski, Tomasz

    2012-01-01

    We describe a case of peripapillary myelinated retinal nerve fibers complicated by epiretinal membrane in region of macula. 72 years old man was refered to our Clinic with suspicion of retinal detachment of right eye. Visual acuity of right eye was based to 0.05, in left eye was 0.5. IOP was normal in both eyes. In biomcroscopic evaluation the slight cortical cataract was observed in both eyes. Stereoscopic evaluation of right eye revealed the presence of massive peripapillary myelinated retinal nerve fibers and epiretinal membrane in the macula. In the left eye the less intense peripapillary myelinated retinal nerve fibers were noticed as well and the macular region was unchanged. With the use of OCT examination of the retina the presence of epiretinal membrane in the right eye was confirmed. OCT in the fellow eye presented an undisturbed foveal profile without any epiretinal abnormalities. Myelinated retinal nerve fibers can be complicated by epiretinal membrane. Probably the presence of macular pathologies depends on the extensions of nerve fibers. OCT examination is very helpful to give a proper diagnosis.

  13. Subcorneal pustular dermatosis and episcleritis associated with poorly controlled ulcerative colitis.

    PubMed

    Wargo, Jeffrey J; Adams, Megan; Trevino, Julian

    2017-01-30

    A man aged 56 years with a history of ulcerative colitis (UC) status postsubtotal colectomy was hospitalised with fevers, dry cough, eye redness and a new bloody, mucoid rectal discharge. 2 months prior to admission, the dermatologist had started him on dapsone for subcorneal pustular dermatosis but did not recognise that he had recently self-discontinued mesalamine enemas, inducing a flare of his UC. After a thorough inpatient evaluation, including flexible sigmoidoscopy, active UC involving the rectal stump was determined to be driving his dermatological and ophthalmological findings. By reinstituting mesalamine enemas, control of his UC was achieved and the extraintestinal manifestations of his inflammatory bowel disease (IBD) resolved. This case illustrates the importance of careful history taking and of early recognition of extraintestinal manifestations of IBD in order to appropriately target treatment and prevent unnecessary morbidity. 2017 BMJ Publishing Group Ltd.

  14. Aircrew Eye/Respiratory Protection (AERP): 16-Hour Extended Wear Evaluation of Chemical Protective Equipment.

    DTIC Science & Technology

    1994-02-01

    Respiratory Protection (AERP) and associated clothing and equipment. Two subjects each carried out simulated tanker/transport and fighter/attack scenarios. No...AD A277 288 N•.• AL-TP-1 993-0014 ý’vI~~I~ 11~ II~I AIRCREW EYE/ RESPIRATORY PROTECTION (AERP): 16-HOUR EXTENDED WEAR EVALUATION OF R CHEMICAL...S. FUNDING NUMBERS ’Aircrew Eye/ Respiratory Protection (AERP): 16-Hour Extended PE - 62202F Wear Evaluation of Chemical Protective Equipment PR

  15. FogEye UV Sensor System Evaluation : Phase II Report

    DOT National Transportation Integrated Search

    2003-12-01

    The primary objective of the FogEye Evaluation Program is to determine whether coupled ultra-violet sources and detectors may provide enhancements to safety on the airport surface. The results of this effort will be used to complete the evaluation of...

  16. The evaluation of eye pain with a normal ocular exam.

    PubMed

    Lee, Andrew G; Brazis, Paul W

    2003-12-01

    Eye pain with or without associated head or face pain is a common complaint to the ophthalmologist. The ocular exam may reveal the etiology (e.g., corneal disease, angle closure glaucoma) but typically the exam is normal. This paper reviews the evaluation and management of eye pain with a "normal" ocular exam, including: 1) subtle findings on ocular exam; 2) transient findings on exam, and 3) no abnormal ocular findings. Ophthalmologists should be aware of the various etiologies for eye pain and the specific and distinctive features that make the diagnosis.

  17. Effect of Education Sessions of a Structured School Eye Screening Programme on Indian Schoolteachers' Knowledge and Responsibility for Children's Eye Health

    ERIC Educational Resources Information Center

    Thummalapalli, Rohit; Williams, Jachin D.; Khoshnood, Kaveh; Salchow, Daniel J.; Forster, Susan H.

    2013-01-01

    Objective: To evaluate the effect of education sessions on Indian schoolteacher awareness of childhood eye health issues, responsibility for children's eye health, and successful participation in a teacher-led eye screening health intervention programme in primary schools aimed at addressing avoidable childhood blindness in India. Design:…

  18. Evaluation of blotchy pigments in the anterior chamber angle as a sign of angle closure

    PubMed Central

    Rao, Harsha L; Mungale, Sachin C; Kumbar, Tukaram; Parikh, Rajul S; Garudadri, Chandra S

    2012-01-01

    Background: Blotchy pigments in the anterior chamber (AC) angle are considered diagnostic of primary angle closure (PAC). But there are no reports either on the prevalence of blotchy pigments in AC angles or the validity of this sign. Aims: To determine the prevalence of blotchy pigments in AC angles and to evaluate their relationship with glaucomatous optic neuropathy (GON) in eyes with occludable angles. Setting and Design: Cross-sectional, comparative study. Materials and Methods: Gonioscopy was performed in 1001 eyes of 526 subjects (245 eyes of 148 consecutive, occludable angle subjects and 756 eyes of 378 non-consecutive, open angle subjects), above 35 years of age. Quadrant-wise location of blotchy pigments was documented. Statistical Analysis: Odds of blotchy pigments in occludable angles against that in open angles were evaluated. Relationship of GON with blotchy pigments in occludable angle eyes was evaluated using a multivariate model. Results: Prevalence of blotchy pigments in occludable angles was 28.6% (95% CI, 22.9-34.3) and in open angles was 4.7% (95% CI, 3.2-6.3). Blotchy pigments were more frequently seen in inferior (16%) and superior quadrants (15%) of occludable angles, and inferior quadrant of open angles (4%). Odds of superior quadrant blotchy pigments in occludable angles were 33 times that in open angles. GON was seen in 107 occludable angle eyes. Blotchy pigments were not significantly associated with GON (odds ratio = 0.5; P = 0.1). Conclusions: Blotchy pigments were seen in 28.6% of occludable angle eyes and 4.7% of open angles eyes. Presence of blotchy pigments in the superior quadrant is more common in occludable angles. Presence of GON in occludable angle eyes was not associated with blotchy pigments. PMID:23202393

  19. Effect of chitosan-N-acetylcysteine conjugate in a mouse model of botulinum toxin B-induced dry eye.

    PubMed

    Hongyok, Teeravee; Chae, Jemin J; Shin, Young Joo; Na, Daero; Li, Li; Chuck, Roy S

    2009-04-01

    To evaluate the effect of a thiolated polymer lubricant, chitosan-N-acetylcysteine conjugate (C-NAC), in a mouse model of dry eye. Eye drops containing 0.5% C-NAC, 0.3% C-NAC, a vehicle (control group), artificial tears, or fluorometholone were applied in a masked fashion in a mouse model of induced dry eye from 3 days to 4 weeks after botulinum toxin B injection. Corneal fluorescein staining was periodically recorded. Real-time reverse transcriptase-polymerase chain reaction and immunofluorescence staining were performed at the end of the study to evaluate inflammatory cytokine expressions. Mice treated with C-NAC, 0.5%, and fluorometholone showed a downward trend that was not statistically significant in corneal staining compared with the other groups. Chitosan-NAC formulations, fluorometholone, and artificial tears significantly decreased IL-1beta (interleukin 1beta), IL-10, IL-12alpha, and tumor necrosis factor alpha expression in ocular surface tissues. The botulinum toxin B-induced dry eye mouse model is potentially useful in evaluating new dry eye treatment. Evaluation of important molecular biomarkers suggests that C-NAC may impart some protective ocular surface properties. However, clinical data did not indicate statistically significant improvement of tear production and corneal staining in any of the groups tested. Topically applied C-NAC might protect the ocular surface in dry eye syndrome, as evidenced by decreased inflammatory cytokine expression.

  20. Impact of dry eye on work productivity.

    PubMed

    Yamada, Masakazu; Mizuno, Yoshinobu; Shigeyasu, Chika

    2012-01-01

    The purpose of this study was to evaluate the impact of dry eye on work productivity of office workers, especially in terms of presenteeism. A total of 396 individuals aged ≥20 years (258 men and 138 women, mean age 43.4 ± 13.0 years) were recruited through an online survey. Data from 355 responders who did not have missing values were included in the analysis. They were classified into the following four groups according to the diagnostic status and subjective symptoms of dry eye: a definite dry eye group; a marginal dry eye group; a self-reported dry eye group; and a control group. The impact of dry eye on work productivity was evaluated using the Japanese version of the Work Limitations Questionnaire. The cost of work productivity loss associated with dry eye and the economic benefits of providing treatment for dry eye were also assessed. The degree of work performance loss was 5.65% in the definite dry eye group, 4.37% in the marginal dry eye group, 6.06% in the self-reported dry eye group, and 4.27% in the control group. Productivity in the self-reported dry eye group was significantly lower than that in the control group (P < 0.05). The annual cost of work productivity loss associated with dry eye was estimated to be USD 741 per person. Dry eye impairs work performance among office workers, which may lead to a substantial loss to industry. Management of symptoms of dry eye by providing treatment may contribute to improvement in work productivity.

  1. Efficacy of punctal occlusion in management of dry eyes after laser in situ keratomileusis for myopia.

    PubMed

    Alfawaz, Abdullah M; Algehedan, Saeed; Jastaneiah, Sabah S; Al-Mansouri, Samir; Mousa, Ahmed; Al-Assiri, Abdullah

    2014-03-01

    To evaluate the effect of punctal plug use in preventing dry eye after laser in situ keratomileusis (LASIK). A randomized clinical trial at a tertiary eye care center, Riyadh, Saudi Arabia. Participants underwent LASIK for myopia in both eyes and a lower punctal occlusion in one eye only while the other eye served as control. Both eyes received the same postoperative medications except for lubricant duration (subject eye: four times per day for one week; control eye: four times per day for 6 months). Participants were evaluated at 1 week, 2, and 6 months after surgery for signs and symptoms of dry eye. The main outcome measures were visual acuity; ocular surface parameters; and Ocular Surface Disease Index questionnaire. Seventy-eight eyes of 39 patients were included in this study. The Ocular Surface Disease Index scores of eyes with punctal plugs were better at all follow-up visits, and the differences between both eyes were statistically significant (1 week, p < 0.0001; 2 months, p < 0.0001; 6 months, p = 0.008). At the final follow-up visit, the percentage of normal eyes was higher in eyes with punctal plugs for all ocular surface parameters (Schirmer 1 test, 94.9%; tear breakup time, 77.8%; punctate epithelial keratitis score, 71.8%) compared to eyes without occlusion (Schirmer 1 test, 92.3%; tear breakup time, 58.3%; punctate epithelial keratitis score, 53.8%); however, such differences were not statistically significant. Punctal plug insertion after LASIK surgeries may minimize the need for frequent lubricant application and hence improve patient satisfaction.

  2. Intravitreal, Subretinal, and Suprachoroidal Injections: Evolution of Microneedles for Drug Delivery.

    PubMed

    Hartman, Rachel R; Kompella, Uday B

    Even though the very thought of an injection into the eye may be frightening, an estimated 6 million intravitreal (IVT) injections were made in the USA during 2016. With the introduction of new therapeutic agents, this number is expected to increase. In addition, drug products that are injectable in ocular compartments other than the vitreous humor are expected to enter the back of the eye market in the not so distant future. Besides the IVT route, some of the most actively investigated routes of invasive administration to the eye include periocular, subretinal, and suprachoroidal (SC) routes. While clinical efficacy is the driving force behind new injectable drug product development for the eye, safety is also being improved with time. In the case of IVT injections, the procedural guidelines have evolved over the years to improve patient comfort and reduce injection-related injury and infection. Similar advances are anticipated for other routes of administration of injectable products to the eye. In addition to procedural improvements, the design of needles, particularly those with smaller diameters, length, and controlled bevel angles are expected to improve overall safety and acceptance of injected ophthalmic drug products. A key development in this area is the introduction of microneedles of a length less than a millimeter that can target the SC space. In the future, needles with smaller diameters and lengths, potentially approaching nanodimensions, are expected to revolutionize ophthalmic disease management.

  3. A retrospective analysis of in vivo eye irritation, skin irritation and skin sensitisation studies with agrochemical formulations: Setting the scene for development of alternative strategies.

    PubMed

    Corvaro, M; Gehen, S; Andrews, K; Chatfield, R; Macleod, F; Mehta, J

    2017-10-01

    Analysis of the prevalence of health effects in large scale databases is key in defining testing strategies within the context of Integrated Approaches on Testing and Assessment (IATA), and is relevant to drive policy changes in existing regulatory toxicology frameworks towards non-animal approaches. A retrospective analysis of existing results from in vivo skin irritation, eye irritation, and skin sensitisation studies on a database of 223 agrochemical formulations is herein published. For skin or eye effects, high prevalence of mild to non-irritant formulations (i.e. per GHS, CLP or EPA classification) would generally suggest a bottom-up approach. Severity of erythema or corneal opacity, for skinor eye effects respectively, were the key drivers for classification, consistent with existing literature. The reciprocal predictivity of skin versus eye irritation and the good negative predictivity of the GHS additivity calculation approach (>85%) provided valuable non-testing evidence for irritation endpoints. For dermal sensitisation, concordance on data from three different methods confirmed the high false negative rate for the Buehler method in this product class. These results have been reviewed together with existing literature on the use of in vitro alternatives for agrochemical formulations, to propose improvements to current regulatory strategies and to identify further research needs. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. 45 Mbps cat's eye modulating retro-reflector link over 7 Km

    NASA Astrophysics Data System (ADS)

    Rabinovich, W. S.; Mahon, R.; Goetz, P. G.; Swingen, L.; Murphy, J.; Ferraro, M.; Burris, R.; Suite, M.; Moore, C. I.; Gilbreath, G. C.; Binari, S.

    2006-09-01

    Modulating retro-reflectors (MRR) allow free space optical links with no need for pointing, tracking or a laser on one end of the link. They work by coupling a passive optical retro-reflector with an optical modulator. The most common kind of MRR uses a corner cube retro-reflector. These devices must have a modulator whose active area is as large as the area of the corner cube. This limits the ability to close longer range high speed links because the large aperture need to return sufficient light implies a large modulator capacitance. To overcome this limitation we developed the concept of a cat's eye MRR. Cat's eye MRRs place the modulator in the focal plane of a lens system designed to passively retro-reflect light. Because the light focuses onto the modulator, a small, low capacitance, modulator can be used with a large optical aperture. However, the position of the focal spot varies with the angle of incidence so an array of modulators must be placed in the focal plane, In addition, to avoid having to drive all the modulator pixels, an angle of arrival sensor must be used. We discuss several cat's eye MRR systems with near diffraction limited performance and bandwidths of 45 Mbps. We also discuss a link to a cat's eye MRR over a 7 Km range.

  5. 75 FR 20853 - National Eye Institute; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Eye Institute... unwarranted invasion of personal privacy. Name of Committee: National Eye Institute Special Emphasis Panel, Immunosuppression for Eye Diseases. Date: April 20, 2010. Time: 3 p.m. to 4 p.m. Agenda: To review and evaluate...

  6. Mechanistic-based non-animal assessment of eye toxicity: Inflammatory profile of human keratinocytes cells after exposure to eye damage/irritant agents.

    PubMed

    da Silva, Artur Christian Garcia; Chialchia, Adrienny Rodrigues; de Ávila, Renato Ivan; Valadares, Marize Campos

    2018-06-25

    Eye toxicity is a mandatory parameter in human risk and safety evaluation for products including chemicals, pesticides, medicines and cosmetics. Historically, this endpoint has been evaluated using the Draize rabbit eye test, an in vivo model that was never formally validated. Due to advances in scientific knowledge, economic and ethical issues, non-animal methods based on mechanisms of toxicity are being developed and validated for increasing the capability of these models to predict eye toxicity. In this study, the Cytometric Bead Array (CBA) and ELISA assays were used to evaluate the inflammatory cytokine profile produced by HaCaT human keratinocytes after exposure to chemicals with different UN GHS eye toxicity classifications, aiming to stablish a correlation between inflammatory endpoints and eye toxicity (damage/irritation) potential. As a first step, cytotoxic profile of the chemicals, including 3 non-irritants and 10 eye toxicants (GHS Category 1, 2A and 2B), was evaluated after 24 h exposure using MTT assay and Inhibitory Concentration of 20% of cell viability (IC 20 ) was calculated for each chemical. Then, the cells were exposed to these chemicals at IC 20 for 24 h and supernatants and cell lysates were analyzed by CBA assay for quantification of the following cytokines: IL-6, IL-8, IL-10, IL-1β, TNF and IL-12p70. Regarding cytotoxicity evaluation, chemicals showed different cytotoxicity profiles and data demonstrated no correlation with their UN GHS classification. Among the cytokines evaluated, IL-1β production has changed after exposure and such alterations were confirmed by quantification employing ELISA method. The higher intracellular levels of IL-1β were found in GHS Category 1 chemicals, followed by Category 2A and 2B, while non irritants did not induce such increase. Thus, these findings show that IL-1β measurement, using HaCaT model, can be a considerable biomarker to identify chemicals according to their potential in promote eye toxicity, differentiating damage from irritation potential. Copyright © 2018. Published by Elsevier B.V.

  7. Peripheral refraction with eye and head rotation with contact lenses.

    PubMed

    Lopes-Ferreira, Daniela P; Neves, Helena I F; Faria-Ribeiro, Miguel; Queirós, António; Fernandes, Paulo R B; González-Méijome, José M

    2015-04-01

    To evaluate the impact of eye and head rotation in the measurement of peripheral refraction with an open-field autorefractometer in myopic eyes wearing two different center-distance designs of multifocal contact lenses (MFCLs). Nineteen right eyes from 19 myopic patients (average central M ± SD = -2.67 ± 1.66 D) aged 20-27 years (mean ± SD = 23.2 ± 3.3 years) were evaluated using a Grand-Seiko autorefractometer. Patients were fitted with one multifocal aspheric center-distance contact lens (Biofinity Multifocal D(®)) and with one multi-concentric MFCL (Acuvue Oasys for Presbyopia). Axial and peripheral refraction were evaluated by eye rotation and by head rotation under naked eye condition and with each MFCL fitted randomly and in independent sessions. For the naked eye, refractive pattern (M, J0 and J45) across the central 60° of the horizontal visual field values did not show significant changes measured by rotating the eye or rotating the head (p > 0.05). Similar results were obtained wearing the Biofinity D, for both testing methods, no obtaining significant differences to M, J0 and J45 values (p > 0.05). For Acuvue Oasys for presbyopia, also no differences were found when comparing measurements obtained by eye and head rotation (p > 0.05). Multivariate analysis did not showed a significant interaction between testing method and lens type neither with measuring locations (MANOVA, p > 0.05). There were significant differences in M and J0 values between naked eyes and each MFCL. Measurements of peripheral refraction by rotating the eye or rotating the head in myopic patients wearing dominant design or multi-concentric multifocal silicone hydrogel contact lens are comparable. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  8. The fate of eyes with wet AMD beyond four years of anti-VEGF therapy.

    PubMed

    Garweg, Justus G; Zirpel, Johanna J; Gerhardt, Christin; Pfister, Isabel B

    2018-04-01

    Real-life studies on long-term functional outcome of anti-VEGF treatment for wet age-related macular degeneration (wAMD) are limited. We therefore assessed the 10-year outcomes in our patients. In this retrospective study, all patients with newly diagnosed wAMD that had received minimally three intravitreal injections between 2007 and 2012 and a follow-up of ≥48 months were included. Primary outcome measure was the evolution of best-corrected visual acuity (BCVA) over time. For qualitative, quantitative and longitudinal data, Pearson's chi 2 test, the Mann-Whitney U-test and Wilcoxon's signed-rank test were applied at a significance level of p < 0.05. Of 267 eyes (219 patients) with newly diagnosed wAMD treated during this period, 104 eyes (104 patients) had been followed for at least 48 months and were included. Fifty-nine eyes (57.8%) after 7 years were still under active treatment, 29 eyes (25.0%) had interrupted treatment [mean follow-up 7.5 years (4.0-10.1; SD 1.6)], whereas 16 patients had died. BCVA stabilized at -7.3 to -11.9 letters after 3-10 years of follow-up with a mean of 2.8 injections (median; 3.0, SD 1.0; 1-5) and 5.1 visits per year. In two thirds of eyes, treatment was switched to aflibercept or corticosteroid combinations without bearing on functional outcomes. Thirty-seven percent (37%) of eyes maintained driving vision for up to 10 years. Beyond 3 years of treatment, functional stability was maintained for up to 10 years. Further improvement of long-term outcomes might have required a more intensive treatment in the early phase.

  9. Human short-latency ocular vergence responses produced by interocular velocity differences

    PubMed Central

    Sheliga, B. M.; Quaia, C.; FitzGibbon, E. J.; Cumming, B. G.

    2016-01-01

    We studied human short-latency vergence eye movements to a novel stimulus that produces interocular velocity differences without a changing disparity signal. Sinusoidal luminance gratings moved in opposite directions (left vs. right; up vs. down) in the two eyes. The grating seen by each eye underwent ¼-wavelength shifts with each image update. This arrangement eliminated changing disparity cues, since the phase difference between the eyes alternated between 0° and 180°. We nevertheless observed robust short-latency vergence responses (VRs), whose sign was consistent with the interocular velocity differences (IOVDs), indicating that the IOVD cue in isolation can evoke short-latency VRs. The IOVD cue was effective only when the images seen by the two eyes overlapped in space. We observed equally robust VRs for opposite horizontal motions (left in one eye, right in the other) and opposite vertical motions (up in one eye, down in the other). Whereas the former are naturally generated by objects moving in depth, the latter are not part of our normal experience. To our knowledge, this is the first demonstration of a behavioral consequence of vertical IOVD. This may reflect the fact that some neurons in area MT are sensitive to these motion signals (Czuba, Huk, Cormack, & Kohn, 2014). VRs were the strongest for spatial frequencies in the range of 0.35–1 c/°, much higher than the optimal spatial frequencies for evoking ocular-following responses observed during frontoparallel motion. This suggests that the two motion signals are detected by different neuronal populations. We also produced IOVD using moving uncorrelated one-dimensional white-noise stimuli. In this case the most effective stimuli have low speed, as predicted if the drive originates in neurons tuned to high spatial frequencies (Sheliga, Quaia, FitzGibbon, & Cumming, 2016). PMID:27548089

  10. Where We Look When We Drive with or without Active Steering Wheel Control

    PubMed Central

    Mars, Franck; Navarro, Jordan

    2012-01-01

    Current theories on the role of visuomotor coordination in driving agree that active sampling of the road by the driver informs the arm-motor system in charge of performing actions on the steering wheel. Still under debate, however, is the nature of visual cues and gaze strategies used by drivers. In particular, the tangent point hypothesis, which states that drivers look at a specific point on the inside edge line, has recently become the object of controversy. An alternative hypothesis proposes that drivers orient gaze toward the desired future path, which happens to be often situated in the vicinity of the tangent point. The present study contributed to this debate through the analyses of the distribution of gaze orientation with respect to the tangent point. The results revealed that drivers sampled the roadway in the close vicinity of the tangent point rather than the tangent point proper. This supports the idea that drivers look at the boundary of a safe trajectory envelop near the inside edge line. Furthermore, the study investigated for the first time the reciprocal influence of manual control on gaze control in the context of driving. This was achieved through the comparison of gaze behavior when drivers actively steered the vehicle or when steering was performed by an automatic controller. The results showed an increase in look-ahead fixations in the direction of the bend exit and a small but consistent reduction in the time spent looking in the area of the tangent point when steering was passive. This may be the consequence of a change in the balance between cognitive and sensorimotor anticipatory gaze strategies. It might also reflect bidirectional coordination control between the eye and arm-motor systems, which goes beyond the common assumption that the eyes lead the hands when driving. PMID:22928043

  11. Improving Night Time Driving Safety Using Vision-Based Classification Techniques

    PubMed Central

    Chien, Jong-Chih; Chen, Yong-Sheng; Lee, Jiann-Der

    2017-01-01

    The risks involved in nighttime driving include drowsy drivers and dangerous vehicles. Prominent among the more dangerous vehicles around at night are the larger vehicles which are usually moving faster at night on a highway. In addition, the risk level of driving around larger vehicles rises significantly when the driver’s attention becomes distracted, even for a short period of time. For the purpose of alerting the driver and elevating his or her safety, in this paper we propose two components for any modern vision-based Advanced Drivers Assistance System (ADAS). These two components work separately for the single purpose of alerting the driver in dangerous situations. The purpose of the first component is to ascertain that the driver would be in a sufficiently wakeful state to receive and process warnings; this is the driver drowsiness detection component. The driver drowsiness detection component uses infrared images of the driver to analyze his eyes’ movements using a MSR plus a simple heuristic. This component issues alerts to the driver when the driver’s eyes show distraction and are closed for a longer than usual duration. Experimental results show that this component can detect closed eyes with an accuracy of 94.26% on average, which is comparable to previous results using more sophisticated methods. The purpose of the second component is to alert the driver when the driver’s vehicle is moving around larger vehicles at dusk or night time. The large vehicle detection component accepts images from a regular video driving recorder as input. A bi-level system of classifiers, which included a novel MSR-enhanced KAZE-base Bag-of-Features classifier, is proposed to avoid false negatives. In both components, we propose an improved version of the Multi-Scale Retinex (MSR) algorithm to augment the contrast of the input. Several experiments were performed to test the effects of the MSR and each classifier, and the results are presented in experimental results section of this paper. PMID:28946643

  12. Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish: response to Borowsky (2013).

    PubMed

    Yoshizawa, Masato; O'Quin, Kelly E; Jeffery, William R

    2013-07-11

    Vibration attraction behavior (VAB) is the swimming of fish toward an oscillating object, a behavior that is likely adaptive because it increases foraging efficiency in darkness. VAB is seen in a small proportion of Astyanax surface-dwelling populations (surface fish) but is pronounced in cave-dwelling populations (cavefish). In a recent study, we identified two quantitative trait loci for VAB on Astyanax linkage groups 2 and 17. We also demonstrated that a small population of superficial neuromast sensors located within the eye orbit (EO SN) facilitate VAB, and two quantitative trait loci (QTL) were identified for EO SN that were congruent with those for VAB. Finally, we showed that both VAB and EO SN are negatively correlated with eye size, and that two (of several) QTL for eye size overlap VAB and EO SN QTLs. From these results, we concluded that the adaptive evolution of VAB and EO SN has contributed to the indirect loss of eyes in cavefish, either as a result of pleiotropy or tight physical linkage of the mutations underlying these traits. In a subsequent commentary, Borowsky argues that there is poor experimental support for our conclusions. Specifically, Borowsky states that: (1) linkage groups (LGs) 2 and 17 harbor QTL for many traits and, therefore, no evidence exists for an exclusive interaction among the overlapping VAB, EO SN and eye size QTL; (2) some of the QTL we identified are too broad (>20 cM) to support the hypothesis of correlated evolution due to pleiotropy or hitchhiking; and (3) VAB is unnecessary to explain the indirect evolution of eye-loss since the negative polarity of numerous eye QTL is consistent with direct selection against eyes. Borowsky further argues that (4) it is difficult to envision an evolutionary scenario whereby VAB and EO SN drive eye loss, since the eyes must first be reduced in order to increase the number of EO SN and, therefore, VAB. In this response, we explain why the evidence of one trait influencing eye reduction is stronger for VAB than other traits, and provide further support for a scenario whereby elaboration of VAB in surface fish may precede complete eye-loss.

