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Sample records for eyes detectrors based

  1. Individual eye model based on wavefront aberration

    NASA Astrophysics Data System (ADS)

    Guo, Huanqing; Wang, Zhaoqi; Zhao, Qiuling; Quan, Wei; Wang, Yan

    2005-03-01

    Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore, the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There are four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high-order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software-ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.

  2. OPTICAL EYE MODEL: Human eye aberrations: 2. Development of a dynamic model of the human eye based on measurements

    NASA Astrophysics Data System (ADS)

    Galetskii, S. O.; Cherezova, T. Yu; Kudryashov, A. V.

    2008-11-01

    A human eye model based on a flexible semipassive bimorph mirror is proposed and experimentally realised. The model can be used for the real-time reproduction of human eye aberrations and their fluctuations. The accuracy of the reproduction of individual Zernike polynomials and of total eye aberrations of inspected patients is discussed.

  3. Segmentation method of eye region based on fuzzy logic system for classifying open and closed eyes

    NASA Astrophysics Data System (ADS)

    Kim, Ki Wan; Lee, Won Oh; Kim, Yeong Gon; Hong, Hyung Gil; Lee, Eui Chul; Park, Kang Ryoung

    2015-03-01

    The classification of eye openness and closure has been researched in various fields, e.g., driver drowsiness detection, physiological status analysis, and eye fatigue measurement. For a classification with high accuracy, accurate segmentation of the eye region is required. Most previous research used the segmentation method by image binarization on the basis that the eyeball is darker than skin, but the performance of this approach is frequently affected by thick eyelashes or shadows around the eye. Thus, we propose a fuzzy-based method for classifying eye openness and closure. First, the proposed method uses I and K color information from the HSI and CMYK color spaces, respectively, for eye segmentation. Second, the eye region is binarized using the fuzzy logic system based on I and K inputs, which is less affected by eyelashes and shadows around the eye. The combined image of I and K pixels is obtained through the fuzzy logic system. Third, in order to reflect the effect by all the inference values on calculating the output score of the fuzzy system, we use the revised weighted average method, where all the rectangular regions by all the inference values are considered for calculating the output score. Fourth, the classification of eye openness or closure is successfully made by the proposed fuzzy-based method with eye images of low resolution which are captured in the environment of people watching TV at a distance. By using the fuzzy logic system, our method does not require the additional procedure of training irrespective of the chosen database. Experimental results with two databases of eye images show that our method is superior to previous approaches.

  4. The construction of individual eye model based on eye's wavefront aberration measurement

    NASA Astrophysics Data System (ADS)

    Wang, Zhao-Qi; Guo, Huan-Qing

    2005-08-01

    Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There were four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software -ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.

  5. Eye movement identification based on accumulated time feature

    NASA Astrophysics Data System (ADS)

    Guo, Baobao; Wu, Qiang; Sun, Jiande; Yan, Hua

    2017-06-01

    Eye movement is a new kind of feature for biometrical recognition, it has many advantages compared with other features such as fingerprint, face, and iris. It is not only a sort of static characteristics, but also a combination of brain activity and muscle behavior, which makes it effective to prevent spoofing attack. In addition, eye movements can be incorporated with faces, iris and other features recorded from the face region into multimode systems. In this paper, we do an exploring study on eye movement identification based on the eye movement datasets provided by Komogortsev et al. in 2011 with different classification methods. The time of saccade and fixation are extracted from the eye movement data as the eye movement features. Furthermore, the performance analysis was conducted on different classification methods such as the BP, RBF, ELMAN and SVM in order to provide a reference to the future research in this field.

  6. Human eye haptics-based multimedia.

    PubMed

    Velandia, David; Uribe-Quevedo, Alvaro; Perez-Gutierrez, Byron

    2014-01-01

    Immersive and interactive multimedia applications offer complementary study tools in anatomy as users can explore 3D models while obtaining information about the organ, tissue or part being explored. Haptics increases the sense of interaction with virtual objects improving user experience in a more realistic manner. Common eye studying tools are books, illustrations, assembly models, and more recently these are being complemented with mobile apps whose 3D capabilities, computing power and customers are increasing. The goal of this project is to develop a complementary eye anatomy and pathology study tool using deformable models within a multimedia application, offering the students the opportunity for exploring the eye from up close and within with relevant information. Validation of the tool provided feedback on the potential of the development, along with suggestions on improving haptic feedback and navigation.