  13. DETECTION OF MICROVASCULAR CHANGES IN EYES OF PATIENTS WITH DIABETES BUT NOT CLINICAL DIABETIC RETINOPATHY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

    PubMed

    de Carlo, Talisa E; Chin, Adam T; Bonini Filho, Marco A; Adhi, Mehreen; Branchini, Lauren; Salz, David A; Baumal, Caroline R; Crawford, Courtney; Reichel, Elias; Witkin, Andre J; Duker, Jay S; Waheed, Nadia K

    2015-11-01

    To evaluate the ability of optical coherence tomography angiography to detect early microvascular changes in eyes of diabetic individuals without clinical retinopathy. Prospective observational study of 61 eyes of 39 patients with diabetes mellitus and 28 control eyes of 22 age-matched healthy subjects that received imaging using optical coherence tomography angiography between August 2014 and March 2015. Eyes with concomitant retinal, optic nerve, and vitreoretinal interface diseases and/or poor-quality images were excluded. Foveal avascular zone size and irregularity, vessel beading and tortuosity, capillary nonperfusion, and microaneurysm were evaluated. Foveal avascular zone size measured 0.348 mm² (0.1085-0.671) in diabetic eyes and 0.288 mm² (0.07-0.434) in control eyes (P = 0.04). Foveal avascular zone remodeling was seen more often in diabetic than control eyes (36% and 11%, respectively; P = 0.01). Capillary nonperfusion was noted in 21% of diabetic eyes and 4% of control eyes (P = 0.03). Microaneurysms and venous beading were noted in less than 10% of both diabetic and control eyes. Both diabetic and healthy control eyes demonstrated tortuous vessels in 21% and 25% of eyes, respectively. Optical coherence tomography angiography was able to image foveal microvascular changes that were not detected by clinical examination in diabetic eyes. Changes to the foveal avascular zone and capillary nonperfusion were more prevalent in diabetic eyes, whereas vessel tortuosity was observed with a similar frequency in normal and diabetic eyes. Optical coherence tomography angiography may be able to detect diabetic eyes at risk of developing retinopathy and to screen for diabetes quickly and noninvasively before the systemic diagnosis is made.

  14. The Evaluation of Anatomic and Functional Changes in Unilateral Moderate Amblyopic Eyes Using Optical Coherence Tomography and Pupil Cycle Time.

    PubMed

    Kusbeci, Tuncay; Karti, Omer; Karahan, Eyyup; Oguztoreli, Mustafa

    2017-12-01

    To investigate whether macular anatomic structure and afferent visual system function differ among amblyopic eyes, non-amblyopic fellow eyes, and controls, using spectral-domain optical coherence tomography (SD-OCT), and pupil cycle time (PCT). This observational, cross-sectional study included 30 patients with unilateral amblyopia and 30 healthy subjects. Optical coherence tomography (OCT) and pupil cycle time (PCT) were used to evaluate patients with unilateral amblyopia and were compared with their non-amblyopic fellow eyes and age- and gender-matched healthy eyes (30 participants). The amblyopic eyes were separated into two groups: anisometropic amblyopia (n = 16) and strabismic amblyopia (n = 14). OCT maps were used to calculate central macular thickness (CMT), retinal nerve fiber layer thickness (RNFLT), and ganglion cell-inner plexiform layer (GC-IPL) thickness. The average RNFLT, GC-IPL thickness, and CMT did not show any significant differences among the amblyopic eyes, non-amblyopic fellow eyes and controls (p > 0.05, Kruskal-Wallis test). Mean PCT was 773.57 ± 64 msn in strabismic eyes, 771.25 ± 58 msn in anisometropic eyes, 778.00 ± 72 msn in non-amblyopic fellow eyes, and 774.75 ± 69 msn in control eyes. The differences among the amblyopic eyes, its fellow and control eyes were not statistically significant (p > 0.05, Kruskal-Wallis test). In this study, we investigated morphological and functional differences among amblyopic eyes, non-amblyopic fellow eyes and controls by using SD-OCT and PCT. We did not find anatomical or functional changes in amblyopic eyes.

  15. The correlation between subordinate fish eye colour and received attacks: a negative social feedback mechanism for the reduction of aggression during the formation of dominance hierarchies.

    PubMed

    Miyai, Caio A; Carretero Sanches, Fábio H; Costa, Tânia M; Colpo, Karine Delevati; Volpato, Gilson L; Barreto, Rodrigo E

    2011-12-01

    Eye darkening has been linked to social status in fish. The subordinate's eyes darken, while the eyes of the dominant fish become pale. Although this phenomenon has been described in salmonid fishes and in the African cichlid Nile tilapia Oreochromis niloticus, it is unclear whether eye darkening correlates with a reduction in aggressive behaviour. Thus, we evaluated the link between social status and eye darkening. We evaluated whether the eye colours of subordinate fish correlate with the frequency of received attacks in a neotropical fish, the pearl cichlid Geophagus brasiliensis. We paired pearl cichlids and quantified both the aggressive behaviour and the eye darkening of each fish. As has been described for Nile tilapia and Atlantic salmon, a clear-cut hierarchical relationship formed, where dominance and subordination were associated with pale and dark eye colours, respectively. Initially, eye colour darkening was positively correlated with the frequency of received attacks; however, a negative association occurred following eye darkening, in which the intensity of aggressive interactions decreased. Thus, fish that initially received a high number of attacks signalled subordination more rapidly and intensely (rapid and dramatic eye darkening), thereby inducing a negative social feedback mechanism that led to reduced aggression. Copyright © 2011 Elsevier GmbH. All rights reserved.

  16. Discriminating anisometropic amblyopia from myopia based on interocular inhibition

    PubMed Central

    Jia, Wuli; Zhou, Jiawei; Lu, Zhong-Lin; Lesmes, Luis A.; Huang, Chang-Bing

    2016-01-01

    Amblyopia screening during childhood is critical for early detection and successful treatment. In the current study, we develop and evaluate a screening method that exploits the imbalanced interocular inhibition between amblyopic and fellow eyes. In nineteen subjects with anisometropic amblyopia and twenty-two age-matched subjects with myopia, we measured the area under the contrast sensitivity functions (AUCSFs) in eight monocular conditions defined by tested eye (left, right), patching of the untested eye (translucent, opaque), and refractive status (corrected, uncorrected). For each test eye, we defined the inhibition index as the ratio between AUCSF values obtained in the translucent and opaque patching conditions of the untested eye. To evaluate the screening potential of the inhibition index, we compared results from patients with amblyopia and myopia. With and without optical correction, the index was significantly lower in the amblyopic eye than in the fellow eye of the amblyopic subjects and both eyes of the myopic subjects. No significant difference was found among the two eyes of the myopic subjects and the fellow eyes of the amblyopic subjects. With the inhibition index as the predictor, a logistic regression model successfully discriminated amblyopic eyes from myopic eyes with 100% accuracy in the uncorrected condition. In the corrected condition, with the inhibition index and interocular visual acuity difference as predictors, amblyopic eyes were likewise discriminated from myopic eyes with 100% accuracy. This pattern of CSF changes, caused by the different patching modes of the untested eye, provides a potential CSF signature to discriminate anisometropic amblyopia from myopia. PMID:25701741

  17. An eye tracking system for monitoring face scanning patterns reveals the enhancing effect of oxytocin on eye contact in common marmosets.

    PubMed

    Kotani, Manato; Shimono, Kohei; Yoneyama, Toshihiro; Nakako, Tomokazu; Matsumoto, Kenji; Ogi, Yuji; Konoike, Naho; Nakamura, Katsuki; Ikeda, Kazuhito

    2017-09-01

    Eye tracking systems are used to investigate eyes position and gaze patterns presumed as eye contact in humans. Eye contact is a useful biomarker of social communication and known to be deficient in patients with autism spectrum disorders (ASDs). Interestingly, the same eye tracking systems have been used to directly compare face scanning patterns in some non-human primates to those in human. Thus, eye tracking is expected to be a useful translational technique for investigating not only social attention and visual interest, but also the effects of psychiatric drugs, such as oxytocin, a neuropeptide that regulates social behavior. In this study, we report on a newly established method for eye tracking in common marmosets as unique New World primates that, like humans, use eye contact as a mean of communication. Our investigation was aimed at characterizing these primates face scanning patterns and evaluating the effects of oxytocin on their eye contact behavior. We found that normal common marmosets spend more time viewing the eyes region in common marmoset's picture than the mouth region or a scrambled picture. In oxytocin experiment, the change in eyes/face ratio was significantly greater in the oxytocin group than in the vehicle group. Moreover, oxytocin-induced increase in the change in eyes/face ratio was completely blocked by the oxytocin receptor antagonist L-368,899. These results indicate that eye tracking in common marmosets may be useful for evaluating drug candidates targeting psychiatric conditions, especially ASDs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. ASSOCIATION BETWEEN VISUAL FUNCTION AND SUBRETINAL DRUSENOID DEPOSITS IN NORMAL AND EARLY AGE-RELATED MACULAR DEGENERATION EYES.

    PubMed

    Neely, David; Zarubina, Anna V; Clark, Mark E; Huisingh, Carrie E; Jackson, Gregory R; Zhang, Yuhua; McGwin, Gerald; Curcio, Christine A; Owsley, Cynthia

    2017-07-01

    To examine the association between subretinal drusenoid deposits (SDDs) identified by multimodal retinal imaging and visual function in older eyes with normal macular health or in the earliest phases of age-related macular degeneration (AMD). Age-related macular degeneration status for each eye was defined according to the Age-Related Eye Disease Study (AREDS) 9-step classification system (normal = Step 1, early AMD = Steps 2-4) based on color fundus photographs. Visual functions measured were best-corrected photopic visual acuity, contrast and light sensitivity, mesopic visual acuity, low-luminance deficit, and rod-mediated dark adaptation. Subretinal drusenoid deposits were identified through multimodal imaging (color fundus photographs, infrared reflectance and fundus autofluorescence images, and spectral domain optical coherence tomography). The sample included 1,202 eyes (958 eyes with normal health and 244 eyes with early AMD). In normal eyes, SDDs were not associated with any visual function evaluated. In eyes with early AMD, dark adaptation was markedly delayed in eyes with SDDs versus no SDD (a 4-minute delay on average), P = 0.0213. However, this association diminished after age adjustment, P = 0.2645. Other visual functions in early AMD eyes were not associated with SDDs. In a study specifically focused on eyes in normal macular health and in the earliest phases of AMD, early AMD eyes with SDDs have slower dark adaptation, largely attributable to the older ages of eyes with SDD; they did not exhibit deficits in other visual functions. Subretinal drusenoid deposits in older eyes in normal macular health are not associated with any visual functions evaluated.

  19. Detection of Potentially Severe Retinopathy of Prematurity by Remote Image Grading.

    PubMed

    Quinn, Graham E; Ying, Gui-Shuang; Pan, Wei; Baumritter, Agnieshka; Daniel, Ebenezer

    2017-09-01

    Telemedicine in retinopathy of prematurity (ROP) has the potential for delivering timely care to premature infants at risk for serious ROP. To describe the characteristics of eyes at risk for ROP to provide insights into what types of ROP are most easily detected early by image grading. Secondary analysis of eyes with referral-warranted (RW) ROP (stage 3 ROP, zone I ROP, plus disease) on diagnostic examination from the Telemedicine Approaches to Evaluating Acute-Phase Retinopathy of Prematurity (e-ROP) study was conducted from May 1, 2011, to October 31, 2013, in 1257 premature infants with birth weights less than 1251 g in 13 neonatal units in North America. Data analysis was performed between February 1, 2016, and June 5, 2017. Serial imaging sessions with concurrent diagnostic examinations for ROP. Time of detecting RW-ROP on image evaluation compared with clinical examination. In the e-ROP study, 246 infants (492 eyes) were included in the analysis; 138 (56.1%) were male. A total of 447 eyes had RW-ROP on diagnostic examination. Image grading in 123 infants (mean [SD] gestational age, 24.8 [1.4] weeks) detected RW-ROP earlier than diagnostic examination (early) in 191 (42.7%) eyes by about 15 days and detected RW-ROP in 123 infants (mean [SD] gestational age, 24.6 [1.5] weeks) at the same time (same) in 200 (44.7%) eyes. Most of the early eyes (153 [80.1%]) interpreted as being RW-ROP positive on imaging evaluation agreed with examination findings when the examination subsequently documented RW-ROP. At the sessions in which RW-ROP was first found by examination, stage 3 or more in 123 infants (mean [SD] gestational age, 24.8 [1.4] weeks) ROP was noted earlier on image evaluation in 151 of 191 early eyes (79.1%) and in 172 of 200 of same eyes (86.0%) (P = .08); the presence of zone I ROP was detected in 57 of 191 (29.8%) early eyes vs 64 of 200 (32.0%) same eyes (P = .90); and plus disease was noted in 30 of 191 (15.7%) early eyes and 45 of 200 (22.5%) same eyes (P = .08). In both early and same eyes, zone I and/or stage 3 ROP determined a significant proportion of RW-ROP; plus disease played a relatively minor role. In most early RW-ROP eyes, the findings were consistent with clinical examination and/or image grading at the next session. Because ROP telemedicine is used more widely, development of standard approaches and protocols is essential.

  20. Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

    PubMed Central

    Kim, M K; Lee, J L; Wee, W R; Lee, J H

    2002-01-01

    Aims: To evaluate in vivo fibroplasia and biological stability of porous polymers intended for use in the Seoul-type keratoprosthesis (S-KPro). Methods: Four porous polymers (polypropylene, two kinds of polyethylene terephthalate (PE70 and PE50), and polyurethane) were investigated. Discs of polymers were inserted into the corneal stroma of rabbits for a 2 and 5 month period. Corneal oedema and neovascularisation were evaluated. The fibroplasia and collagen deposition were examined under light and transmission electron microscopy. S-KPros, whose skirt was made of four types of polymer, were implanted into the rabbits' eyes. The retention time and complications were evaluated. Results: Neovascularisation and corneal oedema were found in all of the disc inserted eyes, but the corneal oedema subsided within 2 months in most of the eyes. The mean number of fibroblasts increased significantly in polypropylene and PE50 disc inserted eyes compared with polyurethane disc inserted eyes. Plentiful collagen deposition was also found in both polypropylene and PE50 disc inserted eyes. Mean retention time in the polypropylene SK-Pro implanted eyes was longer than that of the other eyes (20.7 weeks). The PE70 skirt induced corneal melting around the prosthesis. Conclusion: Polypropylene encourages fibroblast ingrowth and shows good biological stability when used as a skirt material in S-KPro. PMID:12084755

  1. Prevalence of Dry Eye in Uyghur and Han Ethnic Groups in Western China.

    PubMed

    Gong, Ying-Ying; Zhang, Fan; Zhou, Jin; Li, Jing; Zhang, Guang-Hui; Wang, Jun-Liang; Gu, Zhen-Sheng

    2017-06-01

    To describe and compare the prevalence and characteristics of dry eye among Han and Uyghur persons living in Kashi, the most inland city of China. A total of 1015 residents of Kashi participated in this 2013 cross-sectional study. To evaluate clinical characteristics, each subject completed (1) a dry-eye questionnaire detailing symptoms of dry eye, (2) Schirmer's I-test (SIT), (3) tear-film break-up time (BUT) test, and fluorescein staining of the cornea. Dry eye was defined as the existence of dry eye symptoms and at least two positive clinical signs. Data were analyzed using SPSS software. The prevalence and risk factors of dry eye were evaluated using a multivariate model. Overall, 282 (27.8%) of the 1015 participants were diagnosed with dry eye (95% confidence interval (CI): range, 25.5-30.1). The prevalence of dry eye among Han persons (37.9 %) (95% CI: range, 35.8-40.0) was higher than that among Uyghurs (21.8%) (95% CI: 19.6-24.0) (p < 0.05). The prevalence of dry eye was 25.6% (95% CI: range, 23.3-27.8) among men and 28.7% (95% CI: 26.5-30.9) among women (p > 0.05). Risk factors for dry eye included ethnicity, age, occupation, arthritis, and dry mouth. Our study revealed a higher prevalence of dry eye among Han than Uyghur persons in Kashi. Dry eye was significantly associated with environment and ethnicity.

  2. Chronic dry eye in PRK and LASIK: manifestations, incidence and predictive factors

    PubMed Central

    Bower, Kraig S.; Sia, Rose K.; Ryan, Denise S.; Mines, Michael J.; Dartt, Darlene A.

    2017-01-01

    Purpose To evaluate dry eye manifestations following photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and determine the incidence and predictive factors of chronic dry eye using a set of dry eye criteria. Setting Walter Reed Army Medical Center, Washington, DC, USA Methods This is a prospective non-randomized clinical study of 143 active duty U.S. Army personnel aged 29.9±5.2 years with myopia or myopic astigmatism (manifest spherical equivalent −3.83±1.96 diopters) undergoing either PRK or LASIK. Dry eye evaluation was performed pre- and postoperatively. Main outcome measures included dry eye manifestations, incidence, and predictive factors of chronic dry eye. Results Schirmer scores, corneal sensitivity, ocular surface staining, surface regularity index (SRI), and responses to dry eye questionnaire significantly changed over time after PRK. After LASIK, significant changes were observed in tear breakup time, corneal sensitivity, ocular surface staining, and responses to questionnaire. At twelve months postoperatively, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye. Regression analysis showed preoperatively lower Schirmer score will significantly influence development of chronic dry eye after PRK whereas preoperatively lower Schirmer score or higher ocular surface staining score will significantly influence the occurrence of chronic dry eye after LASIK. Conclusions Chronic dry eye is uncommon after PRK and LASIK. Ocular surface and tear film characteristics during preoperative examination may help predict chronic dry eye development in PRK and LASIK. PMID:26796443

  3. Association of IL-21 cytokine with severity of primary Sjögren syndrome dry eye.

    PubMed

    Lim, Sung A; Nam, Doo Hyun; Lee, Jee Hye; Kwok, Seung-Ki; Park, Sung-Hwan; Chung, So-Hyang

    2015-03-01

    IL-21 plays an important role in primary Sjögren syndrome (SS) pathogenesis. The purpose of this study was to evaluate IL-21 expression in tears and the conjunctiva and to analyze the impact of IL-21 on primary SS dry eyes. Eighty subjects were enrolled in this study: 30 patients with primary SS dry eye (30 eyes); 30 patients with non-SS dry eye (30 eyes), and 20 normal controls. Tear IL-21 levels were measured by flow cytometry, and IL-21 gene expression in the conjunctiva from impression cytology was evaluated by quantitative polymerase chain reaction. Ocular Surface Disease Index, tear film breakup time, Schirmer I test, and ocular surface staining scores were obtained for all patients. Primary SS dry eyes had significantly higher tear IL-21 levels than non-SS dry eyes and normal controls (P < 0.01). In addition, IL-21 gene expression in the conjunctiva was also higher in primary SS dry eyes than in non-SS dry eyes and normal controls (P < 0.01). However, there were no significant differences in IL-21 expression in tears and the conjunctiva between non-SS dry eyes and controls. The tear IL-21 level was significantly correlated with ocular surface stain scores (r = 0.54, P < 0.01) and Schirmer I test values (r = -0.23, P < 0.05) in primary SS dry eyes. Our findings suggest that severity of primary SS dry eye is associated with IL-21.

  4. Evaluation of a Risk Awareness Perception Training Program on Novice Teen Driver Behavior at Left-Turn Intersections.

    PubMed

    McDonald, Catherine C; Kandadai, Venk; Loeb, Helen; Seacrist, Thomas; Lee, Yi-Ching; Bonfiglio, Dana; Fisher, Donald L; Winston, Flaura K

    Collisions at left turn intersections are among the most prevalent types of teen driver serious crashes, with inadequate surveillance as a key factor. Risk awareness perception training (RAPT) has shown effectiveness in improving hazard anticipation for latent hazards. The goal of this study was to determine if RAPT version 3 (RAPT-3) improved intersection turning behaviors among novice teen drivers when the hazards were not latent and frequent glancing to multiple locations at the intersection was needed. Teens aged 16-18 with ≤180 days of licensure were randomly assigned to: 1) an intervention group (n=18) that received RAPT-3 (Trained); or 2) a control group (n=19) that received no training (Untrained). Both groups completed RAPT-3 Baseline Assessment and the Trained group completed RAPT-3 Training and RAPT-3 Post Assessment. Training effects were evaluated on a driving simulator. Simulator ( gap selection errors and collisions ) and eye tracker ( traffic check errors) metrics from six left-turn stop sign controlled intersections in the Simulated Driving Assessment (SDA) were analyzed. The Trained group scored significantly higher in RAPT-3 Post Assessment than RAPT-3 Baseline Assessment (p< 0.0001). There were no significant differences in either traffic check and gap selection errors or collisions among Trained and Untrained teens in the SDA. Though Trained teens learned about hazard anticipation related to latent hazards, learning did not translate to performance differences in left-turn stop sign controlled intersections where the hazards were not latent. Our findings point to further research to better understand the challenges teens have with left turn intersections.

  5. Effects of Cognitive Load on Driving Performance: The Cognitive Control Hypothesis.

    PubMed

    Engström, Johan; Markkula, Gustav; Victor, Trent; Merat, Natasha

    2017-08-01

    The objective of this paper was to outline an explanatory framework for understanding effects of cognitive load on driving performance and to review the existing experimental literature in the light of this framework. Although there is general consensus that taking the eyes off the forward roadway significantly impairs most aspects of driving, the effects of primarily cognitively loading tasks on driving performance are not well understood. Based on existing models of driver attention, an explanatory framework was outlined. This framework can be summarized in terms of the cognitive control hypothesis: Cognitive load selectively impairs driving subtasks that rely on cognitive control but leaves automatic performance unaffected. An extensive literature review was conducted wherein existing results were reinterpreted based on the proposed framework. It was demonstrated that the general pattern of experimental results reported in the literature aligns well with the cognitive control hypothesis and that several apparent discrepancies between studies can be reconciled based on the proposed framework. More specifically, performance on nonpracticed or inherently variable tasks, relying on cognitive control, is consistently impaired by cognitive load, whereas the performance on automatized (well-practiced and consistently mapped) tasks is unaffected and sometimes even improved. Effects of cognitive load on driving are strongly selective and task dependent. The present results have important implications for the generalization of results obtained from experimental studies to real-world driving. The proposed framework can also serve to guide future research on the potential causal role of cognitive load in real-world crashes.

  6. Distraction and task engagement: How interesting and boring information impact driving performance and subjective and physiological responses.

    PubMed

    Horrey, William J; Lesch, Mary F; Garabet, Angela; Simmons, Lucinda; Maikala, Rammohan

    2017-01-01

    As more devices and services are integrated into vehicles, drivers face new opportunities to perform additional tasks while driving. While many studies have explored the detrimental effects of varying task demands on driving performance, there has been little attention devoted to tasks that vary in terms of personal interest or investment-a quality we liken to the concept of task engagement. The purpose of this study was to explore the impact of task engagement on driving performance, subjective appraisals of performance and workload, and various physiological measurements. In this study, 31 participants (M = 37 yrs) completed three driving conditions in a driving simulator: listening to boring auditory material; listening to interesting material; and driving with no auditory material. Drivers were simultaneously monitored using near-infrared spectroscopy, heart monitoring and eye tracking systems. Drivers exhibited less variability in lane keeping and headway maintenance for both auditory conditions; however, response times to critical braking events were longer in the interesting audio condition. Drivers also perceived the interesting material to be less demanding and less complex, although the material was objectively matched for difficulty. Drivers showed a reduced concentration of cerebral oxygenated hemoglobin when listening to interesting material, compared to baseline and boring conditions, yet they exhibited superior recognition for this material. The practical implications, from a safety standpoint, are discussed. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. In the eye of the beholder: A simulator study of the impact of Google Glass on driving performance.

    PubMed

    Young, Kristie L; Stephens, Amanda N; Stephan, Karen L; Stuart, Geoffrey W

    2016-01-01

    This study examined whether, and to what extent, driving is affected by reading text on Google Glass. Reading text requires a high level of visual resources and can interfere with safe driving. However, it is currently unclear if the impact of reading text on a head-mounted display, such as Google Glass (Glass), will differ from that found with more traditional head-down electronic devices, such as a dash-mounted smartphone. A total of 20 drivers (22-48 years) completed the Lane Change Test while driving undistracted and while reading text on Glass and on a smartphone. Measures of lateral vehicle control and event detection were examined along with subjective workload and secondary task performance. Results revealed that drivers' lane keeping ability was significantly impaired by reading text on both Glass and the smartphone. When using Glass, drivers also failed to detect a greater number of lane change signs compared to when using the phone or driving undistracted. In terms of subjective workload, drivers rated reading on Glass as subjectively easier than on the smartphone, which may possibly encourage greater use of this device while driving. Overall, the results suggest that, despite Glass allowing drivers to better maintain their visual attention on the forward scene, drivers are still not able to effectively divide their cognitive attention across the Glass display and the road environment, resulting in impaired driving performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Retinal Wave Patterns Are Governed by Mutual Excitation among Starburst Amacrine Cells and Drive the Refinement and Maintenance of Visual Circuits

    PubMed Central

    Xu, Hong-Ping; Burbridge, Timothy J.; Ye, Meijun; Chen, Minggang; Ge, Xinxin; Zhou, Z. Jimmy

    2016-01-01

    Retinal waves are correlated bursts of spontaneous activity whose spatiotemporal patterns are critical for early activity-dependent circuit elaboration and refinement in the mammalian visual system. Three separate developmental wave epochs or stages have been described, but the mechanism(s) of pattern generation of each and their distinct roles in visual circuit development remain incompletely understood. We used neuroanatomical, in vitro and in vivo electrophysiological, and optical imaging techniques in genetically manipulated mice to examine the mechanisms of wave initiation and propagation and the role of wave patterns in visual circuit development. Through deletion of β2 subunits of nicotinic acetylcholine receptors (β2-nAChRs) selectively from starburst amacrine cells (SACs), we show that mutual excitation among SACs is critical for Stage II (cholinergic) retinal wave propagation, supporting models of wave initiation and pattern generation from within a single retinal cell type. We also demonstrate that β2-nAChRs in SACs, and normal wave patterns, are necessary for eye-specific segregation. Finally, we show that Stage III (glutamatergic) retinal waves are not themselves necessary for normal eye-specific segregation, but elimination of both Stage II and Stage III retinal waves dramatically disrupts eye-specific segregation. This suggests that persistent Stage II retinal waves can adequately compensate for Stage III retinal wave loss during the development and refinement of eye-specific segregation. These experiments confirm key features of the “recurrent network” model for retinal wave propagation and clarify the roles of Stage II and Stage III retinal wave patterns in visual circuit development. SIGNIFICANCE STATEMENT Spontaneous activity drives early mammalian circuit development, but the initiation and patterning of activity vary across development and among modalities. Cholinergic “retinal waves” are initiated in starburst amacrine cells and propagate to retinal ganglion cells and higher-order visual areas, but the mechanism responsible for creating their unique and critical activity pattern is incompletely understood. We demonstrate that cholinergic wave patterns are dictated by recurrent connectivity within starburst amacrine cells, and retinal ganglion cells act as “readouts” of patterned activity. We also show that eye-specific segregation occurs normally without glutamatergic waves, but elimination of both cholinergic and glutamatergic waves completely disrupts visual circuit development. These results suggest that each retinal wave pattern during development is optimized for concurrently refining multiple visual circuits. PMID:27030771

  9. A new computerized diagnostic algorithm for quantitative evaluation of binocular misalignment in patients with strabismus

    NASA Astrophysics Data System (ADS)

    Nam, Kyoung Won; Kim, In Young; Kang, Ho Chul; Yang, Hee Kyung; Yoon, Chang Ki; Hwang, Jeong Min; Kim, Young Jae; Kim, Tae Yun; Kim, Kwang Gi

    2012-10-01

    Accurate measurement of binocular misalignment between both eyes is important for proper preoperative management, surgical planning, and postoperative evaluation of patients with strabismus. In this study, we proposed a new computerized diagnostic algorithm that can calculate the angle of binocular eye misalignment photographically by using a dedicated three-dimensional eye model mimicking the structure of the natural human eye. To evaluate the performance of the proposed algorithm, eight healthy volunteers and eight individuals with strabismus were recruited in this study, the horizontal deviation angle, vertical deviation angle, and angle of eye misalignment were calculated and the angular differences between the healthy and the strabismus groups were evaluated using the nonparametric Mann-Whitney test and the Pearson correlation test. The experimental results demonstrated a statistically significant difference between the healthy and strabismus groups (p = 0.015 < 0.05), but no statistically significant difference between the proposed method and the Krimsky test (p = 0.912 > 0.05). The measurements of the two methods were highly correlated (r = 0.969, p < 0.05). From the experimental results, we believe that the proposed diagnostic method has the potential to be a diagnostic tool that measures the physical disorder of the human eye to diagnose non-invasively the severity of strabismus.

  10. Larch arabinogalactan for dry eye protection and treatment of corneal lesions: investigations in rabbits.

    PubMed

    Burgalassi, Susi; Nicosia, Nadia; Monti, Daniela; Falcone, Giulia; Boldrini, Enrico; Chetoni, Patrizia

    2007-12-01

    The aim of the present study was to investigate the corneal protective and healing properties of arabinogalactan (AG), a natural polysaccharide present in conifers of the genus Larix (Larch). AG was tested in comparison with other two polysaccharides possessing well-established properties in the treatment of dry eye: tamarind seed polysaccharide and hyaluronic acid. The AG formulation was subjected to the following investigations: rheologic measurements; evaluation of mucoadhesive properties by rheologic interaction with mucin; ferning test; and in vivo evaluation on rabbits, including treatment of an experimental dry eye; evaluation of the preocular retention; and evaluation of healing rate of experimental corneal wound. AG dispersions showed a newtonian nonviscous behavior, eta = 1.6 mPa . s for 10% w/w solution; it possessed good mucoadhesive properties useful for retention on the eye surface. In fact, a prolonged time of residence in rabbit eyes was ascertained using fluorescein-labeled AG. Five percent (5.0%) w/w AG exerted a good protective effect against the appearance of corneal dry spots. It also reduced significantly the healing time of an experimental corneal lesion since 27 h after the first treatment. These findings suggest that AG may be a potential therapeutic product for dry eye protection and for the treatment of corneal wounds.

  11. Eye tracking a self-moved target with complex hand-target dynamics

    PubMed Central

    Landelle, Caroline; Montagnini, Anna; Madelain, Laurent

    2016-01-01

    Previous work has shown that the ability to track with the eye a moving target is substantially improved when the target is self-moved by the subject's hand compared with when being externally moved. Here, we explored a situation in which the mapping between hand movement and target motion was perturbed by simulating an elastic relationship between the hand and target. Our objective was to determine whether the predictive mechanisms driving eye-hand coordination could be updated to accommodate this complex hand-target dynamics. To fully appreciate the behavioral effects of this perturbation, we compared eye tracking performance when self-moving a target with a rigid mapping (simple) and a spring mapping as well as when the subject tracked target trajectories that he/she had previously generated when using the rigid or spring mapping. Concerning the rigid mapping, our results confirmed that smooth pursuit was more accurate when the target was self-moved than externally moved. In contrast, with the spring mapping, eye tracking had initially similar low spatial accuracy (though shorter temporal lag) in the self versus externally moved conditions. However, within ∼5 min of practice, smooth pursuit improved in the self-moved spring condition, up to a level similar to the self-moved rigid condition. Subsequently, when the mapping unexpectedly switched from spring to rigid, the eye initially followed the expected target trajectory and not the real one, thereby suggesting that subjects used an internal representation of the new hand-target dynamics. Overall, these results emphasize the stunning adaptability of smooth pursuit when self-maneuvering objects with complex dynamics. PMID:27466129

  12. Application of eye movement measuring system OBER 2 to medicine and technology

    NASA Astrophysics Data System (ADS)

    Ober, Jozef; Hajda, Janusz; Loska, Jacek; Jamicki, Michal

    1997-08-01

    The OBER 2 is an infrared light eye movement measuring system and it works with IBM PC compatible computers. As one of the safest systems for measuring of eye movement it uses a very short period of infrared light flashing time (80 microsecond for each measure point). System has an advanced analog-digital controller, which includes background suppression and prediction mechanisms guaranteeing elimination of slow changes and fluctuations of external illumination frequency up to 100 Hz, with effectiveness better than 40 dB. Setting from PC the active measure axis, sampling rate (25 - 4000 Hz) and making start and stop the measure, make it possible to control the outside environment in real-time. By proper controlling of gain it is possible to get high time and position resolution of 0.5 minute of arc even for big amplitude of eye movement (plus or minus 20 degree of visual angle). The whole communication system can also be driven directly by eye movement in real time. The possibility of automatic selection of the most essential elements of eye movement, individual for each person and those that take place for each person in determined situations of life independently from personal features, is a key to practical application. Hence one of conducted research topic is a personal identification based on personal features. Another task is a research project of falling asleep detection, which can be applied to warn the drivers before falling asleep while driving. This measuring system with a proper expert system can also be used to detect a dyslexia and other disabilities of the optic system.

  13. Effect of Autologous Serum Eye Drops in Patients with Sjögren Syndrome-related Dry Eye: Clinical and In Vivo Confocal Microscopy Evaluation of the Ocular Surface.

    PubMed

    Semeraro, Francesco; Forbice, Eliana; Nascimbeni, Giuseppe; Taglietti, Marco; Romano, Vito; Guerra, Germano; Costagliola, Ciro

    To evaluate in vivo changes after therapy using autologous serum (AS) eye drops in Sjögren's syndrome (SS)-related dry eyes by confocal microscopy. In this study, 24 patients with SS-related dry eyes [12 in AS eye drop therapy and 12 in artificial tear (AT) therapy] and 24 healthy volunteers were recruited. Ocular Surface Disease Index (OSDI), central corneal thickness, tear film, break-up time, corneal and conjunctival staining, Schirmer's test and corneal confocal microscopy were investigated. Tear production, tear stability, corneal staining, inflammation, and central corneal thickness, Langherans cells, activated keratocytes, intermediate epithelial cell density, nerve tortuosity, number of sub-basal nerve branches, and number of bead-like formations differed between patients and controls (p<0.0001). The AT and AS groups differed in the OSDI, number of branches, and number of beadings (p<0.0001). AS eye drops improve symptoms and confocal microscopy findings in SS-related dry eyes. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  14. Live Speech Driven Head-and-Eye Motion Generators.

    PubMed

    Le, Binh H; Ma, Xiaohan; Deng, Zhigang

    2012-11-01

    This paper describes a fully automated framework to generate realistic head motion, eye gaze, and eyelid motion simultaneously based on live (or recorded) speech input. Its central idea is to learn separate yet interrelated statistical models for each component (head motion, gaze, or eyelid motion) from a prerecorded facial motion data set: 1) Gaussian Mixture Models and gradient descent optimization algorithm are employed to generate head motion from speech features; 2) Nonlinear Dynamic Canonical Correlation Analysis model is used to synthesize eye gaze from head motion and speech features, and 3) nonnegative linear regression is used to model voluntary eye lid motion and log-normal distribution is used to describe involuntary eye blinks. Several user studies are conducted to evaluate the effectiveness of the proposed speech-driven head and eye motion generator using the well-established paired comparison methodology. Our evaluation results clearly show that this approach can significantly outperform the state-of-the-art head and eye motion generation algorithms. In addition, a novel mocap+video hybrid data acquisition technique is introduced to record high-fidelity head movement, eye gaze, and eyelid motion simultaneously.

  15. 38 CFR 4.79 - Schedule of ratings-eye.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... retina. 6009Unhealed eye injury. General Rating Formula for Diagnostic Codes 6000 through 6009 Evaluate... irregularities, if this would result in a higher evaluation. 6012Angle-closure glaucoma: Evaluate on the basis of either visual impairment due to angle-closure glaucoma or incapacitating episodes, whichever results in a...

  16. 38 CFR 4.79 - Schedule of ratings-eye.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... retina. 6009Unhealed eye injury. General Rating Formula for Diagnostic Codes 6000 through 6009 Evaluate... irregularities, if this would result in a higher evaluation. 6012Angle-closure glaucoma: Evaluate on the basis of either visual impairment due to angle-closure glaucoma or incapacitating episodes, whichever results in a...

  17. 38 CFR 4.79 - Schedule of ratings-eye.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... retina. 6009Unhealed eye injury. General Rating Formula for Diagnostic Codes 6000 through 6009 Evaluate... irregularities, if this would result in a higher evaluation. 6012Angle-closure glaucoma: Evaluate on the basis of either visual impairment due to angle-closure glaucoma or incapacitating episodes, whichever results in a...

  18. An epidemiological survey on road traffic crashes in Iran: application of the two logistic regression models.

    PubMed

    Bakhtiyari, Mahmood; Mehmandar, Mohammad Reza; Mirbagheri, Babak; Hariri, Gholam Reza; Delpisheh, Ali; Soori, Hamid

    2014-01-01

    Risk factors of human-related traffic crashes are the most important and preventable challenges for community health due to their noteworthy burden in developing countries in particular. The present study aims to investigate the role of human risk factors of road traffic crashes in Iran. Through a cross-sectional study using the COM 114 data collection forms, the police records of almost 600,000 crashes occurred in 2010 are investigated. The binary logistic regression and proportional odds regression models are used. The odds ratio for each risk factor is calculated. These models are adjusted for known confounding factors including age, sex and driving time. The traffic crash reports of 537,688 men (90.8%) and 54,480 women (9.2%) are analysed. The mean age is 34.1 ± 14 years. Not maintaining eyes on the road (53.7%) and losing control of the vehicle (21.4%) are the main causes of drivers' deaths in traffic crashes within cities. Not maintaining eyes on the road is also the most frequent human risk factor for road traffic crashes out of cities. Sudden lane excursion (OR = 9.9, 95% CI: 8.2-11.9) and seat belt non-compliance (OR = 8.7, CI: 6.7-10.1), exceeding authorised speed (OR = 17.9, CI: 12.7-25.1) and exceeding safe speed (OR = 9.7, CI: 7.2-13.2) are the most significant human risk factors for traffic crashes in Iran. The high mortality rate of 39 people for every 100,000 population emphasises on the importance of traffic crashes in Iran. Considering the important role of human risk factors in traffic crashes, struggling efforts are required to control dangerous driving behaviours such as exceeding speed, illegal overtaking and not maintaining eyes on the road.

  19. Assessing the brain through the eye: New ways to explore hepatic encephalopathy.

    PubMed

    Arias, Natalia; Méndez, Marta; Alcalde, Ignacio; Íñigo-Portugués, Almudena; Merayo-Lloves, Jesús; Arias, Jaime; Arias, Jorge L

    2017-05-01

    Minimal hepatic encephalopathy (mHE) has been shown to affect daily functioning, quality of life, driving and overall mortality. However, little is known about treating or diagnosing early impairments in mHE. We studied one of its precipitating factors, portal hypertension which is driving the inflammatory process behind mHE. The purpose was to describe an indirect diagnostic method able to detect the pathology at early stages based on the study of the vascularization and mast cells conjunctival hyperplasia as secondary inflammatory response associated to portal hypertension. Finally, we correlated the presence of histological changes in the eye in mHE with deficits in behavioral task acquisition. Rats were trained on a stimulus-response task and a spatial working memory task using the Morris water maze. Two groups of animals were used: a SHAM (sham-operated) group (n=10) and a portal hypertension (HT) group (n=10). The triple portal vein ligation method was used to create an animal model of mHE. Latencies to reach the platform, number of glial fibrillary acidic protein-immunoreactive astrocytes (GFAP-IR), mast cell expression and presence/absence of blood and lymphatic vessels were examined. There were differences in stimulus-response behavioral performance, with a deficit in the acquisition in the HT group. However, no differences between groups were found on the spatial working memory task. At the same time, differences between groups were found in the GFAP-IR density, which was lower in the HT group, and in the number of mast cells and the presence of vessels, which were higher in the HT group. In this study, we provide the first preliminary insight into the validity of exploring the eye as a possible tool to assess the diagnosis of mHE conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Evaluation of Eye Metrics as a Detector of Fatigue

    DTIC Science & Technology

    2010-03-01

    eyeglass frames . The cameras are angled upward toward the eyes and extract real-time pupil diameter, eye-lid movement, and eye-ball movement. The...because the cameras were mounted on eyeglass -like frames , the system was able to continuously monitor the eye throughout all sessions. Overall, the...of “ fitness for duty” testing and “real-time monitoring” of operator performance has been slow (Institute of Medicine, 2004). Oculometric-based

  1. Specialized moisture retention eyewear for evaporative dry eye.

    PubMed

    Waduthantri, Samanthila; Tan, Chien Hua; Fong, Yee Wei; Tong, Louis

    2015-05-01

    To evaluate the suitablity of commercially available moisture retention eyewear for treating evaporative dry eye. Eleven patients with evaporative dry eyes were prescibed moisture retention eyewear for 3 months in addition to regular lubricant eye drops. Frequency and severity of dry eye symptoms, corneal fluorescein staining and tear break up time (TBUT) were evaluated at baseline and 3-month post-treatment. Main outcome measure was global symptom score (based on severity and frequency of dry eye symptoms on a visual analog scale) and secondary outcomes were changes in sectoral corneal fluorescein staining and tear break up time (TBUT) from pre-treatment level. There was a significant improvement in dry eye symptoms after using moisture retention eyewear for 3 months (p < 0.05). Corneal fluorescein staining in all five zones of the cornea in both eyes improved significantly (p < 0.05). There was no significant improvement in TBUT. Patients used ocular lubricants less frequently (p < 0.05) compared to the commencement of the study. Patients found moisture retention eyewear to be useful in relieving dry eye symptoms in windy, air-conditioned environments or when doing vision-related daily tasks. This study shows that moisture retention eyewear might be a valuable adjunct in management of evaporative dry eye and this new design of commercially available eyewear could have a good acceptability rate.

  2. Designing feedback to mitigate teen distracted driving: A social norms approach.

    PubMed

    Merrikhpour, Maryam; Donmez, Birsen

    2017-07-01

    The purpose of this research is to investigate teens' perceived social norms and whether providing normative information can reduce distracted driving behaviors among them. Parents are among the most important social referents for teens; they have significant influences on teens' driving behaviors, including distracted driving which significantly contributes to teens' crash risks. Social norms interventions have been successfully applied in various domains including driving; however, this approach is yet to be explored for mitigating driver distraction among teens. Forty teens completed a driving simulator experiment while performing a self-paced visual-manual secondary task in four between-subject conditions: a) social norms feedback that provided a report at the end of each drive on teens' distracted driving behavior, comparing their distraction engagement to their parent's, b) post-drive feedback that provided just the report on teens' distracted driving behavior without information on their parents, c) real-time feedback in the form of auditory warnings based on eyes of road-time, and d) no feedback as control. Questionnaires were administered to collect data on these teens' and their parents' self-reported engagement in driver distractions and the associated social norms. Social norms and real-time feedback conditions resulted in significantly smaller average off-road glance duration, rate of long (>2s) off-road glances, and standard deviation of lane position compared to no feedback. Further, social norms feedback decreased brake response time and percentage of time not looking at the road compared to no feedback. No major effect was observed for post-drive feedback. Questionnaire results suggest that teens appeared to overestimate parental norms, but no effect of feedback was found on their perceptions. Feedback systems that leverage social norms can help mitigate driver distraction among teens. Overall, both social norms and real-time feedback induced positive driving behaviors, with social norms feedback outperforming real-time feedback. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Fetal Eye Movements on Magnetic Resonance Imaging

    PubMed Central

    Woitek, Ramona; Kasprian, Gregor; Lindner, Christian; Stuhr, Fritz; Weber, Michael; Schöpf, Veronika; Brugger, Peter C.; Asenbaum, Ulrika; Furtner, Julia; Bettelheim, Dieter; Seidl, Rainer; Prayer, Daniela

    2013-01-01

    Objectives Eye movements are the physical expression of upper fetal brainstem function. Our aim was to identify and differentiate specific types of fetal eye movement patterns using dynamic MRI sequences. Their occurrence as well as the presence of conjugated eyeball motion and consistently parallel eyeball position was systematically analyzed. Methods Dynamic SSFP sequences were acquired in 72 singleton fetuses (17–40 GW, three age groups [17–23 GW, 24–32 GW, 33–40 GW]). Fetal eye movements were evaluated according to a modified classification originally published by Birnholz (1981): Type 0: no eye movements; Type I: single transient deviations; Type Ia: fast deviation, slower reposition; Type Ib: fast deviation, fast reposition; Type II: single prolonged eye movements; Type III: complex sequences; and Type IV: nystagmoid. Results In 95.8% of fetuses, the evaluation of eye movements was possible using MRI, with a mean acquisition time of 70 seconds. Due to head motion, 4.2% of the fetuses and 20.1% of all dynamic SSFP sequences were excluded. Eye movements were observed in 45 fetuses (65.2%). Significant differences between the age groups were found for Type I (p = 0.03), Type Ia (p = 0.031), and Type IV eye movements (p = 0.033). Consistently parallel bulbs were found in 27.3–45%. Conclusions In human fetuses, different eye movement patterns can be identified and described by MRI in utero. In addition to the originally classified eye movement patterns, a novel subtype has been observed, which apparently characterizes an important step in fetal brainstem development. We evaluated, for the first time, eyeball position in fetuses. Ultimately, the assessment of fetal eye movements by MRI yields the potential to identify early signs of brainstem dysfunction, as encountered in brain malformations such as Chiari II or molar tooth malformations. PMID:24194885

  4. The effect of topical apraclonidine on subconjunctival hemorrhage and flap adherence in LASIK patients.

    PubMed

    Aslanides, loannis M; Tsiklis, Nikolaos S; Ozkilic, Efekan; Coskunseven, Efekan; Pallikaris, loannis G; Jankov, Mirko R

    2006-06-01

    To determine whether the use of topical apraclonidine just before the LASIK procedure prevents subconjunctival hemorrhage and to study its effect on postoperative flap adherence. Topical apraclonidine 0.125% was randomly applied to 1 eye of 66 myopic patients who underwent primary bilateral LASIK. Apraclonidine was instilled 1 hour prior to and 30 seconds before placing the vacuum ring of the microkeratome, whereas the other eye served as control. Thirty minutes after the operation, all patients were examined by the surgeon to evaluate hyperemia and identify flap-related complications (eg, slippage, dislocation, or flap folds). The size of subconjunctival hemorrhage was also evaluated on postoperative days 1 and 7. All 132 eyes in the study were examined after surgery to identify flap folds and/or their dislocation. In the apraclonidine group, 48 (72.8%) eyes had no hyperemia, 16 (24.2%) eyes had mild hyperemia, 2 (3%) eyes had moderate hyperemia, and no (0%) eyes had severe hyperemia. In the control group, 37 (56.1%) eyes had mild hyperemia, 21 (31.8%) eyes had moderate hyperemia, 1 (1.5%) eye had severe hyperemia, and 7 (10.6%) eyes had no hyperemia. In the apraclonidine group, 44 (66.7%) eyes had no subconjunctival hemorrhage (grade 0); grade 1 was present in 19 (28.8%) eyes whereas grades 2 and 3 were present in 2 (3%) eyes and 1 (1.5%) eye, respectively. In the control group, 19 (28.8%) eyes showed grade 0, 13 (19.7%) eyes had grade 1, and grades 2 and 3 were present in 20 (30.3%) eyes and 14 (21.2%) eyes, respectively. Chi-square test showed a highly significant difference between the two groups (P < .001). No flap-related problems were reported in either group. Topical apraclonidine applied before LASIK surgery may prevent immediate postoperative hyperemia and prolonged subconjunctival hemorrhage by its alpha-mimetic vasoconstrictor effect without inducing flap adherence complication.

  5. Posterior Vitreous Detachment With Microplasmin Alters the Retinal Penetration of Intravitreal Bevacizumab (Avastin) in Rabbit Eyes

    PubMed Central

    Goldenberg, David T.; Giblin, Frank J.; Cheng, Mei; Chintala, Shravan K.; Trese, Michael T.; Drenser, Kimberly A.; Ruby, Alan J.

    2010-01-01

    Purpose Intravitreal bevacizumab (Avastin) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare bevacizumab (BV) retinal penetration in rabbit eyes with and without a MP-induced PVD. Methods Twelve adult rabbits were injected with 0.1 ml (0.4 mg) of MP into the vitreous cavity of one eye. One week later, the rabbits were injected with 0.05 ml (1.25 mg) of BV into both eyes. Both eyes of three rabbits each were harvested at 6, 12, 24, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intra-retinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 ml of MP in one eye. One week later, both eyes from each rabbit were enucleated and frozen retinal sections were prepared and analyzed with light microscopy to evaluate for histologic damage. Results Full thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All of the MP-injected eyes exhibited increased antibody labeling in retinas evaluated 6, 12, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By three days after BV injection, all eyes demonstrated decreased antibody labeling compared to earlier time periods. At three days, one rabbit showed increased antibody labeling in the retina of the non-MP-injected eye compared with the contralateral MP-injected eye, and two rabbits exhibited similar antibody labeling in both eyes. When compared with control eyes, light microscopy demonstrated normal retinal histologic findings in eyes injected only with microplasmin. Conclusions Increased BV retinal penetration is observed initially in eyes with a MP-induced PVD, and the mechanism is likely multifactorial. By three days, retinal penetration is similar in eyes with and without a PVD. Although it is difficult to directly extrapolate to humans, our study suggests a PVD may alter the retinal penetration of BV. PMID:21099453

  6. Forging Ahead (linearized)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This animation shows the front view from the Mars Exploration Rover Opportunity as it drives north towards the eastern edge of the rock outcropping near its landing site at Meridiani Planum, Mars. The movie strings together images taken over the past six martian days, or sols, of its journey, beginning with a 1 meter (3 feet) stroll away from the lander on sol 7. On the 12th sol, Opportunity drove another 3 1/2 meters (11 feet), and then, one sol later, another 1 1/2 meters (5 feet). On its way, the rover twisted and turned in a test of its driving capabilities. This movie is made up of images taken by the rover's front hazard-identification camera, which were corrected for fish-eye distortion.

  7. Visual and anatomic outcomes of golf ball-related ocular injuries.

    PubMed

    Park, S J; Park, K H; Heo, J W; Woo, S J

    2014-03-01

    To investigate the characteristics and prognoses of golf ball-related ocular injuries (GROIs) using standardized terminology, classification, and scoring systems. Twenty-two GROI patients were assessed using the Birmingham Eye Trauma Terminology, Ocular Trauma Classification Group (OTCG) classification, and Ocular Trauma Score. Globe preservation and final visual acuity (FVA) were assessed according to the injury severity categorical designation. Fourteen patients were injured on golf courses and eight on driving ranges. Nine patients (40.9%) had open-globe injuries (five ruptures (22.7%), four penetrating injuries (18.2%)). All rupture cases required enucleation, whereas penetrating injury cases did not (the FVA ranged from 20/100 to no light perception). In open-globe injuries, wearing glasses protected against rupture (P=0.008). Thirteen patients sustained closed-globe injuries that were accompanied by lens subluxation (38.5%), choroidal rupture (30.8%), macular commotio retinae (38.5%), and traumatic optic neuropathy (7.7%). Twelve (54.5%) patients had orbital wall fractures. The mean number of related surgeries required was 1.5±1.7 across all patients. Eyes with GROIs had devastating FVA and globe preservation status, especially those with open-globe injuries. Observing golf rules and improving driving-range facilities are essential for preventing GROIs. Protective eyewear may reduce ocular damage from GROIs, especially globe rupture.

  8. Visual and anatomic outcomes of golf ball-related ocular injuries

    PubMed Central

    Park, S J; Park, K H; Heo, J W; Woo, S J

    2014-01-01

    Aims To investigate the characteristics and prognoses of golf ball-related ocular injuries (GROIs) using standardized terminology, classification, and scoring systems. Methods Twenty-two GROI patients were assessed using the Birmingham Eye Trauma Terminology, Ocular Trauma Classification Group (OTCG) classification, and Ocular Trauma Score. Globe preservation and final visual acuity (FVA) were assessed according to the injury severity categorical designation. Results Fourteen patients were injured on golf courses and eight on driving ranges. Nine patients (40.9%) had open-globe injuries (five ruptures (22.7%), four penetrating injuries (18.2%)). All rupture cases required enucleation, whereas penetrating injury cases did not (the FVA ranged from 20/100 to no light perception). In open-globe injuries, wearing glasses protected against rupture (P=0.008). Thirteen patients sustained closed-globe injuries that were accompanied by lens subluxation (38.5%), choroidal rupture (30.8%), macular commotio retinae (38.5%), and traumatic optic neuropathy (7.7%). Twelve (54.5%) patients had orbital wall fractures. The mean number of related surgeries required was 1.5±1.7 across all patients. Conclusion Eyes with GROIs had devastating FVA and globe preservation status, especially those with open-globe injuries. Observing golf rules and improving driving-range facilities are essential for preventing GROIs. Protective eyewear may reduce ocular damage from GROIs, especially globe rupture. PMID:24384962

  9. Commentary driver training: Effects of commentary exposure, practice and production on hazard perception and eye movements.

    PubMed

    Young, Angela H; Crundall, David; Chapman, Peter

    2017-04-01

    Commentary driving typically involves being trained in how to produce a verbal running commentary about what you can see, what you are doing, what might happen and what action you will take to avoid potential hazards, while driving. Although video-based commentary training has been associated with subsequent hazard perception improvements, it can have a negative impact on hazard perception when a live commentary is produced at test (Young, Chapman, & Crundall, 2014). In the current study we use balanced training and testing blocks to isolate the effects of commentary exposure, production of a commentary with and without practice, and learning from earlier self-generation of commentary on behavioural and eye movement measures. Importantly, both commentary exposed and unexposed groups gave hazard perception responses during the commentary video, ensuring that the unexposed control group remained engaged in the procedure throughout. Results show that producing a live commentary is detrimental to concurrent hazard perception, even after practice, and does not enhance any later effect of commentary exposure. Although commentary exposure led to an initial increase in the accuracy of hazard perception responses, this effect was limited to the first occasion of testing, and showed no later benefits relative to engaged hazard exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Ultrasonography of the eye and orbit.

    PubMed

    Eisenberg, H M

    1985-11-01

    The eye and orbit are excellent subjects for ultrasonic evaluation. Examination and interpretation are relatively simple procedures. The normal ultrasonic anatomy of the eye and orbit is presented. Some examples of ocular and orbital pathology are discussed also.

  11. Difficulties of Drivers With Dyslexia When Reading Traffic Signs: Analysis of Reading, Eye Gazes, and Driving Performance.

    PubMed

    Tejero, Pilar; Insa, Beatriz; Roca, Javier

    2018-03-01

    A group of adult individuals with dyslexia and a matched group of normally reading individuals participated in a driving simulation experiment. Participants were asked to read the word presented on every direction traffic sign encountered along a route, as far as possible from the sign, maintaining driving performance. Word frequency and word length were manipulated as within-subject factors. We analyzed (a) reading accuracy, (b) how far the sign was when the participant started to give the response, (c) where the participant looked during the time leading up to the response, and (d) the variability of the vehicle's speed during that time and during driving on similar segments of the route that did not present the traffic signs. Individuals with dyslexia showed lower levels of performance in the reading task, the roles of word frequency and word length were more influential for them, and there was larger variability of the vehicle's speed during the time they were attempting to read the traffic sign, which did not occur during their driving on similar segments that did not present the targeted traffic signs. Therefore, the specific needs of individuals with dyslexia on the road should be considered in plans aimed at increasing traffic safety and fluidity.

  12. Analysis of Fundus Shape in Highly Myopic Eyes by Using Curvature Maps Constructed from Optical Coherence Tomography

    PubMed Central

    Miyake, Masahiro; Yamashiro, Kenji; Akagi-Kurashige, Yumiko; Oishi, Akio; Tsujikawa, Akitaka; Hangai, Masanori; Yoshimura, Nagahisa

    2014-01-01

    Purpose To evaluate fundus shape in highly myopic eyes using color maps created through optical coherence tomography (OCT) image analysis. Methods We retrospectively evaluated 182 highly myopic eyes from 113 patients. After obtaining 12 lines of 9-mm radial OCT scans with the fovea at the center, the Bruch’s membrane line was plotted and its curvature was measured at 1-µm intervals in each image, which was reflected as a color topography map. For the quantitative analysis of the eye shape, mean absolute curvature and variance of curvature were calculated. Results The color maps allowed staphyloma visualization as a ring of green color at the edge and as that of orange-red color at the bottom. Analyses of mean and variance of curvature revealed that eyes with myopic choroidal neovascularization tended to have relatively flat posterior poles with smooth surfaces, while eyes with chorioretinal atrophy exhibited a steep, curved shape with an undulated surface (P<0.001). Furthermore, eyes with staphylomas and those without clearly differed in terms of mean curvature and the variance of curvature: 98.4% of eyes with staphylomas had mean curvature ≥7.8×10−5 [1/µm] and variance of curvature ≥0.26×10−8 [1/µm]. Conclusions We established a novel method to analyze posterior pole shape by using OCT images to construct curvature maps. Our quantitative analysis revealed that fundus shape is associated with myopic complications. These values were also effective in distinguishing eyes with staphylomas from those without. This tool for the quantitative evaluation of eye shape should facilitate future research of myopic complications. PMID:25259853

  13. Investigation of the morphology of the features generated via femtosecond lasers in the interior of a bovine cornea sections

    NASA Astrophysics Data System (ADS)

    Vukelic, Sinisa; Kongsuwan, Panjawat; Yao, Y. Lawrence

    2013-02-01

    Nonlinear absorption of femtosecond laser pulses enables the induction of bubble cavities in the interior of eye cornea without affecting other parts of an eye, a phenomena utilized for flap formation in laser assisted corneal surgery. In the present study laser pulses were focused in the interior of the sections of bovine cornea. Tight focus of the laser pulses results in the plasma formation followed by its explosive expansion, which drives cavity formation. The morphology of the generated features as well as the nature of the physical mechanisms of the phenomenon as a function of process parameters is discussed. Numerical model is proposed to develop predictive capabilities for the feature size and shape and the results are compared against the experimental findings.

  14. Temperature profiles of patient-applied eyelid warming therapies.

    PubMed

    Wang, Michael T M; Gokul, Akilesh; Craig, Jennifer P

    2015-12-01

    To compare temperature profile characteristics (on and off eye) of two patient-applied heat therapies for meibomian gland dysfunction (MGD): an eye mask containing disposable warming units (EyeGiene(®)) and a microwave-heated flaxseed eye bag(®) (MGDRx EyeBag(®)). In vitro evaluation: surface temperature profiles of activated eye masks and heated eye bags(®) (both n=10), were tracked every 10s until return to ambient temperature. Heat-transfer assessment: outer and inner eyelid temperature profiles throughout the eye mask and eye bag(®) treatment application period (10min) were investigated in triplicate. The devices were applied for 12 different time intervals in a randomised order, with a cool-down period in between to ensure ocular temperatures returned to baseline. Temperature measurements were taken before and immediately after each application. In vitro evaluation: on profile, the eye bag(®) surface temperature peaked earlier (0±0 s vs. 100±20 s, p<0.001), cooled more slowly and displayed less variability than the eye mask (all p<0.05). Heat-transfer assessment: the eye bag(®) effected higher peak inner eyelid temperatures (38.1±0.4°C vs. 37.4±0.2°C, p=0.04), as well as larger inner eyelid temperature increases over the first 2 min, and between 9 and 10 min (all p<0.05). The eye bag(®) surface temperature profile displayed greater uniformity and slower cooling than the eye mask, and was demonstrated to be significantly more effective in raising ocular temperatures than the eye mask, both statistically and clinically. This has implications for MGD treatment, where the melting points of meibomian secretions are likely to be higher with increasing disease severity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Eye wash water flow direction study: an evaluation of the effectiveness of eye wash devices with opposite directional water flow.

    PubMed

    Fogt, Jennifer S; Jones-Jordan, Lisa A; Barr, Joseph T

    2018-01-01

    New designs of eye wash stations have been developed in which the direction of water flow from the fountain has been reversed, with two water streams originating nasally in both eyes and flowing toward the temporal side of each eye. No study has been done to determine the ideal direction of water flow coming from the eye wash in relation to the eye. Ophthalmic eye examinations were conducted before and after the use of two eye wash stations with opposite water flow directionality. Fluorescein was instilled in both eyes before using an eye wash to measure the effectiveness of the water flow. Subjects were surveyed upon their experiences using the eye washes. Ophthalmic examination found no significant difference in the efficacy of the eye washes with nasal-to-temporal water flow when compared to temporal-to-nasal water flow direction.

  16. fMRI evidence for sensorimotor transformations in human cortex during smooth pursuit eye movements.

    PubMed

    Kimmig, H; Ohlendorf, S; Speck, O; Sprenger, A; Rutschmann, R M; Haller, S; Greenlee, M W

    2008-01-01

    Smooth pursuit eye movements (SP) are driven by moving objects. The pursuit system processes the visual input signals and transforms this information into an oculomotor output signal. Despite the object's movement on the retina and the eyes' movement in the head, we are able to locate the object in space implying coordinate transformations from retinal to head and space coordinates. To test for the visual and oculomotor components of SP and the possible transformation sites, we investigated three experimental conditions: (I) fixation of a stationary target with a second target moving across the retina (visual), (II) pursuit of the moving target with the second target moving in phase (oculomotor), (III) pursuit of the moving target with the second target remaining stationary (visuo-oculomotor). Precise eye movement data were simultaneously measured with the fMRI data. Visual components of activation during SP were located in the motion-sensitive, temporo-parieto-occipital region MT+ and the right posterior parietal cortex (PPC). Motor components comprised more widespread activation in these regions and additional activations in the frontal and supplementary eye fields (FEF, SEF), the cingulate gyrus and precuneus. The combined visuo-oculomotor stimulus revealed additional activation in the putamen. Possible transformation sites were found in MT+ and PPC. The MT+ activation evoked by the motion of a single visual dot was very localized, while the activation of the same single dot motion driving the eye was rather extended across MT+. The eye movement information appeared to be dispersed across the visual map of MT+. This could be interpreted as a transfer of the one-dimensional eye movement information into the two-dimensional visual map. Potentially, the dispersed information could be used to remap MT+ to space coordinates rather than retinal coordinates and to provide the basis for a motor output control. A similar interpretation holds for our results in the PPC region.

  17. Effect of glaucoma on eye movement patterns and laboratory-based hazard detection ability

    PubMed Central

    Black, Alex A.; Wood, Joanne M.

    2017-01-01

    Purpose The mechanisms underlying the elevated crash rates of older drivers with glaucoma are poorly understood. A key driving skill is timely detection of hazards; however, the hazard detection ability of drivers with glaucoma has been largely unexplored. This study assessed the eye movement patterns and visual predictors of performance on a laboratory-based hazard detection task in older drivers with glaucoma. Methods Participants included 30 older drivers with glaucoma (71±7 years; average better-eye mean deviation (MD) = −3.1±3.2 dB; average worse-eye MD = −11.9±6.2 dB) and 25 age-matched controls (72±7 years). Visual acuity, contrast sensitivity, visual fields, useful field of view (UFoV; processing speeds), and motion sensitivity were assessed. Participants completed a computerised Hazard Perception Test (HPT) while their eye movements were recorded using a desk-mounted Tobii TX300 eye-tracking system. The HPT comprises a series of real-world traffic videos recorded from the driver’s perspective; participants responded to road hazards appearing in the videos, and hazard response times were determined. Results Participants with glaucoma exhibited an average of 0.42 seconds delay in hazard response time (p = 0.001), smaller saccades (p = 0.010), and delayed first fixation on hazards (p<0.001) compared to controls. Importantly, larger saccades were associated with faster hazard responses in the glaucoma group (p = 0.004), but not in the control group (p = 0.19). Across both groups, significant visual predictors of hazard response times included motion sensitivity, UFoV, and worse-eye MD (p<0.05). Conclusions Older drivers with glaucoma had delayed hazard response times compared to controls, with associated changes in eye movement patterns. The association between larger saccades and faster hazard response time in the glaucoma group may represent a compensatory behaviour to facilitate improved performance. PMID:28570621

  18. Quantitative Assessment of Eye Phenotypes for Functional Genetic Studies Using Drosophila melanogaster

    PubMed Central

    Iyer, Janani; Wang, Qingyu; Le, Thanh; Pizzo, Lucilla; Grönke, Sebastian; Ambegaokar, Surendra S.; Imai, Yuzuru; Srivastava, Ashutosh; Troisí, Beatriz Llamusí; Mardon, Graeme; Artero, Ruben; Jackson, George R.; Isaacs, Adrian M.; Partridge, Linda; Lu, Bingwei; Kumar, Justin P.; Girirajan, Santhosh

    2016-01-01

    About two-thirds of the vital genes in the Drosophila genome are involved in eye development, making the fly eye an excellent genetic system to study cellular function and development, neurodevelopment/degeneration, and complex diseases such as cancer and diabetes. We developed a novel computational method, implemented as Flynotyper software (http://flynotyper.sourceforge.net), to quantitatively assess the morphological defects in the Drosophila eye resulting from genetic alterations affecting basic cellular and developmental processes. Flynotyper utilizes a series of image processing operations to automatically detect the fly eye and the individual ommatidium, and calculates a phenotypic score as a measure of the disorderliness of ommatidial arrangement in the fly eye. As a proof of principle, we tested our method by analyzing the defects due to eye-specific knockdown of Drosophila orthologs of 12 neurodevelopmental genes to accurately document differential sensitivities of these genes to dosage alteration. We also evaluated eye images from six independent studies assessing the effect of overexpression of repeats, candidates from peptide library screens, and modifiers of neurotoxicity and developmental processes on eye morphology, and show strong concordance with the original assessment. We further demonstrate the utility of this method by analyzing 16 modifiers of sine oculis obtained from two genome-wide deficiency screens of Drosophila and accurately quantifying the effect of its enhancers and suppressors during eye development. Our method will complement existing assays for eye phenotypes, and increase the accuracy of studies that use fly eyes for functional evaluation of genes and genetic interactions. PMID:26994292

  19. The Rat With Oxygen-Induced Retinopathy Is Myopic With Low Retinal Dopamine

    PubMed Central

    Zhang, Nan; Favazza, Tara L.; Baglieri, Anna Maria; Benador, Ilan Y.; Noonan, Emily R.; Fulton, Anne B.; Hansen, Ronald M.; Iuvone, P. Michael; Akula, James D.

    2013-01-01

    Purpose. Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. Methods. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). Results. The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. Conclusions. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia. PMID:24168993

  20. The rat with oxygen-induced retinopathy is myopic with low retinal dopamine.

    PubMed

    Zhang, Nan; Favazza, Tara L; Baglieri, Anna Maria; Benador, Ilan Y; Noonan, Emily R; Fulton, Anne B; Hansen, Ronald M; Iuvone, P Michael; Akula, James D

    2013-12-19

    Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia.

  1. In Vivo Confocal Microscopic Evaluation of Corneal Langerhans Cells in Dry Eye Patients§

    PubMed Central

    Machetta, Federica; Fea, Antonio M; Actis, Alessandro G; de Sanctis, Ugo; Dalmasso, Paola; Grignolo, Federico M

    2014-01-01

    Purpose. To assess inflammatory involvement of cornea in dry eye by means of confocal microscopy, evaluating the presence and distribution of Langherans cells (LCs). Methods: 98 eyes of 49 subjects were enrolled: 18 subjects affected by Sjögren Syndrome Dry Eye (SSDE), 17 with Non-Sjögren Syndrome Dry Eye (NSSDE), 14 healthy volunteeers. Dry eye symptoms, tear film, ocular surface damage and corneal confocal microscopy were analized. Results: A significant increase of LCs density was observed at sub-basal nerve plexus (SSDE = 79 cells/mm2 andNDE = 22 cells/mm2; p = 0,0031) and sub-epithelial nerve plexus (SSDE = 38 cells/mm2 and NDE = 3 cells/mm2; p = 0,0169) in central cornea of SSDE group. An increased number of LCs from the center to the periphery of the cornea was observed, significant only in healthy volunteers group. In dry eye patients there was an increase in LCs density in both peripheral and central cornea with a significant difference between NDE (14,66 cells/mm2) and SSDE (56,66 cells/mm2) only in central cornea (p = 0,0028). In SSDE group, mean density of LCs in central cornea results also superior to NSSDE group (29,33 cells/mm2). There was no correlation between LCs density and dry eye symptoms, tear film deficiency and ocular surface damage. Conclusion: This study demonstrates the activation of an inflammatory and immunological reaction in cornea of NSSDE and SSDE patients. Confocal microscopy can be an important diagnostic tool in evaluation and follow-up of dry eye disease. PMID:25317216

  2. Impact of fungal species cultured on outcome in horses with fungal keratitis.

    PubMed

    Sherman, Amanda B; Clode, Alison B; Gilger, Brian C

    2017-03-01

    To determine the significance of Aspergillus and Fusarium spp., as identified by culture, on clinical outcome in equine keratomycosis. Retrospective analysis of 66 horses (66 eyes) evaluated at the NCSU-VH diagnosed with keratomycosis from which Aspergillus or Fusarium spp. were cultured. Horses were classified into those who improved with medical management alone or those who required surgical intervention to improve. Horses who underwent surgery were divided into globe-sparing procedures or enucleation. Effects of bacterial co-infection, previous topical steroid or antifungal use, and time of year on fungal genus and outcome were evaluated. Aspergillus spp. was cultured from 41 eyes (63%), while 24 eyes (37%) cultured Fusarium spp. One horse cultured both species and was not included in further evaluation. From the horses that cultured Aspergillus spp., 28 eyes (68%) required surgical intervention to control the infection: 21 (75%) of these eyes maintained globe integrity, while 7 eyes (25%) were enucleated. Of those horses with Fusarium spp., 14 eyes (58%) required surgical intervention: 11 (79%) of these eyes maintained globe integrity, while 3 eyes (21%) were enucleated. Genus of fungus cultured was not significantly associated with the need for surgical intervention nor was it significantly associated with the necessity of globe-sparing surgery versus enucleation. Additionally, bacterial co-infection, previous steroidal or antifungal use, and time of year did not affect outcome or type of fungal species cultured. Equine keratomycosis from Fusarium spp. compared to keratomycosis from Aspergillus spp. is not associated with a different clinical outcome. © 2016 American College of Veterinary Ophthalmologists.

  3. Comparison of glaucoma diagnostic accuracy of macular ganglion cell complex thickness based on nonhighly myopic and highly myopic normative database

    PubMed Central

    Chen, Henry Shen-Lih; Liu, Chun-Hsiu; Lu, Da-Wen

    2016-01-01

    Background/Purpose: To evaluate and compare the diagnostic discriminative ability for detecting glaucoma in highly myopic eyes from a normative database of macular ganglion cell complex (mGCC) thickness based on nonhighly myopic and highly myopic normal eyes. Methods: Forty-nine eyes of 49 participants with high myopia (axial length ≥ 26.0 mm) were enrolled. Spectral-domain optical coherence tomography scans were done using RS-3000, and the mGCC thickness/significance maps within a 9-mm diameter circle were generated using built-in software. We compared the difference of sensitivity, specificity, and diagnostic accuracy between the nonhighly myopic database and the highly myopic database for differentiating the early glaucomatous eyes from the nonglaucomatous eyes. Results: This study enrolled 15 normal eyes and 34 eyes with glaucoma. The mean mGCC thickness of the glaucoma group was significantly less than that of the normal group (p < 0.001). Sensitivity was 96.3%, and the specificity was 50.0% when using the nonhighly myopic normative database. When the highly myopic normative database was used, the sensitivity was 88.9%, and the specificity was 90.0%. The false positive rate was significantly lower when using the highly myopic normative database (p < 0.05). Conclusion: The evaluations of glaucoma in eyes with high myopia using a nonhighly myopic normative database may lead to a frequent misdiagnosis. When evaluating glaucoma in high myopic eyes, the mGCC thickness determined by the long axial length high myopic normative database should be applied. PMID:29018704

  4. Different cellular effects of four anti-inflammatory eye drops on human corneal epithelial cells: independent in active components.

    PubMed

    Qu, Mingli; Wang, Yao; Yang, Lingling; Zhou, Qingjun

    2011-01-01

    To evaluate and compare the cellular effects of four commercially available anti-inflammatory eye drops and their active components on human corneal epithelial cells (HCECs) in vitro. The cellular effects of four eye drops (Bromfenac Sodium Hydrate Eye Drops, Pranoprofen Eye Drops, Diclofenac Sodium Eye Drops, and Tobramycin & Dex Eye Drops) and their corresponding active components were evaluated in an HCEC line with five in vitro assays. Cell proliferation and migration were measured using 3-(4,5)-dimethylthiahiazo (-z-y1)-3 5-di-phenytetrazoliumromide (MTT) assay and transwell migration assay. Cell damage was determined with the lactate dehydrogenase (LDH) assay. Cell viability and median lethal time (LT₅₀) were measured by 7-amino-actinomycin D (7-AAD) staining and flow cytometry analysis. Cellular effects after exposure of HCECs to the four anti-inflammatory eye drops were concentration dependent. The differences of cellular toxicity on cell proliferation became significant at lower concentrations (<0.002%). Diclofenac Sodium Eye Drops showed significant increasing effects on cell damage and viability when compared with the other three solutions. Tobramycin & Dex Eye Drops inhibited the migration of HCECs significantly. Tobramycin & Dex Eye Drops showed the quickest effect on cell viability: the LT₅₀ was 3.28, 9.23, 10.38, and 23.80 min for Tobramycin & Dex Eye Drops, Diclofenac Sodium Eye Drops, Pranoprofen Eye Drops, and Bromfenac Sodium Hydrate Eye Drops, respectively. However, the comparisons of cellular toxicity revealed significant differences between the eye drops and their active components under the same concentration. The corneal epithelial toxicity differences among the active components of the four eye drops became significant as higher concentration (>0.020%). The four anti-inflammatory eye drops showed different cellular effects on HCECs, and the toxicity was not related with their active components, which provides new reference for the clinical application and drug research and development.

  5. Objective Methods to Test Visual Dysfunction in the Presence of Cognitive Impairment

    DTIC Science & Technology

    2015-12-01

    the eye and 3) purposeful eye movements to track targets that are resolved. Major Findings: Three major objective tests of vision were successfully...developed and optimized to detect disease. These were 1) the pupil light reflex (either comparing the two eyes or independently evaluating each eye ...separately for retina or optic nerve damage, 2) eye movement based analysis of target acquisition, fixation, and eccentric viewing as a means of

  6. Effect of eye rubbing on signs and symptoms of allergic conjunctivitis in cat-sensitive individuals.

    PubMed

    Raizman, M B; Rothman, J S; Maroun, F; Rand, W M

    2000-12-01

    To evaluate the effect of eye rubbing on signs and symptoms of allergic conjunctivitis in cat-sensitive individuals. Two prospective, nonrandomized comparative studies. Thirteen patients in the first study and 20 patients in the second study with a documented history of acute allergic conjunctivitis induced by exposure to cats were enrolled. In the first trial, all patients had one eye rubbed 15 times by the investigator without exposure to airborne allergens. Both eyes were evaluated after 5, 15, 30, and 60 minutes using subject questionnaires and slit-lamp examination. At least 1 week later, each patient was exposed to cat dander for 75 minutes; 15 minutes after entering the cat room, each patient had one eye rubbed 15 times by the examiner. Subjects' eyes were then evaluated using questionnaires and slit-lamp examination. In the second trial, the visits were identical to the first trial, except that the rubbed eye in each visit was rubbed 20 times and with more force, and that patients wore masks during exposure to cat dander. In both studies, the difference between patients' rubbed and nonrubbed eyes with respect to ocular itching, chemosis, and hyperemia was noted 5, 15, 30, and 60 minutes after controlled eye rubbing. Without exposure to the cat room, rubbed eyes exhibited increased itching at 5 minutes in both studies and at 15 minutes in the second study (P < 0.05), increased chemosis at 5 and 15 minutes in the second study (P < 0.05), and increased hyperemia at 5 minutes in the second study (P < 0.05) compared with nonrubbed eyes. During exposure to cat dander, rubbed eyes consistently exhibited increased itching at 5, 15, and 30 minutes in the first and second study as well as at 60 minutes in the second study compared with nonrubbed eyes. Furthermore, during exposure to cat dander, rubbed eyes consistently exhibited increased chemosis at 5 and 15 minutes (P < 0.05) and increased hyperemia at 5, 15, and 30 minutes (P < 0.05) in the second study compared with nonrubbed eyes. Firm eye rubbing causes a mild and transient increase in ocular itching, chemosis, and hyperemia. However, after exposure to cat allergens in cat-sensitive individuals, the effects of eye rubbing are longer and more dramatic. Eye rubbing may play a role in ocular signs and symptoms of allergic conjunctivitis in cat-sensitive individuals, especially after exposure to cat dander.

  7. A single LipiFlow® Thermal Pulsation System treatment improves meibomian gland function and reduces dry eye symptoms for 9 months.

    PubMed

    Greiner, Jack V

    2012-04-01

    To evaluate the effect of a single treatment with the LipiFlow(®) Thermal Pulsation System on signs of meibomian gland dysfunction (MGD) and dry eye symptoms over a 9-month period. Patients (n = 42 eyes, 21 subjects) diagnosed with MGD and dry eye symptoms were recruited for a non-significant risk, prospective, open-label, 1-month clinical trial. Patients received a single 12-minute treatment using the LipiFlow(®) Thermal Pulsation System on each eye. The LipiFlow(®) device applies heat to the conjunctival surfaces of the upper and lower inner eyelids while simultaneously applying pulsatile pressure to the outer eyelid surfaces to express the meibomian glands. Patient symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Standard Patient Evaluation for Eye Dryness (SPEED) dry eye questionnaires; tear break-up time was measured with the dry eye test (DET™); and meibomian gland function was evaluated using a standardized diagnostic expression technique. Data are presented for patient's pre-treatment (baseline) and at 1-month and 9-month post-treatment. Meibomian gland secretion scores improved significantly from baseline (4.4 ± 4.0) to 1-month post-treatment (11.3 ± 6.2; p < 0.0001) and this improvement was maintained with no significant regression at 9 months (11.7 ± 5.9). Similarly, baseline tear break-up time (4.8 ± 3.2) was significantly increased at 1 month (9.6 ± 7.6; p < 0.001) and this increase was maintained with no significant regression at 9 months (7.1 ± 5.6). Symptom scores on both OSDI and SPEED questionnaires improved significantly at 1 month (p < 0.0001) and this improvement was maintained at 9 months. With such prolonged improvement in signs and symptoms of dry eye disease, the LipiFlow(®) Thermal Pulsation System offers a technological advancement for the treatment of dry eye disease secondary to meibomian gland dysfunction. A single 12-minute LipiFlow(®) treatment results in up to 9 months of sustained improvement of meibomian gland function, tear break-up time and dry eye symptoms that are unparalleled with current dry eye treatments.

  8. Terminator Disparity Contributes to Stereo Matching for Eye Movements and Perception

    PubMed Central

    Optican, Lance M.; Cumming, Bruce G.

    2013-01-01

    In the context of motion detection, the endings (or terminators) of 1-D features can be detected as 2-D features, affecting the perceived direction of motion of the 1-D features (the barber-pole illusion) and the direction of tracking eye movements. In the realm of binocular disparity processing, an equivalent role for the disparity of terminators has not been established. Here we explore the stereo analogy of the barber-pole stimulus, applying disparity to a 1-D noise stimulus seen through an elongated, zero-disparity, aperture. We found that, in human subjects, these stimuli induce robust short-latency reflexive vergence eye movements, initially in the direction orthogonal to the 1-D features, but shortly thereafter in the direction predicted by the disparity of the terminators. In addition, these same stimuli induce vivid depth percepts, which can only be attributed to the disparity of line terminators. When the 1-D noise patterns are given opposite contrast in the two eyes (anticorrelation), both components of the vergence response reverse sign. Finally, terminators drive vergence even when the aperture is defined by a texture (as opposed to a contrast) boundary. These findings prove that terminators contribute to stereo matching, and constrain the type of neuronal mechanisms that might be responsible for the detection of terminator disparity. PMID:24285893

  9. Terminator disparity contributes to stereo matching for eye movements and perception.

    PubMed

    Quaia, Christian; Optican, Lance M; Cumming, Bruce G

    2013-11-27

    In the context of motion detection, the endings (or terminators) of 1-D features can be detected as 2-D features, affecting the perceived direction of motion of the 1-D features (the barber-pole illusion) and the direction of tracking eye movements. In the realm of binocular disparity processing, an equivalent role for the disparity of terminators has not been established. Here we explore the stereo analogy of the barber-pole stimulus, applying disparity to a 1-D noise stimulus seen through an elongated, zero-disparity, aperture. We found that, in human subjects, these stimuli induce robust short-latency reflexive vergence eye movements, initially in the direction orthogonal to the 1-D features, but shortly thereafter in the direction predicted by the disparity of the terminators. In addition, these same stimuli induce vivid depth percepts, which can only be attributed to the disparity of line terminators. When the 1-D noise patterns are given opposite contrast in the two eyes (anticorrelation), both components of the vergence response reverse sign. Finally, terminators drive vergence even when the aperture is defined by a texture (as opposed to a contrast) boundary. These findings prove that terminators contribute to stereo matching, and constrain the type of neuronal mechanisms that might be responsible for the detection of terminator disparity.

  10. Simultaneous SLO/OCT imaging of the human retina with axial eye motion correction.

    PubMed

    Pircher, Michael; Baumann, Bernhard; Götzinger, Erich; Sattmann, Harald; Hitzenberger, Christoph K

    2007-12-10

    It has been shown that transversal scanning (or en-face) optical coherence tomography (TS-OCT) represents an imaging modality capable to record high isotropic resolution images of the human retina in vivo. However, axial eye motion still remains a challenging problem of this technique. In this paper we introduce a novel method to compensate for this eye motion. An auxiliary spectral domain partial coherence interferometer (SD-PCI) was integrated into an existing TS-OCT system and used to measure accurately the position of the cornea. A light source emitting at 1310nm was used in the additional interferometer which enabled a nearly loss free coupling of the two measurement beams via a dichroic mirror. The recorded corneal position was used to drive an additional voice coil translation stage in the reference arm of the TS-OCT system to correct for axial eye motion. Currently, the correction can be performed with an update rate of ~200Hz. The TS-OCT instrument is operated with a line scan rate of 4000 transversal lines per second which enables simultaneous SLO/OCT imaging at a frame rate of 40fps. 3D data of the human retina with isotropic high resolution, that was sufficient to visualize the human cone mosaic in vivo, is presented.

  11. Retinal toxicity related to hydroxychloroquine in patients with systemic lupus erythematosus and rheumatoid arthritis.

    PubMed

    Telek, Hande Husniye; Yesilirmak, Nilufer; Sungur, Gulten; Ozdemir, Yaprak; Yesil, Nesibe Karahan; Ornek, Firdevs

    2017-12-01

    To compare the retinal toxicity due to hydroxychloroquine (HCQ) use in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) using multifocal electroretinography (mfERG), fundus autofluorescence (FAF) and optical coherence tomography (OCT). Patients who were using HCQ due to SLE and RA, and healthy subjects evaluated in this study. Central foveal thickness (CFT), inner-outer segment (IS-OS) junction irregularity, retinal nerve fiber layer thickness, mfERG and FAF measurements were performed to evaluate retinal toxicity. Study included 35 eyes of 35 SLE patients, 40 eyes of 40 RA patients and 20 eyes of 20 healthy subjects. In SLE group, retinal abnormality was found in three eyes with mfERG, in one eye with FAF and in four eyes with OCT. In RA group, retinal abnormality was found in 10 eyes with mfERG, in five eyes with FAF and in nine eyes with OCT. A statistically significant difference was found with respect to mfERG between "eyes with abnormal responses and without abnormal responses" and "eyes with abnormal responses and controls" (p < 0.05). A statistically significant difference was found with respect to CFT between "eyes with IS-OS junction irregularities and without IS-OS junction irregularities" and "eyes with/without IS-OS junction irregularities and controls" (p < 0.05). The use of HCQ seems to cause retinal toxicity more often in RA patients compared to SLE patients. For the early detection of retinal changes, OCT and mfERG can be used as screening tools due to their higher sensitivity rates compared to other tests.

  12. Chronic dry eye in photorefractive keratectomy and laser in situ keratomileusis: Manifestations, incidence, and predictive factors.

    PubMed

    Bower, Kraig S; Sia, Rose K; Ryan, Denise S; Mines, Michael J; Dartt, Darlene A

    2015-12-01

    To evaluate dry-eye manifestations after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and determine the incidence and predictive factors of chronic dry eye using a set of dry-eye criteria. Walter Reed Army Medical Center, Washington, DC, USA. Prospective, non-randomized clinical study. Dry-eye evaluation was performed before and after surgery. Main outcome measures included dry-eye manifestations, incidence, and predictive factors of chronic dry eye. This study comprised 143 active-duty U.S. Army personnel, ages 29.9 ± 5.2 years, with myopia or myopic astigmatism (manifest spherical equivalent -3.83 ± 1.96 diopters) having PRK or LASIK. Schirmer scores, corneal sensitivity, ocular surface staining, surface regularity index, and responses to dry-eye questionnaire significantly changed over time after PRK. After LASIK, significant changes were observed in tear breakup time, corneal sensitivity, ocular surface staining, and responses to questionnaire. Twelve months postoperatively, 5.0% of PRK and 0.8% of LASIK participants developed chronic dry eye. Regression analysis showed that pre-operatively lower Schirmer score will significantly influence development of chronic dry eye after PRK, whereas preoperatively, lower Schirmer score or higher ocular surface staining score will significantly influence the occurrence of chronic dry eye after LASIK. Chronic dry eye was uncommon after PRK and LASIK. Ocular surface and tear-film characteristics during pre-operative examination might help to predict chronic dry-eye development in PRK and LASIK. The authors have no financial interest in any product, drug, instrument, or equipment discussed in this manuscript. Copyright © 2015 ASCRS and ESCRS. All rights reserved.

  13. Effectiveness of an Eyelid Thermal Pulsation Procedure to Treat Recalcitrant Dry Eye Symptoms After Laser Vision Correction.

    PubMed

    Schallhorn, Craig S; Schallhorn, Julie M; Hannan, Stephen; Schallhorn, Steven C

    2017-01-01

    To provide an initial retrospective evaluation of the effectiveness of a thermal pulsation system to treat intractable patient-reported dye eye symptoms following laser vision correction. A total of 109 eyes of 57 patients underwent thermal pulsation therapy (LipiFlow; TearScience, Morrisville, NC) for the treatment of dry eye symptoms following laser vision correction. A standardized dry eye questionnaire, the Standard Patient Evaluation of Eye Dryness (SPEED II), was administered to all patients before and after thermal pulsation therapy. The primary outcome was patient-reported dry eye symptoms as measured by this questionnaire. The mean patient age was 49 years (interquartile range [IQR]: 38 to 60), 70% were female, and the primary refractive procedure was LASIK (n = 91, 83%) or photorefractive keratectomy (PRK) (n = 18, 17%). Patients underwent thermal pulsation therapy at a mean of 40.5 months (IQR: 27.6 to 55.0) after the primary procedure. The mean pre-therapy SPEED II questionnaire score was 17.5 (IQR: 14 to 21), with a reduced mean post-therapy score of 10.2 (IQR: 6 to 14; 95% confidence interval [CI]: 8.8 to 11.5, P < .001). Patients with PRK tended to report more improvement. At the follow-up clinical evaluation, objective improvements were noted in tear break-up time (+1.9 sec; 95% CI: 1.3 to 2.5), reduction in grade of meibomian gland dysfunction (-0.69; 95% CI: -0.54 to -0.84), and corneal staining (-0.74; 95% CI: -0.57 to -0.91). In this initial retrospective evaluation, a significant improvement in patient-reported dry eye symptoms was observed following thermal pulsation therapy. This treatment modality may have utility in the management of dry eye symptoms following laser vision correction, but further study is needed to define its role. [J Refract Surg. 2017;33(1):30-36.]. Copyright 2017, SLACK Incorporated.

  14. Effects of genipin corneal crosslinking in rabbit corneas.

    PubMed

    Avila, Marcel Y; Narvaez, Mauricio; Castañeda, Juan P

    2016-07-01

    To evaluate the effect of genipin, a natural crosslinking agent, in rabbit eyes. Department of Ophthalmology, Universidad Nacional de Colombia Centro de Tecnologia Oftalmica, Bogotá, Colombia. Experimental study. Ex vivo rabbit eyes (16; 8 rabbits) were treated with genipin 1.00%, 0.50%, and 0.25% for 5 minutes with a vacuum device to increase corneal permeability. Penetration was evaluated using Scheimpflug pachymetry (Pentacam). In the in vivo model (20 rabbits; 1 eye treated, 1 eye with vehicle), corneas were crosslinked with genipin as described. Corneal curvature, corneal pachymetry, and intraocular pressure (IOP) assessments as well as slitlamp examinations were performed 0, 7, 30, and 60 days after treatment. In the ex vivo model, Scheimpflug pachymetry showed deep penetration in the rabbit corneas with an increase in corneal density and a dose-dependent relationship. Corneal flattening was observed in treated eyes (mean 4.4 diopters ± 0.5 [SD]) compared with the control eyes. Pachymetry and IOP were stable in all evaluations. No eye showed toxicity in the anterior chamber or in the lens. Corneal crosslinking induced by genipin produced significant flattening of the cornea with no toxicity in rabbit eyes. This crosslinking could be useful in the treatment of corneal ectasia and in the modification of corneal curvature. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. Preparation and clinical evaluation of succinylated collagen punctal plugs in dry eye syndrome: a pilot study.

    PubMed

    Hadassah, J; Bhuvaneshwari, Namita; Singh, Deepti; Sehgal, P K

    2010-01-01

    This is a pilot study of 10 eyes of 6 patients. This paper describes the preparation and clinical evaluation of succinylated collagen punctal plugs (SCPP) in the treatment of dry eye syndrome (DES). SCPP were prepared from succinylated collagen with the exact dimensions of the punctum (length 1.5-2.5 mm, diameter 0.2-0.5 mm, water content between 50 and 55%). All the patients were clinically evaluated for best corrected visual acuity (BCVA), tear fluid levels (TFL), protein content, tear fluid osmolarity (TFO), fluorescence staining of the cornea and tear break-up time (TBUT) before and after punctal occlusion with SCPP. TFL improved among all the patients after punctal occlusion with SCPP. BCVA showed improvement in case 4 (right eye/left eye), case 5 (left eye) and case 6 (right eye), who had developed dry eyes due to environmental conditions. Protein content increased on day 7 in all the patients and gradually decreased. TFO decreased on days 3 and 5 in all patients after punctal occlusion with SCPP, and showed the same levels on day 14. TFL, PC, TFO and TBUT showed significant improvement in all the patients after punctal occlusion with SCPP. All patients experienced symptomatic relief after punctal occlusion with SCPP. There was no discomfort, foreign body sensation, plug extrusion, corneal aberration, infection, or formation of pyogenic granuloma with SCPP. SCPP stands as a promising alternative to other punctal plugs in the treatment of DES. Copyright 2010 S. Karger AG, Basel.

  16. FogEye UV Sensor System Performance Characteristics

    DOT National Transportation Integrated Search

    2004-03-01

    The primary objective of the FogEye Evaluation Program is to determine whether coupled ultra-violet sources and detectors may provide enhancements to safety on the airport surface. The results of this effort will be used to complete the evaluation of...

  17. Noradrenergic modulation of masseter muscle activity during natural rapid eye movement sleep requires glutamatergic signalling at the trigeminal motor nucleus

    PubMed Central

    Schwarz, Peter B; Mir, Saba; Peever, John H

    2014-01-01

    Noradrenergic neurotransmission in the brainstem is closely coupled to changes in muscle activity across the sleep–wake cycle, and noradrenaline is considered to be a key excitatory neuromodulator that reinforces the arousal-related stimulus on motoneurons to drive movement. However, it is unknown if α-1 noradrenoceptor activation increases motoneuron responsiveness to excitatory glutamate (AMPA) receptor-mediated inputs during natural behaviour. We studied the effects of noradrenaline on AMPA receptor-mediated motor activity at the motoneuron level in freely behaving rats, particularly during rapid eye movement (REM) sleep, a period during which both AMPA receptor-triggered muscle twitches and periods of muscle quiescence in which AMPA drive is silent are exhibited. Male rats were subjected to electromyography and electroencephalography recording to monitor sleep and waking behaviour. The implantation of a cannula into the trigeminal motor nucleus of the brainstem allowed us to perfuse noradrenergic and glutamatergic drugs by reverse microdialysis, and thus to use masseter muscle activity as an index of motoneuronal output. We found that endogenous excitation of both α-1 noradrenoceptor and AMPA receptors during waking are coupled to motor activity; however, REM sleep exhibits an absence of endogenous α-1 noradrenoceptor activity. Importantly, exogenous α-1 noradrenoceptor stimulation cannot reverse the muscle twitch suppression induced by AMPA receptor blockade and nor can it elevate muscle activity during quiet REM, a phase when endogenous AMPA receptor activity is subthreshold. We conclude that the presence of an endogenous glutamatergic drive is necessary for noradrenaline to trigger muscle activity at the level of the motoneuron in an animal behaving naturally. PMID:24860176

  18. Odors enhance slow-wave activity in non-rapid eye movement sleep

    PubMed Central

    Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam

    2016-01-01

    Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9–15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5–4 Hz) and slow spindle (9–12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. PMID:26888107

  19. Odors enhance slow-wave activity in non-rapid eye movement sleep.

    PubMed

    Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam; Hairston, Ilana S

    2016-05-01

    Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9-15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5-4 Hz) and slow spindle (9-12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. Copyright © 2016 the American Physiological Society.

  20. The effect of three low-cost engineering treatments on driver fatigue: A driving simulator study.

    PubMed

    Merat, Natasha; Jamson, A Hamish

    2013-01-01

    Three engineering treatments were implemented in a driving simulator study to assess the effect of road-based measures on alleviating the symptoms of fatigue. Using results from previous research on the effect of circadian rhythms on fatigue-related crashes, two groups of male drivers were recruited for this study: young shift workers under the age of 35, who attended immediately after their night shift, and older drivers over the age of 45, who completed the study during the 'post lunch dip' period, after consuming lunch. Eye tracking (PERCLOS) and lateral driver performance measures were used to assess whether baseline measures of fatigue changed after drivers experienced each of the three treatments, which included variable message signs, chevrons and rumble strips. Results showed a marked difference in these measures between drivers' baseline (not fatigued) and experimental (fatigued) visits. There were also some reductions in lateral deviation and eye closure (as measured by PERCLOS) when the treatments were encountered, but no marked difference between the three treatments. These results suggest that in addition to driver- and vehicle-based methods currently employed to mitigate the effects of fatigue, the inclusion of such engineering measures may help alleviate fatigue-related impairments in driving, particularly if such treatments are implemented during long stretches of straight monotonous roads which are known to be associated with fatigue-related crashes. However, positive effects of the treatments were short lived, prompting the need for further investigations on their optimal frequency of presentation and combination to achieve maximum impact from these low-cost, road-based treatments. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  1. Visual impairment and road traffic accidents among drivers in Jimma Town, Southwest Ethiopia.

    PubMed

    Biza, Mohamed; Mossie, Andualem; Woldemichael, Kifle; Gelaw, Yeshigeta

    2013-04-01

    Vision play a vital role in driving where good and efficient visual functioning of the driver is essential. Any significant loss of visual function will diminish a driver's ability to operate a motor vehicle safely and will thus contribute to road traffic injury. However, there is little evidence indicating that defects of vision alone cause road traffic accidents. To determine the impact of visual impairment and other factors on road traffic accident among vehicle drivers. A cross-sectional descriptive study was conducted on 249 sampled drivers in Southwest Ethiopia. A pretested interviewer led questionnaire was used for interview and vision tests were done using Snellen's acuity chart and Ishihara pseudo-isochromatic plates. Statistical analyses were performed using SPSS version 16.0. The mean age of drivers was 33.6 years (SD +/- 10.3). The relative frequency of self reported road traffic accident was 15.3%. The prevalence of uncorrected binocular visual impairment was 1.6% and there was a significant association between visual impairment and road traffic accident (P < 0.05). Uncorrected refractive error was seen in 7.6% and 8.8% of drivers in the right and left eyes respectively, and 3.2% of them had vision less than what is required to obtain driving license (visual acuity of 6/12). None of the drivers with refractive errors were wearing appropriate corrections. Color vision impairment was seen in 1.6% of the drivers. A significant proportion (9.6%) of the drivers did not have eye exam for their driving license. Uncorrected binocular visual impairment was strongly associated with road traffic accident. There is need for consistent inspection and screening, strict rules and regulations of licensing and health education for drivers to minimize road traffic accident.

  2. FogEye UV Sensor System Evaluation : Phase I Report.

    DOT National Transportation Integrated Search

    2002-09-01

    FogEye technology uses the solar-blind reigion of the ultraviolet spectrum to develop sensors or systems that are unaffected by sunlight. The U.S. Congress asked the Federal Aviation Administration to investigate the feasibility of applying FogEye te...

  3. Retinal endoilluminator toxicity of xenon and light-emitting diode (LED) light source: rabbit model.

    PubMed

    Aydin, Bahri; Dinç, Erdem; Yilmaz, S Necat; Altiparmak, U Emrah; Yülek, Fatma; Ertekin, Sevda; Yilmaz, Mustafa; Yakın, Mehmet

    2014-09-01

    This study evaluates retinal toxicity due to endoillumination with the light-emitting diode (LED) light source in comparison to endoillumination with xenon light source. Twenty-five eyes of 14 New Zealand pigmented rabbits were used in the study. The LED light (Omesis Medical Systems, Turkey) group was composed of 7 right eyes, while the other 7 right eyes constituted the xenon group (420 nm filter, 357mW/cm(2)) (Bright Star; DORC, Zuidland, Netherlands). Eleven untreated left eyes composed the control group. Twenty gauge pars plana incision 1.5 mm behind the limbus was performed in the right eyes. Twenty gauge bullet type fiberoptic endoilluminator was inserted into the eye from the incision without any pars plana vitrectomy. Fiberoptic endoilluminator was placed in such a way that it was directed toward visual streak of the rabbit retina with a 5 mm distance to retinal surface. Endoillumination was then applied for 20 min with a maximum light intensity for LED and xenon light. In left control eyes, no surgical procedure and no endoillumination were performed. One week after the endoillumination procedure, both eyes of the rabbits were enucleated following electroretinography. Sections stained with hematoxylin and eosin to evaluate morphologic changes. Retina tissues were assessed by active caspase-3 staining. There was no difference in the shape of the waveforms recorded in the eyes endoilluminated with LED light and xenon light sources compared to control eyes both before and after endoillumination application (p > 0.05). Microscopic evaluation of the retinas with hematoxylin and eosin staining demonstrated that all study groups have normal histologic properties similar to control group. No apoptosis positive cells were found within all sections in all groups. When the LED light source is used with maximum power and limited duration for endoillumination in rabbit eyes it does not produce phototoxic effects that may be detectable by electrophysiology and histology similar to xenon light.

  4. Decision tool for clients with medical issues: a framework for identifying driving risk and potential to return to driving.

    PubMed

    Dickerson, Anne E; Bédard, Michel

    2014-04-01

    This paper offers occupational therapy generalists and specialists a new framework by which to consider clinical evaluation data and an older adult's driving risk and potential to resume this previously learned skill. Based on Michon's model describing the hierarchy of driving levels, clinical questions identify the factors that may affect a client's fitness to drive. The first part is intended to support clinical judgment of whether a client needs a driving evaluation by a driver rehabilitation specialist. The second part offers a framework to organize clinical data that are already known and determine what other evaluation information is justified and necessary to make a driving recommendation. Methods and rational for use are discussed.

  5. Effectiveness evaluation of simulative workshops for newly licensed drivers.

    PubMed

    Rosenbloom, Tova; Eldror, Ehud

    2014-02-01

    The current study set to examine the effects of simulator use in driving instruction on newly licensed drivers, comparing the road safety knowledge and reported intended behavior, as well as the actual driving performance of new drivers. Participants consisted of 280 newly licensed driver, of which 140 whose drivers license training included additional simulator-based lessons, and 140 drivers whose training precluded simulator-based lessons. All drivers answered questionnaires pertaining to their intended safe driving behaviors (according to Ajzen's (2000) theory of planned behavior), and to their traffic safety knowledge. Of the initial sample, 40 drivers received actual driving performance evaluation by an expert driving instructor, as well as by in-vehicle data recorders (IVDRs). We assumed that safer drivers report safer driving intentions, demonstrate greater traffic safety knowledge, evaluated as safer drivers by the driving instructor, and display lower and stable driving parameters on the IVDRs. We hypothesized that theoretical driving studies combined with practical training on simulators will elevate the safety level of novices driving. Hierarchical regression analyses on driving intentions indicated that drivers who did not receive simulator-based lessons demonstrated safer driving intentions compared to drivers who received simulator-based lessons. This pattern possibly indicating the drivers who received simulator-based lessons felt more confident in their driving abilities compared to drivers who did not receive simulated training. No significant difference was found in traffic safety knowledge, or in the evaluation of the expert driving instructor. IDVR data comparisons indicated drivers who received simulator-based lessons braked more often and were less prone to headway events, suggesting a more responsive driving style. These findings do not point to any significant advantage or disadvantage of the current simulator-based driving training over other driving training methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes.

    PubMed

    Popelka, Stanislav; Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

    2016-01-01

    The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe.

  7. EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes

    PubMed Central

    Stachoň, Zdeněk; Šašinka, Čeněk; Doležalová, Jitka

    2016-01-01

    The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe. PMID:27087805

  8. Eye Movement Patterns in Natural Reading: A Comparison of Monolingual and Bilingual Reading of a Novel

    PubMed Central

    Cop, Uschi; Drieghe, Denis; Duyck, Wouter

    2015-01-01

    Introduction and Method This paper presents a corpus of sentence level eye movement parameters for unbalanced bilingual first language (L1) and second-language (L2) reading and monolingual reading of a complete novel (56 000 words). We present important sentence-level basic eye movement parameters of both bilingual and monolingual natural reading extracted from this large data corpus. Results and Conclusion Bilingual L2 reading patterns show longer sentence reading times (20%), more fixations (21%), shorter saccades (12%) and less word skipping (4.6%), than L1 reading patterns. Regression rates are the same for L1 and L2 reading. These results could indicate, analogous to a previous simulation with the E-Z reader model in the literature, that it is primarily the speeding up of lexical access that drives both L1 and L2 reading development. Bilingual L1 reading does not differ in any major way from monolingual reading. This contrasts with predictions made by the weaker links account, which predicts a bilingual disadvantage in language processing caused by divided exposure between languages. PMID:26287379

  9. Binocular visual training to promote recovery from monocular deprivation.

    PubMed

    Murphy, Kathryn M; Roumeliotis, Grayson; Williams, Kate; Beston, Brett R; Jones, David G

    2015-01-08

    Abnormal early visual experience often leads to poor vision, a condition called amblyopia. Two recent approaches to treating amblyopia include binocular therapies and intensive visual training. These reflect the emerging view that amblyopia is a binocular deficit caused by increased neural noise and poor signal-in-noise integration. Most perceptual learning studies have used monocular training; however, a recent study has shown that binocular training is effective for improving acuity in adult human amblyopes. We used an animal model of amblyopia, based on monocular deprivation, to compare the effect of binocular training either during or after the critical period for ocular dominance plasticity (early binocular training vs. late binocular training). We used a high-contrast, orientation-in-noise stimulus to drive the visual cortex because neurophysiological findings suggest that binocular training may allow the nondeprived eye to teach the deprived eye's circuits to function. We found that both early and late binocular training promoted good visual recovery. Surprisingly, we found that monocular deprivation caused a permanent deficit in the vision of both eyes, which became evident only as a sleeper effect following many weeks of visual training. © 2015 ARVO.

  10. Initial component control in disparity vergence: a model-based study.

    PubMed

    Horng, J L; Semmlow, J L; Hung, G K; Ciuffreda, K J

    1998-02-01

    The dual-mode theory for the control of disparity-vergence eye movements states that two components control the response to a step change in disparity. The initial component uses a motor preprogram to drive the eyes to an approximate final position. This initial component is followed by activation of a late component operating under visual feedback control that reduces residual disparity to within fusional limits. A quantitative model based on a pulse-step controller, similar to that postulated for saccadic eye movements, has been developed to represent the initial component. This model, an adaptation of one developed by Zee et al. [1], provides accurate simulations of isolated initial component movements and is compatible with the known underlying neurophysiology and existing neurophysiological data. The model has been employed to investigate the difference in dynamics between convergent and divergent movements. Results indicate that the pulse-control component active in convergence is reduced or absent from the control signals of divergence movements. This suggests somewhat different control structures of convergence versus divergence, and is consistent with other directional asymmetries seen in horizontal vergence.

  11. Sensitivity of vergence responses of 5- to 10-week-old human infants

    PubMed Central

    Seemiller, Eric S.; Wang, Jingyun; Candy, T. Rowan

    2016-01-01

    Infants have been shown to make vergence eye movements by 1 month of age to stimulation with prisms or targets moving in depth. However, little is currently understood about the threshold sensitivity of the maturing visual system to such stimulation. In this study, 5- to 10-week-old human infants and adults viewed a target moving in depth as a triangle wave of three amplitudes (1.0, 0.5, and 0.25 meter angles). Their horizontal eye position and the refractive state of both eyes were measured simultaneously. The vergence responses of the infants and adults varied at the same frequency as the stimulus at the three tested modulation amplitudes. For a typical infant of this age, the smallest amplitude is equivalent to an interocular change of approximately 2° of retinal disparity, from nearest to farthest points. The infants' accommodation responses only modulated reliably to the largest stimulus, while adults responded to all three amplitudes. Although the accommodative system appears relatively insensitive, the sensitivity of the vergence responses suggests that subtle cues are available to drive vergence in the second month after birth. PMID:26891827

  12. Ethical and Pedagogical Issues in the Use of Simulation Activities in the Classroom: Evaluating the "Blue Eyes-Brown Eyes" Prejudice Simulation.

    ERIC Educational Resources Information Center

    Byrnes, Deborah A.; Kiger, Gary

    The effectiveness of a well-known prejudice-reduction simulation activity, "Blue Eyes-Brown Eyes," was assessed as a tool for changing the attitudes of nonblack teacher education students toward blacks. The subjects were 164 students enrolled in eight sections of an introductory elementary education course at a state university. Three…

  13. Riot Control Agents

    DTIC Science & Technology

    2009-01-01

    However, a local anesthetic applied to the eye will help with eye pain and allow for further evaluation of the eye by slit lamp. Contact lenses...RCAs. Eye findings from RCA toxicity can range in severity from conjunctival erythema to ocular necrosis . Lacrimation, conjunctival erythema/edema...and ocular necrosis (Grant, 1986). Figure 12.12 illustrates and summarizes the common toxic ophthalmological signs and symptoms associated with

  14. Fundus autofluorescence patterns in primary intraocular lymphoma.

    PubMed

    Casady, Megan; Faia, Lisa; Nazemzadeh, Maryam; Nussenblatt, Robert; Chan, Chi-Chao; Sen, H Nida

    2014-02-01

    To evaluate fundus autofluorescence (FAF) patterns in patients with primary intraocular (vitreoretinal) lymphoma. Records of all patients with primary intraocular lymphoma who underwent FAF imaging at the National Eye Institute were reviewed. Fundus autofluorescence patterns were evaluated with respect to clinical disease status and the findings on fluorescein angiography and spectral-domain optical coherence tomography. There were 18 eyes (10 patients) with primary intraocular lymphoma that underwent FAF imaging. Abnormal autofluorescence in the form of granular hyperautofluorescence and hypoautofluorescence was seen in 11 eyes (61%), and blockage by mass lesion was seen in 2 eyes (11%). All eyes with granular pattern on FAF had active primary intraocular lymphoma at the time of imaging, but there were 5 eyes with unremarkable FAF, which were found to have active lymphoma. The most common pattern on fluorescein angiography was hypofluorescent round spots with a "leopard spot" appearance (43%). These hypofluorescent spots on fluorescein angiography correlated with hyperautofluorescent spots on FAF in 5 eyes (36%) (inversion of FAF). Nodular hyperreflective spots at the level of retinal pigment epithelium on optical coherence tomography were noted in 43% of eyes. The hyperautofluorescent spots on FAF correlated with nodular hyperreflective spots on optical coherence tomography in 6 eyes (43%). Granularity on FAF was associated with active lymphoma in majority of the cases. An inversion of FAF (hyperautofluorescent spots on FAF corresponding to hypofluorescent spots on fluorescein angiography) was observed in less than half of the eyes.

  15. Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study.

    PubMed

    Kamiya, K; Nakanishi, M; Ishii, R; Kobashi, H; Igarashi, A; Sato, N; Shimizu, K

    2012-10-01

    To assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome. This study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events. We found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes. In dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

  16. Mapping owl's eye cells of patients with cytomegalovirus corneal endotheliitis using in vivo laser confocal microscopy.

    PubMed

    Yokogawa, Hideaki; Kobayashi, Akira; Sugiyama, Kazuhisa

    2013-01-01

    To produce a two-dimensional reconstruction map of owl's eye cells using in vivo laser confocal microscopy in patients with cytomegalovirus (CMV) corneal endotheliitis, and to demonstrate any association between owl's eye cells and coin-shaped lesions observed with slit-lamp biomicroscopy. Two patients (75- and 77-year-old men) with polymerase chain reaction-proven CMV corneal endotheliitis were evaluated in this study. Slit-lamp biomicroscopy and in vivo laser confocal microscopy were performed. Images of owl's eye cells in the endothelial cell layer were arranged and mapped into subconfluent montages. Montage images of owl's eye cells were then superimposed on a slit-lamp photo of the corresponding coin-shaped lesion. Degree of concordance between the confocal microscopic images and slit-lamp photos was evaluated. In both eyes, a two-dimensional reconstruction map of the owl's eye cells was created by computer software using acquired confocal images; the maps showed circular patterns. Superimposing montage images of owl's eye cells onto the photos of a coin-shaped lesion showed good concordance in the two eyes. This study suggests that there is an association between owl's eye cells observed by confocal microscopy and coin-shaped lesions observed by slit-lamp biomicroscopy in patients with CMV corneal endotheliitis. The use of in vivo laser confocal microscopy may provide clues as to the underlying causes of CMV corneal endotheliitis.

  17. Beneficial effect of daidzin in dry eye rat model through the suppression of inflammation and oxidative stress in the cornea.

    PubMed

    Xiao, Fan; Cui, Hua; Zhong, Xiao

    2018-05-01

    Present investigation evaluates the effect of daidzin in dry eye rat model through the suppression of inflammation and oxidative stress in the cornea. Briefly, electron spine resonance was used for the estimation of radical scavenging activity of daidzin and COX Fluorescent Activity Assay Kit was used for the estimation of PGS activity. Dry eye rat model was developed by removing the lacrimal gland and effect of daidzin was evaluated in dry eye rat model by estimating the fluorescein score, tear volume and expressions of heme oxigenase (HO-1), TNF α, Interlukin 6 (IL-6), matrix metallopeptidase 9 (MMP-9) and PGS-2. Result of the present study suggested that daidzin possess tyrosyl radical scavenging activity and thereby decreases the oxidative stress. Activity of PGS significantly increases in dry eye which was inhibited by daidzin treatment due to competitive inhibition of PGS. It also recovers the tear volume in dry eye rat model in which lacrimal gland was removed. Thus corneal erosion was improved by daidzin in dry eye rat model. Thus present study concludes that treatment with daidzin protects the cornea in dry eye rat model by suppression inflammation and oxidative stress.

  18. Dry Eye Disease following Refractive Surgery: A 12-Month Follow-Up of SMILE versus FS-LASIK in High Myopia

    PubMed Central

    Wang, Bingjie; Chu, Renyuan; Dai, Jinhui; Qu, Xiaomei; Zhou, Hao

    2015-01-01

    Purpose. To compare dry eye disease following SMILE versus FS-LASIK. Design. Prospective, nonrandomised, observational study. Patients. 90 patients undergoing refractive surgery for myopia were included. 47 eyes underwent SMILE and 43 eyes underwent FS-LASIK. Methods. Evaluation of dry eye disease was conducted preoperatively and at 1, 3, 6, and 12 months postoperatively, using the Salisbury Eye Evaluation Questionnaire (SEEQ) and TBUT. Results. TBUT reduced following SMILE at 1 and 3 months (p < 0.001) and at 1, 3, and 6 months following FS-LASIK (p < 0.001). TBUT was greater following SMILE than FS-LASIK at 3, 6, and 12 months (p < 0.001, p < 0.001, and p = 0.009, resp.). SEEQ scores increased (greater symptoms) following SMILE at 1 month (p < 0.001) and 3 months (p = 0.003) and at 1, 3, and 6 months following FS-LASIK (p < 0.001). SMILE produced lower SEEQ scores (fewer symptoms) than FS-LASIK at 1, 3, and 6 months (p < 0.001). Conclusion. SMILE produces less dry eye disease than FS-LASIK at 6 months postoperatively but demonstrates similar degrees of dry eye disease at 12 months. PMID:26649190

  19. Optical Coherence Tomography Imaging of the Palisades of Vogt to Assist Clinical Evaluation and Surgical Planning in a Case of Limbal Stem-Cell Deficiency.

    PubMed

    Espandar, Ladan; Steele, Jessica F; Lathrop, Kira L

    2017-09-01

    To describe the use of volumetric optical coherence tomography (OCT) imaging to assist evaluation of a patient referred for autologous limbal stem-cell transplant. This is a case report of a 50-year-old patient presenting with unilateral limbal stem-cell deficiency who was referred for autologous limbal stem-cell transplant. The presence of Salzmann nodules in the donor eye raised questions about the efficacy of transplantation, prompting examination of both eyes using volumetric OCT imaging to determine whether there were palisades of Vogt (POV) present. Image volumes were acquired in all clock hours and were compared against those of an age-matched normal subject. Palisades were found in both eyes, although in both eyes there were fewer palisade ridges, and those that were present were not as distinct as those of the normal subject. The OCT volumes also showed that stromal scarring was present only in the anterior stroma of the intended transplant eye. These findings suggested that the patient may be able to sustain a deep anterior lamellar keratoplasty without an autologous transplant, which would spare any insult to the opposing eye and require less surgery to restore vision in the affected eye. Nine months postsurgical follow-up revealed significant improvement in visual acuity and no scar tissue development. The OCT evaluation of the POV provides detailed information to the clinician that may assist in diagnosis and evaluation of patients before transplantation. Further development of this technique is necessary to make it clinically available.

  20. APPLICATION OF EYE TRACKING FOR MEASUREMENT AND EVALUATION IN HUMAN FACTORS STUDIES IN CONTROL ROOM MODERNIZATION

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kovesdi, C.; Spielman, Z.; LeBlanc, K.

    An important element of human factors engineering (HFE) pertains to measurement and evaluation (M&E). The role of HFE-M&E should be integrated throughout the entire control room modernization (CRM) process and be used for human-system performance evaluation and diagnostic purposes with resolving potential human engineering deficiencies (HEDs) and other human machine interface (HMI) design issues. NUREG-0711 describes how HFE in CRM should employ a hierarchical set of measures, particularly during integrated system validation (ISV), including plant performance, personnel task performance, situation awareness, cognitive workload, and anthropometric/ physiological factors. Historically, subjective measures have been primarily used since they are easier to collectmore » and do not require specialized equipment. However, there are pitfalls with relying solely on subjective measures in M&E such that negatively impact reliability, sensitivity, and objectivity. As part of comprehensively capturing a diverse set of measures that strengthen findings and inferences made of the benefits from emerging technologies like advanced displays, this paper discusses the value of using eye tracking as an objective method that can be used in M&E. A brief description of eye tracking technology and relevant eye tracking measures is provided. Additionally, technical considerations and the unique challenges with using eye tracking in full-scaled simulations are addressed. Finally, this paper shares preliminary findings regarding the use of a wearable eye tracking system in a full-scale simulator study. These findings should help guide future full-scale simulator studies using eye tracking as a methodology to evaluate human-system performance.« less

  1. Patient-reported outcomes 5 years after laser in situ keratomileusis.

    PubMed

    Schallhorn, Steven C; Venter, Jan A; Teenan, David; Hannan, Stephen J; Hettinger, Keith A; Pelouskova, Martina; Schallhorn, Julie M

    2016-06-01

    To assess vision-related, quality-of-life outcomes 5 years after laser in situ keratomileusis (LASIK) and determine factors predictive of patient satisfaction. Optical Express, Glasgow, Scotland. Retrospective case series. Data from patients who had attended a clinical examination 5 years after LASIK were analyzed. All treatments were performed using the Visx Star S4 IR excimer laser. Patient-reported satisfaction, the effect of eyesight on various activities, visual phenomena, and ocular discomfort were evaluated 5 years postoperatively. Multivariate regression analysis was performed to determine factors affecting patient satisfaction. The study comprised 2530 patients (4937 eyes) who had LASIK. The mean age at the time of surgery was 42.4 years ± 12.5 (SD), and the preoperative manifest spherical equivalent ranged from -11.0 diopters (D) to +4.88 D. Five years postoperatively, 79.3% of eyes were within ±0.50 D of emmetropia and 77.7% of eyes achieved monocular uncorrected distance visual acuity (UDVA) and 90.6% of eyes achieved binocular UDVA of 20/20 or better. Of the patients, 91.0% said they were satisfied with their vision and 94.9% did not wear distance correction. Less than 2.0% of patients noticed visual phenomena, even with spectacle correction. Major predictors of patient satisfaction 5 years postoperatively were postoperative binocular UDVA (37.6% variance explained by regression model), visual phenomena (relative contribution of 15.0%), preoperative and postoperative sphere and their interactions (11.6%), and eyesight-related difficulties with various activities such as night driving, outdoor activities, and reading (10.2%). Patient-reported quality-of-life and satisfaction rates remained high 5 years after LASIK. Uncorrected vision was the strongest predictor of satisfaction. Dr. S.C. Schallhorn is a consultant to Abbott Medical Optics, Inc., Zeiss Meditec AG, and Autofocus Inc. and a global medical director for Optical Express. No other author has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  2. Evaluation of treatment for dry eye with 2-hydroxyestradiol using a dry eye rat model.

    PubMed

    Higuchi, Akihiro; Oonishi, Erina; Kawakita, Tetsuya; Tsubota, Kazuo

    2016-01-01

    2-hydroxy estradiol (2-OHE2) is a catechol derivative of 17β -Estradiol (E2) and it is synthesized from E2 catalyzed by cytochrome P4501A1. Previous studies reported that 2-OHE2 is a physiologic antioxidant in lipoproteins, liver microsomes, and the brain. Catechol derivatives show an anti-inflammatory effect through the inhibition of prostaglandin endoperoxide synthase (PGS) activity. Corneal erosion caused by dry eye is related to an increase in oxidative stress and inflammation in ocular surface cells. We investigated the therapeutic effects of 2-OHE2 on corneal damage caused by dry eye. Steroidal radical scavenging activity was confirmed through the electron spin resonance (ESR) method. PGS activity was measured using the COX Fluorescent Activity Assay Kit. To evaluate the effect of 2-OHE2 on the treatment for dry eye, 2-OHE2 was applied as an eye drop experiment using dry eye model rats. 2-OHE2 scavenged tyrosyl radical and possibly suppressed oxidative stress in corneal epithelial cells. In addition, 2-OHE2 inhibited PGS activity, and 2-OHE2 is probably a competitive inhibitor of PGS. Corneal PGS activity was upregulated in the dry eye group. Therefore, 2-OHE2 eye drops improved corneal erosion in dry eye model rats. 2-OHE2 is a candidate for the treatment of dry eye through the suppression of inflammation and oxidative stress in the cornea.

  3. The effects of practice with MP3 players on driving performance.

    PubMed

    Chisholm, S L; Caird, J K; Lockhart, J

    2008-03-01

    This study examined the effects of repeated iPod interactions on driver performance to determine if performance decrements decreased with practice. Nineteen younger drivers (mean age=19.4, range 18-22) participated in a seven session study in the University of Calgary Driving Simulator (UCDS). Drivers encountered a number of critical events on the roadways while interacting with an iPod including a pedestrian entering the roadway, a vehicle pullout, and a lead vehicle braking. Measures of hazard response, vehicle control, eye movements, and secondary task performance were analyzed. Increases in perception response time (PRT) and collisions were found while drivers were performing the difficult iPod tasks, which involved finding a specific song within the song titles menu. Over the course of the six experimental sessions, driving performance improved in all conditions. Difficult iPod interactions significantly increased the amount of visual attention directed into the vehicle above that of the baseline condition. With practice, slowed responses to driving hazards while interacting with the iPod declined somewhat, but a decrement still remained relative to the baseline condition. The multivariate results suggest that access to difficult iPod tasks while vehicles are in motion should be curtailed.

  4. Predictive validity of driving-simulator assessments following traumatic brain injury: a preliminary study.

    PubMed

    Lew, Henry L; Poole, John H; Lee, Eun Ha; Jaffe, David L; Huang, Hsiu-Chen; Brodd, Edward

    2005-03-01

    To evaluate whether driving simulator and road test evaluations can predict long-term driving performance, we conducted a prospective study on 11 patients with moderate to severe traumatic brain injury. Sixteen healthy subjects were also tested to provide normative values on the simulator at baseline. At their initial evaluation (time-1), subjects' driving skills were measured during a 30-minute simulator trial using an automated 12-measure Simulator Performance Index (SPI), while a trained observer also rated their performance using a Driving Performance Inventory (DPI). In addition, patients were evaluated on the road by a certified driving evaluator. Ten months later (time-2), family members observed patients driving for at least 3 hours over 4 weeks and rated their driving performance using the DPI. At time-1, patients were significantly impaired on automated SPI measures of driving skill, including: speed and steering control, accidents, and vigilance to a divided-attention task. These simulator indices significantly predicted the following aspects of observed driving performance at time-2: handling of automobile controls, regulation of vehicle speed and direction, higher-order judgment and self-control, as well as a trend-level association with car accidents. Automated measures of simulator skill (SPI) were more sensitive and accurate than observational measures of simulator skill (DPI) in predicting actual driving performance. To our surprise, the road test results at time-1 showed no significant relation to driving performance at time-2. Simulator-based assessment of patients with brain injuries can provide ecologically valid measures that, in some cases, may be more sensitive than a traditional road test as predictors of long-term driving performance in the community.

  5. Promoting organ donation through an entertainment-education TV program in Korea: Open Your Eyes.

    PubMed

    Byoung Kwan Lee; Hyun Soon Park; Choi, Myung-Il; Cheon Soo Kim

    2010-01-01

    The purpose of this study is to investigate the effects of the characteristics of the program, Open Your Eyes, an entertainment-education TV program in Korea, on parasocial interaction and behavioral intention for organ donation. The results indicated that affective evaluation positively affected parasocial interaction with the program but cognitive evaluation negatively affected involvement with beneficiaries in the program. Also, it was found that cognitive evaluation of Open Your Eyes had a significant positive effect on behavioral intention. In addition, a significant positive effect of program engagement on the behavioral intention was found. Thus, the results indicate that individuals who feel program engagement of Open Your Eyes will be more likely to proceed with organ donation. However, no direct effect of involvement with the beneficiary and program hosts was found.

  6. Dry-Enzyme Test For Gaseous Chemicals

    NASA Technical Reports Server (NTRS)

    Barzana, Eduardo; Karel, Marcus; Klibanov, Alexander

    1990-01-01

    Simple, dry-chemical test detects ethanol in human breath. Method of test also adapted to detection of such toxic chemicals as formaldehyde in airstreams. Used qualitatively to detect chemical compounds above present level; for example, ethanol above legal level for driving. Also used to indicate quantitatively concentrations of compounds. Involves dry enzyme and color indicator. Adapted to detect any gaseous compound transformed by enzymes to produce change evident to human eye or to instrument.

  7. Neuroscience-Enabled Complex Visual Scene Understanding

    DTIC Science & Technology

    2012-04-12

    some cases, it is hard to precisely say where or what we are looking at since a complex task governs eye fixations, for example in driving. While in...another objects ( say a door) can be resolved using the prior information about the scene. This knowledge can be provided from gist models, such as one...separation and combination of class-dependent features for handwriting recognition,” IEEE Trans. Pattern Anal. Mach. Intell., vol. 21, no. 10, pp. 1089

  8. Continued driving and time to transition to nondriver status through error-specific driving restrictions.

    PubMed

    Freund, Barbara; Petrakos, Davithoula

    2008-01-01

    We developed driving restrictions that are linked to specific driving errors, allowing cognitively impaired individuals to continue to independently meet mobility needs while minimizing risk to themselves and others. The purpose of this project was to evaluate the efficacy and duration expectancy of these restrictions in promoting safe continued driving. We followed 47 drivers age 60 years and older for 18 months, evaluating driving performance at 6-month intervals. Results demonstrated restricted drivers had safety profiles similar to safe drivers and gained additional driving time to transition to nondrivers.

  9. DNA methylation modulates H19 and IGF2 expression in porcine female eye

    PubMed Central

    Wang, Dongxu; Wang, Guodong; Yang, Hao; Liu, Haibo; Li, Cuie; Li, Xiaolan; Lin, Chao; Song, Yuning; Li, Zhanjun; Liu, Dianfeng

    2017-01-01

    Abstract The sexually dimorphic expression of H19/IGF2 is evolutionarily conserved. To investigate whether the expression of H19/IGF2 in the female porcine eye is sex-dependent, gene expression and methylation status were evaluated using quantitative real-time PCR (qPCR) and bisulfite sequencing PCR (BSP). We hypothesized that H19/IGF2 might exhibit a different DNA methylation status in the female eye. In order to evaluate our hypothesis, parthenogenetic (PA) cells were used for analysis by qPCR and BSP. Our results showed that H19 and IGF2 were over-expressed in the female eye compared with the male eye (3-fold and 2-fold, respectively). We observed a normal monoallelic methylation pattern for H19 differentially methylated regions (DMRs). Compared with H19 DMRs, IGF2 DMRs showed a different methylation pattern in the eye. Taken together, these results suggest that elevated expression of H19/IGF2 is caused by a specific chromatin structure that is regulated by the DNA methylation status of IGF2 DMRs in the female eye. PMID:28266684

  10. A Sticky Situation.

    PubMed

    Weng, Christina Y; Khimani, Karima S; Foroozan, Rod; Gospe, Sidney M; Bhatti, M Tariq

    2018-04-26

    An 81-year-old man with bilateral progressively blurry vision and optic disc swelling was referred for evaluation. Examination and ancillary testing confirmed a diagnosis of bilateral vitreopapillary traction (VPT) accompanied by unilateral tractional retinoschisis in the right eye. Pars plana vitrectomy was performed to release the traction in both eyes. Visual acuity improved in the right eye and stabilized in the left eye. Retinoschisis in the right eye resolved. The visual field improved in both eyes, although the left eye demonstrated a persistent hemifield defect likely attributable to a prior optic neuropathy. Distinguishing VPT optic neuropathy (VPTON) from nonarteritic anterior ischemic optic neuropathy (NAION) is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Capsular bag opacification after experimental implantation of a new accommodating intraocular lens in rabbit eyes.

    PubMed

    Werner, Liliana; Pandey, Suresh K; Izak, Andrea M; Vargas, Luis G; Trivedi, Rupal H; Apple, David J; Mamalis, Nick

    2004-05-01

    To evaluate the development of capsular bag opacification in rabbit eyes after implantation of an intraocular lens (IOL) designed to minimize contact between the anterior capsule and the IOL and ensure expansion of the capsular bag. David J. Apple, MD Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Ten New Zealand white rabbits had a study IOL (new accommodating silicone IOL [Synchrony, Visiogen, Inc.]) implanted in 1 eye and a control IOL (1-piece plate silicone IOL with large fixation holes) implanted in the other eye. Intraocular lens position, anterior capsule opacification (ACO), and posterior capsule opacification (PCO) were qualitatively assessed using slitlamp retroillumination photographs of the dilated eyes. Anterior capsule opacification and PCO were graded on a 0 to 4 scale after the eyes were enucleated (Miyake-Apple posterior and anterior views after excision of the cornea and iris). The eyes were also evaluated histopathologically. The rate of ACO and PCO was significantly higher in the control group. Fibrosis and ACO were almost absent in the study group; the control group exhibited extensive capsulorhexis contraction, including capsulorhexis occlusion. Postoperative IOL dislocation into the anterior chamber and pupillary block syndrome were observed in some eyes in the study group. The special design features associated with the study IOL appeared to help prevent PCO. Complications in the study group were probably caused by the increased posterior vitreous pressure in rabbit eyes compared to human eyes and the relatively large size of the study IOL relative to the anterior segment of rabbit eyes.

  12. Judgments at Gaze Value: Gaze Cuing in Banner Advertisements, Its Effect on Attention Allocation and Product Judgments.

    PubMed

    Palcu, Johanna; Sudkamp, Jennifer; Florack, Arnd

    2017-01-01

    Banner advertising is a popular means of promoting products and brands online. Although banner advertisements are often designed to be particularly attention grabbing, they frequently go unnoticed. Applying an eye-tracking procedure, the present research aimed to (a) determine whether presenting human faces (static or animated) in banner advertisements is an adequate tool for capturing consumers' attention and thus overcoming the frequently observed phenomenon of banner blindness, (b) to examine whether the gaze of a featured face possesses the ability to direct consumers' attention toward specific elements (i.e., the product) in an advertisement, and (c) to establish whether the gaze direction of an advertised face influences consumers subsequent evaluation of the advertised product. We recorded participants' eye gaze while they viewed a fictional online shopping page displaying banner advertisements that featured either no human face or a human face that was either static or animated and involved different gaze directions (toward or away from the advertised product). Moreover, we asked participants to subsequently evaluate a set of products, one of which was the product previously featured in the banner advertisement. Results showed that, when advertisements included a human face, participants' attention was more attracted by and they looked longer at animated compared with static banner advertisements. Moreover, when a face gazed toward the product region, participants' likelihood of looking at the advertised product increased regardless of whether the face was animated or not. Most important, gaze direction influenced subsequent product evaluations; that is, consumers indicated a higher intention to buy a product when it was previously presented in a banner advertisement that featured a face that gazed toward the product. The results suggest that while animation in banner advertising constitutes a salient feature that captures consumers' visual attention, gaze cuing can be an effective tool for driving viewers' attention toward specific elements in the advertisement and even shaping consumers' intentions to purchase the advertised product.

  13. Judgments at Gaze Value: Gaze Cuing in Banner Advertisements, Its Effect on Attention Allocation and Product Judgments

    PubMed Central

    Palcu, Johanna; Sudkamp, Jennifer; Florack, Arnd

    2017-01-01

    Banner advertising is a popular means of promoting products and brands online. Although banner advertisements are often designed to be particularly attention grabbing, they frequently go unnoticed. Applying an eye-tracking procedure, the present research aimed to (a) determine whether presenting human faces (static or animated) in banner advertisements is an adequate tool for capturing consumers’ attention and thus overcoming the frequently observed phenomenon of banner blindness, (b) to examine whether the gaze of a featured face possesses the ability to direct consumers’ attention toward specific elements (i.e., the product) in an advertisement, and (c) to establish whether the gaze direction of an advertised face influences consumers subsequent evaluation of the advertised product. We recorded participants’ eye gaze while they viewed a fictional online shopping page displaying banner advertisements that featured either no human face or a human face that was either static or animated and involved different gaze directions (toward or away from the advertised product). Moreover, we asked participants to subsequently evaluate a set of products, one of which was the product previously featured in the banner advertisement. Results showed that, when advertisements included a human face, participants’ attention was more attracted by and they looked longer at animated compared with static banner advertisements. Moreover, when a face gazed toward the product region, participants’ likelihood of looking at the advertised product increased regardless of whether the face was animated or not. Most important, gaze direction influenced subsequent product evaluations; that is, consumers indicated a higher intention to buy a product when it was previously presented in a banner advertisement that featured a face that gazed toward the product. The results suggest that while animation in banner advertising constitutes a salient feature that captures consumers’ visual attention, gaze cuing can be an effective tool for driving viewers’ attention toward specific elements in the advertisement and even shaping consumers’ intentions to purchase the advertised product. PMID:28626436

  14. The attentional blink in amblyopia.

    PubMed

    Popple, Ariella V; Levi, Dennis M

    2008-10-31

    Amblyopia is a disorder of visual acuity in one eye, thought to arise from suppression by the other eye during development of the visual cortex. In the attentional blink, the second of two targets (T2) in a Rapid Serial Visual Presentation (RSVP) stream is difficult to detect and identify when it appears shortly but not immediately after the first target (T1). We investigated the attentional blink seen through amblyopic eyes and found that it was less finely tuned in time than when the 12 amblyopic observers viewed the stimuli with their preferred eyes. T2 performance was slightly better through amblyopic eyes two frames after T1 but worse one frame after T1. Previously (A. V. Popple & D. M. Levi, 2007), we showed that when the targets were red letters in a stream of gray letters (or vice versa), normal observers frequently confused T2 with the letters before and after it (neighbor errors). Observers viewing through their amblyopic eyes made significantly fewer neighbor errors and more T2 responses consisting of letters that were never presented. In normal observers, T1 (on the rare occasions when it was reported incorrectly) was often confused with the letter immediately after it. Viewing through their amblyopic eyes, observers with amblyopia made more responses to the letter immediately before T1. These results suggest that childhood suppression of the input from amblyopic eyes disrupts attentive processing. We hypothesize reduced connectivity between monocularly tuned lower visual areas, subcortical structures that drive foveal attention, and more frontal regions of the brain responsible for letter recognition and working memory. Perhaps when viewing through their amblyopic eyes, the observers were still processing the letter identity of a prior distractor when the color flash associated with the target was detected. After T1, unfocused temporal attention may have bound together erroneously the features of succeeding letters, resulting in the appearance of letters that were not actually presented. These findings highlight the role of early (monocular) visual processes in modulating the attentional blink, as well as the role of attention in amblyopic visual deficits.

  15. Paralysis of the orbicularis muscle of the eye using botulinum toxin type A in the treatment for dry eye.

    PubMed

    Serna-Ojeda, Juan Carlos; Nava-Castaneda, Angel

    2017-03-01

    To evaluate the efficacy of botulinum toxin type A injection to cause orbicularis eyelid muscle paralysis to improve dry eye signs and symptoms. A prospective, randomized, comparative eye-to-eye and interventional study was performed. Patients with dry eye symptoms and positive fluorescein corneal staining were included. Randomly one eyelid received a subcutaneous injection of botulinum toxin in the medial orbicularis muscle portion of the lower eyelid, and the other eye received placebo. The subjective evaluation was achieved with a questionnaire assessing symptoms, quality of vision and ocular comfort level. The objective evaluation included the measurement of the tear film break-up time (TBUT), Schirmer's test and corneal and conjunctival staining. Twenty patients were included with a mean age of 59.5 years. Two weeks after the botulinum toxin injection, all patients showed a decrease in the horizontal movement of the lower eyelid when blinking. The eyes in the active treatment group showed better scores compared with the sham group in four symptoms 4 weeks after the treatment. The TBUT was higher at 1 and 3 months in the active treatment group. The corneal and conjunctival staining were significantly lower in the active treatment group at 1 and 3 months, and the Schirmer's test showed better measurements in the same group at 2 weeks, 1 month and 3 months. There were no adverse events reported. The injection of botulinum toxin A in the medial part of the lower eyelid is an effective and safe procedure that temporally improves some of the signs and symptoms of patients with dry eye. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. The role of amniotic membrane extract eye drop (AMEED) in in vivo cultivation of limbal stem cells.

    PubMed

    Baradaran-Rafii, Alireza; Asl, Niloufar Shayan; Ebrahimi, Marzieh; Jabbehdari, Sayena; Bamdad, Shahram; Roshandel, Danial; Eslani, Medi; Momeni, Maryam

    2018-01-01

    Limbal stem cell transplantation (LSCT) is the definitive treatment for total limbal stem cell deficiency (LSCD). This study evaluates the anatomical and visual outcomes of a surgical technique supplemented by amniotic membrane extract eye drop (AMEED) for in vivo cultivation of limbal stem cells (LSCs). One small limbal block (2 × 1 mm) harvested from the contralateral healthy eye was transferred to the diseased eye, which had been already covered by cryopreserved amniotic membrane (N = 20). The patients were categorized into case and control groups. AMEED was administered postoperatively only for patients in the case group (N = 14). Sequential penetrating keratoplasty (PKP) was performed in 4 eyes of the case group for optical clarity. Visual acuity, epithelial healing, corneal clarity and regression of conjunctivalization/vascularization were evaluated after surgery. The corneal buttons of post-PKP eyes were evaluated for LSC markers. In the case group, the mean corrected distance visual acuity (CDVA) was 20/400 before surgery, which improved to 20/40 and 20/50 at the last follow-up in eyes with and without PKP, respectively. Epithelial defects healed in all eyes of the case group during 2 weeks after surgery. Corneal conjunctivalization/vascularization regressed dramatically in all patients of the case group 2-3 months after surgery. In PKP cases, all transplanted corneas were clear at the last follow-up. LSC markers were expressed on the surface of all trephined corneal buttons. All eyes in the control group developed persistent epithelial defect. This study suggests that amniotic membrane extract may be helpful for in vivo cultivation of limbal stem cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Plasma rich in growth factors (PRGF) eye drops stimulates scarless regeneration compared to autologous serum in the ocular surface stromal fibroblasts.

    PubMed

    Anitua, E; de la Fuente, M; Muruzabal, F; Riestra, A; Merayo-Lloves, J; Orive, G

    2015-06-01

    Autologous serum (AS) eye drops was the first blood-derived product used for the treatment of corneal pathologies but nowadays PRGF arises as a novel interesting alternative to this type of diseases. The purpose of this study was to evaluate and compare the biological outcomes of autologous serum eye drops or Plasma rich in growth factors (PRGF) eye drops on corneal stromal keratocytes (HK) and conjunctival fibroblasts (HConF). To address this, blood from healthy donors was collected and processed to obtain autologous serum (AS) eye drops and plasma rich in growth factors (PRGF) eye drops. Blood-derivates were aliquoted and stored at -80°C until use. PDGF-AB, VEGF, EGF, FGFb and TGF-β1 were quantified. The potential of PRGF and AS in promoting wound healing was evaluated by means of proliferation and migration assays in HK and HConF. Fibroblast cells were induced to myofibroblast differentiation after treatment with 2.5ng/mL of TGF-β1. The capability of PRGF and AS to prevent and inhibit TGF-β1-induced differentiation was evaluated. Results showed significant higher levels of all growth factors analyzed in PRGF eye drops compared to AS. Moreover, PRGF eye drops enhanced significantly the biological outcomes of both HK and HConF, and reduced TGF-β1-induced myofibroblast differentiation in contrast to autologous serum eye drops (AS). In summary, these results suggest that PRGF exerts enhanced biological outcomes than AS. PRGF may improve the treatment of ocular surface wound healing minimizing the scar formation compared to AS. Results obtained herein suggest that PRGF protects and reverses the myofibroblast phenotype while promotes cell proliferation and migration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Visually Impaired Drivers Who Use Bioptic Telescopes: Self-Assessed Driving Skills and Agreement With On-Road Driving Evaluation

    PubMed Central

    Owsley, Cynthia; McGwin, Gerald; Elgin, Jennifer; Wood, Joanne M.

    2014-01-01

    Purpose. To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a “backseat” evaluator. Methods. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Results. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P < 0.05). Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Conclusions. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure. PMID:24370830

  19. Visually impaired drivers who use bioptic telescopes: self-assessed driving skills and agreement with on-road driving evaluation.

    PubMed

    Owsley, Cynthia; McGwin, Gerald; Elgin, Jennifer; Wood, Joanne M

    2014-01-15

    To compare self-assessed driving habits and skills of licensed drivers with central visual loss who use bioptic telescopes to those of age-matched normally sighted drivers, and to examine the association between bioptic drivers' impressions of the quality of their driving and ratings by a "backseat" evaluator. Participants were licensed bioptic drivers (n = 23) and age-matched normally sighted drivers (n = 23). A questionnaire was administered addressing driving difficulty, space, quality, exposure, and, for bioptic drivers, whether the telescope was helpful in on-road situations. Visual acuity and contrast sensitivity were assessed. Information on ocular diagnosis, telescope characteristics, and bioptic driving experience was collected from the medical record or in interview. On-road driving performance in regular traffic conditions was rated independently by two evaluators. Like normally sighted drivers, bioptic drivers reported no or little difficulty in many driving situations (e.g., left turns, rush hour), but reported more difficulty under poor visibility conditions and in unfamiliar areas (P < 0.05). Driving exposure was reduced in bioptic drivers (driving 250 miles per week on average vs. 410 miles per week for normally sighted drivers, P = 0.02), but driving space was similar to that of normally sighted drivers (P = 0.29). All but one bioptic driver used the telescope in at least one driving task, and 56% used the telescope in three or more tasks. Bioptic drivers' judgments about the quality of their driving were very similar to backseat evaluators' ratings. Bioptic drivers show insight into the overall quality of their driving and areas in which they experience driving difficulty. They report using the bioptic telescope while driving, contrary to previous claims that it is primarily used to pass the vision screening test at licensure.

  20. Ocular injuries due to projectile impacts.

    PubMed

    Scott, W R; Lloyd, W C; Benedict, J V; Meredith, R

    2000-01-01

    An animal model has been developed using enucleated porcine eyes to evaluate ocular trauma. The eyes were pressurized to approximately 18 mmHg and mounted in a container with a 10% gelatin mixture. The corneas of sixteen pressurized eyes were impacted by a blunt metal projectile (mass of 2.6 gm, 3.5 gm or 45.5 gm) at velocities of 4.0 to 38.1 m/s. The impacted eyes were evaluated by an ophthalmologist. A numerical classification scheme was used to categorize the severity of the ocular injury. A chi-squared test indicates that the injury level is associated with the kinetic energy (KE) and not the momentum of the projectile. The enucleated eyes began to experience lens dislocations when the KE of the projectile was approximately 0.75 Nm, and retinal injuries when the KE was approximately 1.20 Nm.

  1. Ocular Injuries Due to Projectile Impacts

    PubMed Central

    (Michael) Scott, William R.; Lloyd, William C.; Benedict, James V.; Meredith, Roy

    2000-01-01

    An animal model has been developed using enucleated porcine eyes to evaluate ocular trauma. The eyes were pressurized to approximately 18mmHg and mounted in a container with a 10% gelatin mixture. The corneas of sixteen pressurized eyes were impacted by a blunt metal projectile (mass of 2.6gm, 3.5gm or 45.5gm) at velocities of 4.0 to 38.1 m/s. The impacted eyes were evaluated by an ophthalmologist. A numerical classification scheme was used to categorize the severity of the ocular injury. A chi-squared test indicates that the injury level is associated with the kinetic energy (KE) and not the momentum of the projectile. The enucleated eyes began to experience lens dislocations when the KE of the projectile was approximately 0.75Nm, and retinal injuries when the KE was approximately 1.20Nm. PMID:11558084

  2. Integrated flexible handheld probe for imaging and evaluation of iridocorneal angle

    NASA Astrophysics Data System (ADS)

    Shinoj, Vengalathunadakal K.; Murukeshan, Vadakke Matham; Baskaran, Mani; Aung, Tin

    2015-01-01

    An imaging probe is designed and developed by integrating a miniaturized charge-coupled diode camera and light-emitting diode light source, which enables evaluation of the iridocorneal region inside the eye. The efficiency of the prototype probe instrument is illustrated initially by using not only eye models, but also samples such as pig eye. The proposed methodology and developed scheme are expected to find potential application in iridocorneal angle documentation, glaucoma diagnosis, and follow-up management procedures.

  3. 21 CFR 886.1870 - Stereoscope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle deviation), evaluate binocular vision (usage of both eyes to see), and guide a patient's corrective exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the...

  4. 21 CFR 886.1870 - Stereoscope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle deviation), evaluate binocular vision (usage of both eyes to see), and guide a patient's corrective exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the...

  5. Eye-tracking for clinical decision support: A method to capture automatically what physicians are viewing in the EMR.

    PubMed

    King, Andrew J; Hochheiser, Harry; Visweswaran, Shyam; Clermont, Gilles; Cooper, Gregory F

    2017-01-01

    Eye-tracking is a valuable research tool that is used in laboratory and limited field environments. We take steps toward developing methods that enable widespread adoption of eye-tracking and its real-time application in clinical decision support. Eye-tracking will enhance awareness and enable intelligent views, more precise alerts, and other forms of decision support in the Electronic Medical Record (EMR). We evaluated a low-cost eye-tracking device and found the device's accuracy to be non-inferior to a more expensive device. We also developed and evaluated an automatic method for mapping eye-tracking data to interface elements in the EMR (e.g., a displayed laboratory test value). Mapping was 88% accurate across the six participants in our experiment. Finally, we piloted the use of the low-cost device and the automatic mapping method to label training data for a Learning EMR (LEMR) which is a system that highlights the EMR elements a physician is predicted to use.

  6. Eye-tracking for clinical decision support: A method to capture automatically what physicians are viewing in the EMR

    PubMed Central

    King, Andrew J.; Hochheiser, Harry; Visweswaran, Shyam; Clermont, Gilles; Cooper, Gregory F.

    2017-01-01

    Eye-tracking is a valuable research tool that is used in laboratory and limited field environments. We take steps toward developing methods that enable widespread adoption of eye-tracking and its real-time application in clinical decision support. Eye-tracking will enhance awareness and enable intelligent views, more precise alerts, and other forms of decision support in the Electronic Medical Record (EMR). We evaluated a low-cost eye-tracking device and found the device’s accuracy to be non-inferior to a more expensive device. We also developed and evaluated an automatic method for mapping eye-tracking data to interface elements in the EMR (e.g., a displayed laboratory test value). Mapping was 88% accurate across the six participants in our experiment. Finally, we piloted the use of the low-cost device and the automatic mapping method to label training data for a Learning EMR (LEMR) which is a system that highlights the EMR elements a physician is predicted to use. PMID:28815151

  7. Evaluating a Tablet Application and Differential Reinforcement to Increase Eye Contact in Children with Autism

    ERIC Educational Resources Information Center

    Jeffries, Tricia; Crosland, Kimberly; Miltenberger, Raymond

    2016-01-01

    We tested the effectiveness of a tablet application and differential reinforcement to increase eye contact in 3 children with autism. The application required the child to look at a picture of a person's face and identify the number displayed in the person's eyes. Eye contact was assessed immediately after training, 1 hr after training, and in a…

  8. Relationship between blood and urine alcohol concentrations in apprehended drivers who claimed consumption of alcohol after driving with and without supporting evidence.

    PubMed

    Jones, Alan Wayne; Kugelberg, Fredrik C

    2010-01-30

    For various reasons, many people suspected of driving under the influence of alcohol (DUIA) are not apprehended sitting behind the wheel, but some time after the driving. This gives them the opportunity to claim they drank alcohol after the time of driving or after they were involved in a road-traffic crash. Alleged post-offence drinking is not easy for the prosecution to disprove, which often means that the DUIA charge is dropped or the person is acquitted if the case goes to trial. The routine practice of sampling and measuring the concentration of alcohol in blood (BAC) and urine (UAC) and calculating urine/blood ratios (UAC/BAC) and the changes in UAC between two successive voids furnishes useful information to support or challenge alleged drinking after driving. We present here a retrospective case series of DUIA offenders (N=40) in half of which there was supporting evidence of an after-drink (eye witness or police reports) and in the other half no such evidence existed apart from the suspect's admission. When there was supporting evidence of an after-drink, the UAC/BAC ratio for the first void was close to or less than unity (mean 1.04, median 1.08, range 0.54-1.21) and the UAC increased by 0.21 g/L (range 0.02-0.57) between the two voids. Without any supporting evidence of post-offence drinking the mean UAC/BAC ratio was 1.46 (range 1.35-1.93) for the first void, verifying that absorption and distribution of alcohol in all body fluids and tissues was complete. In these cases, the UAC between successive voids decreased by 0.25 g/L on average (range 0.10-0.49), indicating the post-absorptive phase of the BAC curve. Long experience from investigating claims of post-offence drinking leads us to conclude that in the vast majority of cases this lacks any substance and is simply a last resort by DUIA offenders to evade justice. Unless supporting evidence exists (eye witness, police reports, etc.) of post-offence drinking the courts are encouraged to ignore this defence argument. 2009 Elsevier Ireland Ltd. All rights reserved.

  9. Effectiveness of Autologous Serum Eye Drops Combined With Punctal Plugs for the Treatment of Sjögren Syndrome-Related Dry Eye.

    PubMed

    Liu, Ying; Hirayama, Masatoshi; Cui, Xin; Connell, Samuel; Kawakita, Tetsuya; Tsubota, Kazuo

    2015-10-01

    To evaluate the efficacy and safety of autologous serum (AS) eye drops combined with punctal plugs (PPs) in patients with Sjögren syndrome (SS)-related dry eye. A retrospective clinical study was performed in patients with dry eye caused by SS. We evaluated the Schirmer test value, tear breakup time (tBUT), and fluorescein and Rose Bengal (RB) staining scores at baseline, 3 months, 6 months, 1 year, and >1 year after treatment. The dry eye indexes were also evaluated in 2 subgroups, which determined by the using of PPs, including the AS + PP group and AS only group. A total of 56 eyes of 28 patients were investigated with a mean follow-up of 42.3 ± 26.1 months. After the application of AS eye drops, the Schirmer test showed no significant changes. The tBUT (2.7 ± 1.9 seconds) was significantly improved at each time point (3.9 ± 3.1, 4.5 ± 3.1, 3.7 ± 2.5, and 5.1 ± 4.0; P < 0.01), fluorescein staining (4.3 ± 2.8) was significantly improved at each time point (2.2 ± 2.2, 1.9 ± 1.9, 1.8 ± 1.6, and 1.8 ± 1.8; P < 0.01), and RB (2.6 ± 3.0) staining was significantly improved from 6-month treatment (1.5 ± 1.9, 1.9 ± 1.9, and 1.4 ± 1.8; P < 0.05, 0.01, and 0.01, respectively). When combined with PPs, the tBUT and RB staining scores were found to be significantly improved in the AS + PP group compared with those of the AS only group. Long-term application of AS eye drops was found to be an effective and apparently safe treatment for SS dry eye. Furthermore, PPs in combination with AS eye drops were considered to have an additive effect on SS dry eye.

  10. 10 Gb/s operation of photonic crystal silicon optical modulators.

    PubMed

    Nguyen, Hong C; Sakai, Yuya; Shinkawa, Mizuki; Ishikura, Norihiro; Baba, Toshihiko

    2011-07-04

    We report the first experimental demonstration of 10 Gb/s modulation in a photonic crystal silicon optical modulator. The device consists of a 200 μm-long SiO2-clad photonic crystal waveguide, with an embedded p-n junction, incorporated into an asymmetric Mach-Zehnder interferometer. The device is integrated on a SOI chip and fabricated by CMOS-compatible processes. With the bias voltage set at 0 V, we measure a V(π)L < 0.056 V∙cm. Optical modulation is demonstrated by electrically driving the device with a 2(31) - 1 bit non-return-to-zero pseudo-random bit sequence signal. An open eye pattern is observed at bitrates of 10 Gb/s and 2 Gb/s, with and without pre-emphasis of the drive signal, respectively.

  11. Outer Retinal Assessment Using Spectral-Domain Optical Coherence Tomography in Patients With Alzheimer's and Parkinson's Disease.

    PubMed

    Uchida, Atsuro; Pillai, Jagan A; Bermel, Robert; Bonner-Jackson, Aaron; Rae-Grant, Alexander; Fernandez, Hubert; Bena, James; Jones, Stephen E; Leverenz, James B; Srivastava, Sunil K; Ehlers, Justis P

    2018-06-01

    To investigate outer retinal parameters among patients with various chronic neurodegenerative disorders by using spectral-domain coherence tomography (OCT) in a prospective cross-sectional cohort study. A total of 132 participants were enrolled following a comprehensive diagnostic evaluation with neurologic, neuropsychology, and magnetic resonance imaging volumetric evaluations. Participants were 50 years or older, either diagnosed with Alzheimer's disease (AD) dementia, amnestic mild cognitive impairment (MCI), non-AD dementia, Parkinson's disease (PD), or age- and sex-matched controls. All participants underwent a macular cube scan for both eyes by using the Cirrus 4000 HD-OCT (Zeiss, Oberkochen, Germany). The OCT image with the best quality was selected for further analysis. Outer retinal parameters including ellipsoid zone mapping and outer nuclear layer metrics were evaluated with a novel software platform. One hundred twenty-four eyes of 124 participants with AD dementia (24 eyes), amnestic MCI (22 eyes), non-AD dementia (20 eyes), PD (22 eyes), and age- and sex-matched controls (36 eyes) were included in the analysis. Eight eyes were excluded either due to the presence of macular disease or poor quality of the OCT image. The mean ages of participants were 65.9 ± 8.9 years. The outer retinal thickness measures did not show any statistical significance between the groups. However, ellipsoid zone to retinal pigment epithelium volume correlated with cognitive testing scores in all study participants. There were no identifiable differences in the outer retinal metrics across neurodegenerative disease groups and controls. The relationship between the degree of cognitive impairment and ellipsoid zone to retinal pigment epithelium volume warrants further study.

  12. Driving safety after brain damage: follow-up of twenty-two patients with matched controls.

    PubMed

    Katz, R T; Golden, R S; Butter, J; Tepper, D; Rothke, S; Holmes, J; Sahgal, V

    1990-02-01

    Driving after brain damage is a vital issue, considering the large number of patients who suffer from cerebrovascular and traumatic encephalopathy. The ability to operate a motor vehicle is an integral part of independence for most adults and so should be preserved whenever possible. The physician may estimate a patient's ability to drive safely based on his own examination, the evaluation of a neuropsychologist, and a comprehensive driving evaluation--testing, driving simulation, behind-the-wheel observation--with a driving specialist. This study sought to evaluate the ability of brain-damaged individuals to operate a motor vehicle safely at follow-up. These patients had been evaluated (by a physician, a neuropsychologist, and a driving specialist) and were judged able to operate a motor vehicle safely after their cognitive insult. Twenty-two brain-damaged patients who were evaluated at our institution were successfully followed up to five years (mean interval of 2.67 years). Patients were interviewed by telephone. Their driving safely was compared with a control group consisting of a close friend or spouse of each patient. Statistical analysis revealed no difference between patient and control groups in the type of driving, the incidence of speeding tickets, near accidents, and accidents, and the cost of vehicle damage when accidents occurred. The patient group was further divided into those who had, and those who had not experienced driving difficulties so that initial neuropsychologic testing could be compared. No significant differences were noted in any aspect of the neuropsychologic test battery. We conclude that selected brain-damaged patients who have passed a comprehensive driving assessment as outlined were as fit to drive as were their normal matched controls.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Retinal Capillary Network and Foveal Avascular Zone in Eyes with Vein Occlusion and Fellow Eyes Analyzed With Optical Coherence Tomography Angiography.

    PubMed

    Adhi, Mehreen; Filho, Marco A Bonini; Louzada, Ricardo N; Kuehlewein, Laura; de Carlo, Talisa E; Baumal, Caroline R; Witkin, Andre J; Sadda, Srinivas R; Sarraf, David; Reichel, Elias; Duker, Jay S; Waheed, Nadia K

    2016-07-01

    To evaluate the perifoveolar retinal capillary network at different depths and to quantify the foveal avascular zone (FAZ) in eyes with retinal vein occlusion (RVO) compared with their fellow eyes and healthy controls using spectral-domain optical coherence tomography angiography (SD-OCTA). We prospectively recruited 23 patients with RVO including 15 eyes with central RVO (CRVO) and 8 eyes with branch RVO (BRVO), their fellow eyes, and 8 age-matched healthy controls (8 eyes) for imaging on prototype OCTA software within RTVue-XR Avanti. The 3 × 3 mm and 6 × 6 mm en face angiograms of superficial and deep retinal capillary plexuses were segmented. Perifoveolar retinal capillary network was analyzed and FAZ was quantified. Decrease in vascular perfusion at the deep plexus was observed in all eyes with CRVO (8/8, 100%) and BRVO (6/6, 100%) without cystoid macular edema, and in 8 of 15 (53%) and 2 of 8 (25%) of the fellow eyes, respectively. Vascular tortuosity was observed in 13 of 15 (87%) CRVO and 5 of 8 (63%) BRVO eyes. Collaterals were seen in 10 of 15 (67%) CRVO and 5 of 8 (63%) BRVO eyes. Mean FAZ area was larger in eyes with RVO than their fellow eyes (1.13 ± 0.25 mm2 versus 0.58 ± 0.28 mm2; P = 0.007) and controls (1.13 ± 0.25 mm2 versus 0.30 ± 0.09 mm2; P < 0.0001), and in fellow eyes of RVO patients when compared to controls (0.58 ± 0.28 mm2 versus 0.30 ± 0.09 mm2; P = 0.01). Spectral-domain OCTA reveals abnormalities at different levels of perifoveolar retinal capillary network and is able to quantify the FAZ in RVO. Longitudinal studies may be considered to evaluate the clinical utility of OCTA in RVO and other retinal vascular diseases.

  14. The EyeHarp: A Gaze-Controlled Digital Musical Instrument

    PubMed Central

    Vamvakousis, Zacharias; Ramirez, Rafael

    2016-01-01

    We present and evaluate the EyeHarp, a new gaze-controlled Digital Musical Instrument, which aims to enable people with severe motor disabilities to learn, perform, and compose music using only their gaze as control mechanism. It consists of (1) a step-sequencer layer, which serves for constructing chords/arpeggios, and (2) a melody layer, for playing melodies and changing the chords/arpeggios. We have conducted a pilot evaluation of the EyeHarp involving 39 participants with no disabilities from both a performer and an audience perspective. In the first case, eight people with normal vision and no motor disability participated in a music-playing session in which both quantitative and qualitative data were collected. In the second case 31 people qualitatively evaluated the EyeHarp in a concert setting consisting of two parts: a solo performance part, and an ensemble (EyeHarp, two guitars, and flute) performance part. The obtained results indicate that, similarly to traditional music instruments, the proposed digital musical instrument has a steep learning curve, and allows to produce expressive performances both from the performer and audience perspective. PMID:27445885

  15. Prevalence of dry eye syndrome and Sjogren's syndrome in patients with rheumatoid arthritis.

    PubMed

    Kosrirukvongs, Panida; Ngowyutagon, Panotsom; Pusuwan, Pawana; Koolvisoot, Ajchara; Nilganuwong, Surasak

    2012-04-01

    Rheumatoid arthritis has manifestations in various organs including ophthalmic involvement. The present study evaluates prevalence of dry eye and secondary Sjogren's syndrome using salivary scintigraphy which has not been used in previous reports. To evaluate the prevalence of secondary Sjogren's syndrome in patients with rheumatoid arthritis, including clinical characteristics and dry eye, compared with non-Sjogren's syndrome. Descriptive cross sectional study Sixty-one patients with rheumatoid arthritis were recruited at Siriraj Hospital during March 2009-September 2010 and filled in the questionnaires about dry eye for Ocular Surface Disease Index (OSDI) with a history taking of associated diseases, medications, duration of symptoms of dry eyes and dry mouth. The Schirmer I test without anesthesia, tear break-up time, rose bengal staining score, severity of keratitis and salivary scintigraphy were measured and analyzed. Prevalence of secondary Sjogren's syndrome and dry eye were 22.2% (95% CI 15.4 to 30.9) and 46.7% (95% CI 38.0 to 55.6), respectively. Dry eye interpreted from OSDI, Schirmer 1 test, tear break-up time and rose bengal staining was 16.4%, 46.7%, 82% and 3.3% respectively. Fifty-two percent of patients had a history of dry eye and dry mouth with mean duration 27.4 and 29.8 months, respectively. Superficial punctate keratitis and abnormal salivary scintigraphy were found in 58.2% and 77.8%. Duration of rheumatoid arthritis, erythrocyte sedimentation rate were not correlated with secondary Sjogren's syndrome. Dry eye from OSDI with secondary Sjogren's syndrome (33.3%) compared with non-Sjogren's syndrome (9.5%) was significant difference (p = 0.008). Adjusted odds ratio for secondary Sjogren's syndrome in OSDIL score > 25 was 13.8 (95% CI 2.6 to 73.8, p = 0.002) compared to OSDI score < 25. Awareness and detection of dry eye syndrome and secondary Sjogren's syndrome in rheumatoid arthritis was crucial for evaluation of their severity and proper management.

  16. Three-dimensional vascular imaging of proliferative diabetic retinopathy by Doppler optical coherence tomography.

    PubMed

    Miura, Masahiro; Hong, Young-Joo; Yasuno, Yoshiaki; Muramatsu, Daisuke; Iwasaki, Takuya; Goto, Hiroshi

    2015-03-01

    To evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT). Prospective, nonrandomized clinical trial. Seventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions. Proliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions. Doppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Gefarnate stimulates mucin-like glycoprotein secretion in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models.

    PubMed

    Dota, Atsuyoshi; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu

    2013-01-01

    The aim of this study was to evaluate the effect of gefarnate on mucin-like glycoprotein secretion in isolated rabbit conjunctival tissue, and on corneal epithelial damage in rabbit and cat dry-eye models. Conjunctival tissue isolated from rabbits was treated with gefarnate. Mucin-like glycoprotein was detected in the culture supernatant by an enzyme-linked lectin assay. Gefarnate ointment was topically applied to eyes once daily for 7 days in the rabbit dry-eye model, in which the lacrimal glands, Harderian gland, and nictitating membrane were removed, or for 4 weeks in the cat dry-eye model, in which the lacrimal gland and nictitating membrane were removed. Corneal epithelial damage was evaluated by measurement of corneal permeability by rose bengal in the rabbit model or by fluorescein staining in the cat model. Gefarnate stimulated mucin-like glycoprotein secretion in conjunctival tissue in a dose-dependent manner. In the rabbit dry-eye model, application of gefarnate ointment to the eyes resulted in a dose-dependent decrease in rose bengal permeability in the cornea, with the effect being significant at concentrations of ≥0.3%. In the cat dry-eye model, application of gefarnate ointment resulted in a significant decrease in the corneal fluorescein staining score. These results suggest that gefarnate stimulates in vitro secretion of mucin-like glycoprotein in conjunctival tissue and ameliorates corneal epithelial damage in animal dry-eye models. Gefarnate may therefore be effective for treating dry eye.

  18. Asleep at the automated wheel-Sleepiness and fatigue during highly automated driving.

    PubMed

    Vogelpohl, Tobias; Kühn, Matthias; Hummel, Thomas; Vollrath, Mark

    2018-03-20

    Due to the lack of active involvement in the driving situation and due to monotonous driving environments drivers with automation may be prone to become fatigued faster than manual drivers (e.g. Schömig et al., 2015). However, little is known about the progression of fatigue during automated driving and its effects on the ability to take back manual control after a take-over request. In this driving simulator study with Nö=ö60 drivers we used a three factorial 2ö×ö2ö×ö12 mixed design to analyze the progression (12ö×ö5ömin; within subjects) of driver fatigue in drivers with automation compared to manual drivers (between subjects). Driver fatigue was induced as either mainly sleep related or mainly task related fatigue (between subjects). Additionally, we investigated the drivers' reactions to a take-over request in a critical driving scenario to gain insights into the ability of fatigued drivers to regain manual control and situation awareness after automated driving. Drivers in the automated driving condition exhibited facial indicators of fatigue after 15 to 35ömin of driving. Manual drivers only showed similar indicators of fatigue if they suffered from a lack of sleep and then only after a longer period of driving (approx. 40ömin). Several drivers in the automated condition closed their eyes for extended periods of time. In the driving with automation condition mean automation deactivation times after a take-over request were slower for a certain percentage (about 30%) of the drivers with a lack of sleep (Mö=ö3.2; SDö=ö2.1ös) compared to the reaction times after a long drive (Mö=ö2.4; SDö=ö0.9ös). Drivers with automation also took longer than manual drivers to first glance at the speed display after a take-over request and were more likely to stay behind a braking lead vehicle instead of overtaking it. Drivers are unable to stay alert during extended periods of automated driving without non-driving related tasks. Fatigued drivers could pose a serious hazard in complex take-over situations where situation awareness is required to prepare for threats. Driver fatigue monitoring or controllable distraction through non-driving tasks could be necessary to ensure alertness and availability during highly automated driving. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. The isolated chicken eye test as a suitable in vitro method for determining the eye irritation potential of household cleaning products.

    PubMed

    Schutte, K; Prinsen, M K; McNamee, P M; Roggeband, R

    2009-08-01

    Eye irritation is an important endpoint in the safety evaluation of consumer products and their ingredients. Several in vitro methods have been developed and are used by different industry sectors to assess eye irritation. One such in vitro method in use for some time already is the isolated chicken eye test (ICE). This investigation focuses on assessing the ICE as a method to determine the eye irritation potential of household cleaning products, both for product safety assurance prior to marketing and for classification and labeling decisions. The ICE involves a single application of test substances onto the cornea of isolated chicken eyes. Endpoints are corneal swelling, corneal opacity and fluorescein retention. The ICE results were compared to historic LVET data in this study due to availability of such in vivo data and the ability to correlate LVET to human experience data on the outcome of accidental exposures to household cleaning products in general. The results of this study indicate that the ICE test is a useful in vitro method for evaluating the eye irritation/corrosion potential and establishing classification and labeling for household cleaning products. For new product formulations, it is best used as part of a weight-of-evidence approach and benchmarked against data from comparable formulations with known eye irritation/corrosion profiles and market experience.

  20. Indocyanine green angiography in posterior uveitis

    PubMed Central

    Agrawal, Rupesh V; Biswas, Jyotirmay; Gunasekaran, Dinesh

    2013-01-01

    Literature review for indocyanine green angiography and evaluate the role of indocyanine green angiogram (ICGA) in patients with posterior uveitis seen at a tertiary referral eye care centre. Detailed review of the literature on ICGA was performed. Retrospective review of medical records of patients with posterior uveitis and dual fundus and ICGA was done after institutional board approval. Eighteen patients (26 eyes) had serpiginous choroiditis out of which 12 patients had active choroiditis and six patients had healed choroiditis, six patients (12 eyes) had ampiginous choroiditis, six patients (12 eyes) had acute multifocal posterior placoid pigment epitheliopathy, eight patients (10 eyes) had multifocal choroiditis, four patients (eight eyes) had presumed ocular histoplasmosis syndrome, four patients (eight eyes) had presumed tuberculous choroiditis, two patients (four eyes) had multiple evanescent white dot syndrome and two patients (four eyes) had Vogt Koyanagi Harada (VKH) syndrome. The most characteristic feature noted on ICGA was the presence of different patterns of hypofluorescent dark spots, which were present at different stages of the angiogram. ICGA provides the clinician with a powerful adjunctive tool in choroidal inflammatory disorders. It is not meant to replace already proven modalities such as the fluorescein angiography, but it can provide additional information that is useful in establishing a more definitive diagnosis in inflammatory chorioretinal diseases associated with multiple spots. It still needs to be determined if ICGA can prove to be a follow up parameter to evaluate disease progression. PMID:23685486

  1. On the feasibility of utilizing active personal dosimeters worn on the chest to estimate occupational eye lens dose in x-ray angiography.

    PubMed

    Omar, Artur; Marteinsdottir, Maria; Kadesjö, Nils; Fransson, Annette

    2015-06-01

    The International Commission on Radiological Protection (ICRP) has recommended that the occupational dose limit to the eye lens be substantially reduced. To ensure compliance with these recommendations, monitoring of the occupational eye lens dose is essential in certain hospital work environments. For assessment of the eye lens dose it is recommended to use a supplementary dosimeter placed at a position adjacent to the eye(s). Wearing a dosimeter at eye level can, however, be impractical and distributing and managing additional dosimeters over long periods of time is cumbersome and costly for large clinical sites. An attractive alternative is to utilize active personal dosimeters (APDs), which are routinely used by clinical staff for real-time monitoring of the personal dose equivalent rate (H(p)(10)). In this work, a formalism for the determination of eye lens dose from the response of such APD's worn on the chest is proposed and evaluated. The evaluation is based on both phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. The main results show that the eye lens dose to the primary operator and to the assisting clinical staff can be conservatively estimated from the APD response as D(eye)(conductor) = 2.0 APD chest and D(eye)(assisting) = 1.0 APD chest, respectively. However, care should be exercised for particularly short assisting staff and if radiation protection shields are misused. These concerns can be greatly mitigated if the clinical staff are provided with adequate radiation protection training.

  2. Peak skin and eye lens radiation dose from brain perfusion CT based on Monte Carlo simulation.

    PubMed

    Zhang, Di; Cagnon, Chris H; Villablanca, J Pablo; McCollough, Cynthia H; Cody, Dianna D; Stevens, Donna M; Zankl, Maria; Demarco, John J; Turner, Adam C; Khatonabadi, Maryam; McNitt-Gray, Michael F

    2012-02-01

    The purpose of our study was to accurately estimate the radiation dose to skin and the eye lens from clinical CT brain perfusion studies, investigate how well scanner output (expressed as volume CT dose index [CTDI(vol)]) matches these estimated doses, and investigate the efficacy of eye lens dose reduction techniques. Peak skin dose and eye lens dose were estimated using Monte Carlo simulation methods on a voxelized patient model and 64-MDCT scanners from four major manufacturers. A range of clinical protocols was evaluated. CTDI(vol) for each scanner was obtained from the scanner console. Dose reduction to the eye lens was evaluated for various gantry tilt angles as well as scan locations. Peak skin dose and eye lens dose ranged from 81 mGy to 348 mGy, depending on the scanner and protocol used. Peak skin dose and eye lens dose were observed to be 66-79% and 59-63%, respectively, of the CTDI(vol) values reported by the scanners. The eye lens dose was significantly reduced when the eye lenses were not directly irradiated. CTDI(vol) should not be interpreted as patient dose; this study has shown it to overestimate dose to the skin or eye lens. These results may be used to provide more accurate estimates of actual dose to ensure that protocols are operated safely below thresholds. Tilting the gantry or moving the scanning region further away from the eyes are effective for reducing lens dose in clinical practice. These actions should be considered when they are consistent with the clinical task and patient anatomy.

  3. Assessment of Eye Fatigue Caused by 3D Displays Based on Multimodal Measurements

    PubMed Central

    Bang, Jae Won; Heo, Hwan; Choi, Jong-Suk; Park, Kang Ryoung

    2014-01-01

    With the development of 3D displays, user's eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs), biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR), facial temperature (FT), and a subjective evaluation (SE) score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel) camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG) is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively. PMID:25192315

  4. The Relation of Ocular Surface Irregularity and Visual Disturbance in Early Stage Acanthamoeba Keratitis.

    PubMed

    Matsumoto, Yukihiro; Kodama, Asako; Goto, Eiki; Kawakita, Tetsuya; Dogru, Murat; Tsubota, Kazuo

    2017-01-01

    To evaluate the relation between ocular surface irregularity and visual disturbance in early stage Acanthamoeba keratitis (AK). Fifteen patients with culture-proven AK underwent routine ophthalmic examinations, including best-corrected visual acuity (BCVA) measurement, slitlamp biomicroscope examination, and corneal fluorescein dye staining test, in both the eyes. We also evaluated the corneal sensitivity with Cochet-Bonnet esthesiometer, tear functions by Schirmer's test, and ocular surface irregularity by corneal topography and compared the results with the contralateral healthy eyes in this study. The mean logarithm of the minimum angle of resolution BCVA (0.71±0.77) was significantly lower in the eyes with AK (P=0.002). Epithelial disorders were present in all eyes, and radial keratoneuritis in 14 eyes (93.3%). The mean corneal sensitivity (39.3±24.1 mm) was significantly lower in eyes with AK compared with the healthy eyes (P=0.005). The mean Schirmer's test value (22.5±12.0 mm) in eyes with AK was significantly higher compared with the healthy eyes (P=0.01). The ocular surface irregularity indices (the surface regularity index, 2.47±0.42; the surface asymmetry index, 3.24±1.31) were significantly higher in eyes with AK compared with contralateral healthy eyes (P<0.0001 and P<0.0001, respectively). The ocular surface disease in AK is associated with decrease in corneal sensitivity and increase in Schirmer's test value and ocular surface irregularity indices. The visual disturbance in AK may owe not only to corneal haze but also to ocular surface irregularity.

  5. Drug Recognition Expert (DRE) examination characteristics of cannabis impairment.

    PubMed

    Hartman, Rebecca L; Richman, Jack E; Hayes, Charles E; Huestis, Marilyn A

    2016-07-01

    The Drug Evaluation and Classification Program (DECP) is commonly utilized in driving under the influence (DUI) cases to help determine category(ies) of impairing drug(s) present in drivers. Cannabis, one of the categories, is associated with approximately doubled crash risk. Our objective was to determine the most reliable DECP metrics for identifying cannabis-driving impairment. We evaluated 302 toxicologically-confirmed (blood Δ(9)-tetrahydrocannabinol [THC] ≥1μg/L) cannabis-only DECP cases, wherein examiners successfully identified cannabis, compared to normative data (302 non-impaired individuals). Physiological measures, pupil size/light reaction, and performance on psychophysical tests (one leg stand [OLS], walk and turn [WAT], finger to nose [FTN], Modified Romberg Balance [MRB]) were included. Cases significantly differed from controls (p<0.05) in pulse (increased), systolic blood pressure (elevated), and pupil size (dilated). Blood collection time after arrest significantly decreased THC concentrations; no significant differences were detected between cases with blood THC <5μg/L versus ≥5μg/L. The FTN best predicted cannabis impairment (sensitivity, specificity, positive/negative predictive value, and efficiency ≥87.1%) utilizing ≥3 misses as the deciding criterion; MRB eyelid tremors produced ≥86.1% for all diagnostic characteristics. Other strong indicators included OLS sway, ≥2 WAT clues, and pupil rebound dilation. Requiring ≥2/4 of: ≥3 FTN misses, MRB eyelid tremors, ≥2 OLS clues, and/or ≥2 WAT clues produced the best results (all characteristics ≥96.7%). Blood specimens should be collected as early as possible. The frequently-debated 5μg/L blood THC per se cutoff showed limited relevance. Combined observations on psychophysical and eye exams produced the best cannabis-impairment indicators. Published by Elsevier Ltd.

  6. Limitations of an ocular surface inflammatory biomarker in impression cytology specimens.

    PubMed

    Yafawi, Rolla; Ko, Mira; Sace, Frederick P; John-Baptiste, Annette

    2013-03-01

    A number of ocular conditions, such as dry eye, are associated with inflammation on the surface of the eye leading to irritation and ocular pain. Many drugs such as chemotherapeutics, beta blockers, angiotensin-converting enzymes and so forth also cause dry eye but currently there are no validated ocular surface biomarkers available. We evaluated sample stability, assay sensitivity, reproducibility and overall performance of impression cytology (IC) utilizing the cellular surface biomarker human leukocyte antigen DR-1 (HLA-DR) as an ocular surface inflammatory biomarker by flow cytometry in a fit-for-purpose validation study. Additionally, subjects classified as normal or having various degrees of dry eye were evaluated to determine if HLA-DR could demonstrate a clear separation between normal and dry eye samples. The assay demonstrated high dynamic range detecting a broad range of fluorescent intensities in healthy donors. Additionally, inter, intra and stability assay results demonstrated strong concordance and low variability. Overall CV% for both assays were less than 25% for all measured parameters. However, high variability was observed for donor samples assayed beyond day 10 post IC sample collection (4.2-110.8 CV%). HLA-DR expression demonstrated a progressive increase in patients with mild to severe levels of dry eye disease providing sufficient evidence it is sensitive enough to monitor inflammatory effects of dry eye when coupled with additional biomarkers and/or methodologies such as cytokine analysis or ICAM-1. This biomarker can be used to monitor ocular surface disorders in patients and to evaluate potential treatment options during drug development. Although our results demonstrate this methodology is reproducible for routine evaluation, limitations around sample integrity exist. The ocular cell surface inflammatory biomarker, HLA-DR coupled with impression cytology is a simple non-invasive robust, specific and reproducible assay that can be utilized to measure inflammatory infiltrates on the surface of the eye in IC samples less than 10-days old.

  7. 49 CFR Appendix C to Part 240 - Procedures for Obtaining and Evaluating Motor Vehicle Driving Record Data

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Evaluating Motor Vehicle Driving Record Data The purpose of this appendix is to outline the procedures... Vehicle Driving Record Data C Appendix C to Part 240 Transportation Other Regulations Relating to... that railroads consider the motor vehicle driving record of each person prior to issuing him or her...

  8. The Bull's-Eye Values Survey: A Psychometric Evaluation

    ERIC Educational Resources Information Center

    Lundgren, Tobias; Luoma, Jason B.; Dahl, JoAnne; Strosahl, Kirk; Melin, Lennart

    2012-01-01

    Two studies were conducted to develop and evaluate an instrument intended to identify and measure personal values, values attainment, and persistence in the face of barriers. Study 1 describes a content validity approach to the construction and preliminary validation of the Bull's Eye Values Survey (BEVS), using a sample of institutionalized…

  9. Needed: Instruments as Good as Our Eyes

    ERIC Educational Resources Information Center

    Brickell, Henry M.

    2011-01-01

    Evaluators use their eyes to see what is there, whether it is intended or not. But they use their test instruments to measure what is intended, whether it is there or not. Evaluators have been broadening their repertoire of instruments for years: curriculum-embedded tests, observer checklists, audiotape recorders, videotape recorders, unobtrusive…

  10. The Cost of Being Watched: Stroop Interference Increases under Concomitant Eye Contact

    ERIC Educational Resources Information Center

    Conty, Laurence; Gimmig, David; Belletier, Clement; George, Nathalie; Huguet, Pascal

    2010-01-01

    Current models in social neuroscience advance that eye contact may automatically recruit cognitive resources. Here, we directly tested this hypothesis by evaluating the distracting strength of eye contact on concurrent visual processing in the well-known Stroop's paradigm. As expected, participants showed stronger Stroop interference under…

  11. An eye on reactor and computer control

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schryver, J.; Knee, B.

    1992-01-01

    At ORNL computer software has been developed to make possible an improved eye-gaze measurement technology. Such an inovation could be the basis for advanced eye-gaze systems that may have applications in reactor control, software development, cognitive engineering, evaluation of displays, prediction of mental workloads, and military target recognition.

  12. Development of a novel disposable lid speculum with a drape.

    PubMed

    Urano, Toru; Kasaoka, Masataka; Yamakawa, Ryoji; Yukihikotamai; Nakamura, Shoichiro

    2013-01-01

    To evaluate the clinical use of a newly-developed disposable lid speculum with a drape. LiDrape® is a cylindrical device that consists of two flexible rings of polyacetal resin with a transparent elastic silicone sheet attached to the rings. The novel device holds the eyelids between the rings, and a hole in the center of the device provides a surgical field. We used the novel device in cataract surgery (75 eyes), glaucoma surgery (eleven eyes), vitrectomy (ten eyes), and intravitreal injection (six eyes) and evaluated its clinical efficacy. The LiDrape was easy to attach and detach. The novel device was not detached from the eye during surgery. No eyelashes or secretions from the meibomian glands were seen in the surgical field, and the drape provided a sufficient surgical field. The LiDrape functions as a lid speculum as well as a drape. Our results showed that the novel device is useful for ocular surgeries.

  13. Bilateral Glaucomatous Optic Neuropathy Caused by Eye Rubbing.

    PubMed

    Savastano, Alfonso; Savastano, Maria Cristina; Carlomusto, Laura; Savastano, Silvio

    2015-01-01

    In this report, we describe a particular condition of a 52-year-old man who showed advanced bilateral glaucomatous-like optic disc damage, even though the intraocular pressure resulted normal during all examinations performed. Visual field test, steady-state pattern electroretinogram, retinal nerve fiber layer and retinal tomographic evaluations were performed to evaluate the optic disc damage. Over a 4-year observational period, his visual acuity decreased to 12/20 in the right eye and counting fingers in the left eye. Visual fields were severely compromised, and intraocular pressure values were not superior to 14 mm Hg during routine examinations. An accurate anamnesis and the suspicion of this disease represent a crucial aspect to establish the correct diagnosis. In fact, our patient strongly rubbed his eyes for more than 10 h per day. Recurrent and continuous eye rubbing can induce progressive optic neuropathy, causing severe visual field damage similar to the pathology of advanced glaucoma.

  14. Biometric recognition via fixation density maps

    NASA Astrophysics Data System (ADS)

    Rigas, Ioannis; Komogortsev, Oleg V.

    2014-05-01

    This work introduces and evaluates a novel eye movement-driven biometric approach that employs eye fixation density maps for person identification. The proposed feature offers a dynamic representation of the biometric identity, storing rich information regarding the behavioral and physical eye movement characteristics of the individuals. The innate ability of fixation density maps to capture the spatial layout of the eye movements in conjunction with their probabilistic nature makes them a particularly suitable option as an eye movement biometrical trait in cases when free-viewing stimuli is presented. In order to demonstrate the effectiveness of the proposed approach, the method is evaluated on three different datasets containing a wide gamut of stimuli types, such as static images, video and text segments. The obtained results indicate a minimum EER (Equal Error Rate) of 18.3 %, revealing the perspectives on the utilization of fixation density maps as an enhancing biometrical cue during identification scenarios in dynamic visual environments.

  15. Eye Gaze during Observation of Static Faces in Deaf People

    PubMed Central

    Watanabe, Katsumi; Matsuda, Tetsuya; Nishioka, Tomoyuki; Namatame, Miki

    2011-01-01

    Knowing where people look when viewing faces provides an objective measure into the part of information entering the visual system as well as into the cognitive strategy involved in facial perception. In the present study, we recorded the eye movements of 20 congenitally deaf (10 male and 10 female) and 23 (11 male and 12 female) normal-hearing Japanese participants while they evaluated the emotional valence of static face stimuli. While no difference was found in the evaluation scores, the eye movements during facial observations differed among participant groups. The deaf group looked at the eyes more frequently and for longer duration than the nose whereas the hearing group focused on the nose (or the central region of face) more than the eyes. These results suggest that the strategy employed to extract visual information when viewing static faces may differ between deaf and hearing people. PMID:21359223

  16. Ex vivo evaluation of Tono-Pen and pneumotonometry in cat eyes.

    PubMed

    Stoiber, Josef; Fernandez, Viviana; Lamar, Peggy D; Hitzl, Wolfgang; Fantes, Francisco; Parel, Jean-Marie

    2006-01-01

    To evaluate the validity and intraobserver reliability of intraocular pressure (IOP) measurements with both pneumotonometry and the Tono-Pen in a closed ex vivo system in cat eyes. IOP was increased step by step in 5 enucleated cat eyes, while taking IOP measurements with the Tono-Pen and pneumotonometry. The outcomes were compared to readings of a digital manometer simultaneously measuring the actual pressure in the anterior chamber. Pneumotonometry overestimated IOP below 15 mm Hg and underestimated pressures above 20 mm Hg. Tono-Pen tonometry considerably underestimated IOP over the whole spectrum in all of the eyes tested. The pneumotonometer was identified as the more valid and reliable instrument for cat eyes. Both tonometers are clinically useful tools to assess IOP for glaucoma studies using a cat animal model. However, one has to consider underestimation of IOP in the upper ranges. A correction formula can be used to calculate the actual IOP.

  17. Feed Forward Programming of Car Drivers’ Eye Movement Behavior. A System Theoretical Approach. Volume 1

    DTIC Science & Technology

    1980-02-01

    Standardization February 1980 13. NUMBER OF PAGES Group ( UK ), Box 65, FPO New York 09510 216 14. MONITORING AGENCY NAME A ADDRESS(I differmt bar...with lateral information input, s they- xate on the road’s lines frequently. Beginners, as driving tiea - chers report, have great difficulties in...perceptual system. Boston, Houghton Mifflin Co., 1966. GIBSON, J.J.: Principles of perceptual learning and develop- ment. New Jersey , Prentice Hall Inc

  18. The 14th Annual Conference on Manual Control. [digital simulation of human operator dynamics

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Human operator dynamics during actual manual control or while monitoring the automatic control systems involved in air-to-air tracking, automobile driving, the operator of undersea vehicles, and remote handling are examined. Optimal control models and the use of mathematical theory in representing man behavior in complex man machine system tasks are discussed with emphasis on eye/head tracking and scanning; perception and attention allocation; decision making; and motion simulation and effects.

  19. Ventilatory Responses to Hypercapnia during Wakefulness and Sleep in Obese Adolescents With and Without Obstructive Sleep Apnea Syndrome

    PubMed Central

    Yuan, Haibo; Pinto, Swaroop J.; Huang, Jingtao; McDonough, Joseph M.; Ward, Michelle B.; Lee, Yin N.; Bradford, Ruth M.; Gallagher, Paul R.; Shults, Justine; Konstantinopoulou, Sophia; Samuel, John M.; Katz, Eliot S.; Hua, Shucheng; Tapia, Ignacio E.; Marcus, Carole L.

    2012-01-01

    Study Objectives: Abnormal ventilatory drive may contribute to the pathophysiology of the childhood obstructive sleep apnea syndrome (OSAS). Concomitant with the obesity epidemic, more adolescents are developing OSAS. However, few studies have specifically evaluated the obese adolescent group. The authors hypothesized that obese adolescents with OSAS would have a blunted hypercapnic ventilatory response (HCVR) while awake and blunted ventilatory responses to carbon dioxide (CO2) during sleep compared with obese and lean adolescents without OSAS. Design: CVR was measured during wakefulness. During nonrapid eye movement (NREM) and rapid eye movement (REM) sleep, respiratory parameters and genioglossal electromyogram were measured during CO2 administration in comparison with room air in obese adolescents with OSAS, obese control study participants, and lean control study participants. Setting: Sleep laboratory. Participants: Twenty-eight obese patients with OSAS, 21 obese control study participants, and 37 lean control study participants. Results: The obese OSAS and obese control groups had a higher HCVR compared with the lean control group during wakefulness. During both sleep states, all 3 groups had a response to CO2; however, the obese OSAS group had lower percentage changes in minute ventilation, inspiratory flow, inspiratory time, and tidal volume compared with the 2 control groups. There were no significance differences in genioglossal activity between groups. Conclusions: HCVR during wakefulness is increased in obese adolescents. Obese adolescents with OSAS have blunted ventilatory responses to CO2 during sleep and do not have a compensatory prolongation of inspiratory time, despite having normal CO2 responsivity during wakefulness. Central drive may play a greater role than upper airway neuromotor tone in adapting to hypercapnia. Citation: Yuan H; Pinto SJ; Huang J; McDonough JM; Ward MB; Lee YN; Bradford RM; Gallagher PR; Shults J; Konstantinopoulou S; Samuel JM; Katz ES; Hua S; Tapia IE; Marcus CL. Ventilatory responses to hypercapnia during wakefulness and sleep in obese adolescents with and without obstructive sleep apnea syndrome. SLEEP 2012;35(9):1257–1267. PMID:22942504

  20. Glancing and Stopping Behavior of Motorcyclists and Car Drivers at Intersections

    PubMed Central

    Muttart, Jeffrey W.; Peck, Louis R.; Guderian, Steve; Bartlett, Wade; Ton, Lisa P.; Kauderer, Chris; Fisher, Donald L.; Manning, Joseph E.

    2012-01-01

    For the past decade, motorcycle fatalities have risen while other motor vehicle fatalities have declined. Many motorcycle fatalities occurred within intersections after a driver failed to see a motorcyclist. However, little is known about the behavior of motorcyclists when they negotiate an intersection. A study was undertaken to compare the behavior at intersections of an experienced group of motorcyclists when they were operating a motorcycle with their behavior when they were driving a car. Each participant navigated a course through low-volume, open roads. Participants wore eye-tracking equipment to record eye-glance information, and the motorcycle and car were instrumented with an onboard accelerometer and Global Positioning System apparatus. Results showed that participants were more likely to make last glances toward the direction of the most threatening traffic before they made a turn when they were driving a car than when they were riding a motorcycle. In addition, motorcyclists were less likely to come to a complete stop at a stop sign than car drivers. These results suggested that motorcyclists were exposing themselves to unnecessary risk. Specifically, motorcyclists frequently failed to make proper glances and practice optimal riding techniques. The behavior of the motorcyclists was compared with the current Motorcycle Safety Foundation curriculum. The results suggested that threat-response and delayed-apex techniques should be added to the training curriculum. PMID:23112436

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