  7. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    SciTech Connect

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M.

    2014-02-15

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with{sup 125}I, {sup 103}Pd, or {sup 131}Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model

  8. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom.

    PubMed

    Lesperance, Marielle; Inglis-Whalen, M; Thomson, R M

    2014-02-01

    To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with(125)I, (103)Pd, or (131)Cs seeds, and to investigate doses to ocular structures. An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20-30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%-10% and 13%-14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%-17% and 29%-34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16%. In the full eye model

  9. A low cost human computer interface based on eye tracking.

    PubMed

    Hiley, Jonathan B; Redekopp, Andrew H; Fazel-Rezai, Reza

    2006-01-01

    This paper describes the implementation of a human computer interface based on eye tracking. Current commercially available systems exist, but have limited use due mainly to their large cost. The system described in this paper was designed to be a low cost and unobtrusive. The technique was video-oculography assisted by corneal reflections. An off-the shelf CCD webcam was used to capture images. The images were analyzed in software to extract key features of the eye. The users gaze point was then calculated based on the relative position of these features. The system is capable of calculating eye-gaze in real-time to provide a responsive interaction. A throughput of eight gaze points per second was achieved. The accuracy of the fixations based on the calculated eye-gazes were within 1 cm of the on-screen gaze location. By developing a low-cost system, this technology is made accessible to a wider range of applications.

  10. A self-calibrating, camera-based eye tracker for the recording of rodent eye movements.

    PubMed

    Zoccolan, Davide; Graham, Brett J; Cox, David D

    2010-01-01

    Much of neurophysiology and vision science relies on careful measurement of a human or animal subject's gaze direction. Video-based eye trackers have emerged as an especially popular option for gaze tracking, because they are easy to use and are completely non-invasive. However, video eye trackers typically require a calibration procedure in which the subject must look at a series of points at known gaze angles. While it is possible to rely on innate orienting behaviors for calibration in some non-human species, other species, such as rodents, do not reliably saccade to visual targets, making this form of calibration impossible. To overcome this problem, we developed a fully automated infrared video eye-tracking system that is able to quickly and accurately calibrate itself without requiring co-operation from the subject. This technique relies on the optical geometry of the cornea and uses computer-controlled motorized stages to rapidly estimate the geometry of the eye relative to the camera. The accuracy and precision of our system was carefully measured using an artificial eye, and its capability to monitor the gaze of rodents was verified by tracking spontaneous saccades and evoked oculomotor reflexes in head-fixed rats (in both cases, we obtained measurements that are consistent with those found in the literature). Overall, given its fully automated nature and its intrinsic robustness against operator errors, we believe that our eye-tracking system enhances the utility of existing approaches to gaze-tracking in rodents and represents a valid tool for rodent vision studies.

  11. A Self-Calibrating, Camera-Based Eye Tracker for the Recording of Rodent Eye Movements

    PubMed Central

    Zoccolan, Davide; Graham, Brett J.; Cox, David D.

    2010-01-01

    Much of neurophysiology and vision science relies on careful measurement of a human or animal subject's gaze direction. Video-based eye trackers have emerged as an especially popular option for gaze tracking, because they are easy to use and are completely non-invasive. However, video eye trackers typically require a calibration procedure in which the subject must look at a series of points at known gaze angles. While it is possible to rely on innate orienting behaviors for calibration in some non-human species, other species, such as rodents, do not reliably saccade to visual targets, making this form of calibration impossible. To overcome this problem, we developed a fully automated infrared video eye-tracking system that is able to quickly and accurately calibrate itself without requiring co-operation from the subject. This technique relies on the optical geometry of the cornea and uses computer-controlled motorized stages to rapidly estimate the geometry of the eye relative to the camera. The accuracy and precision of our system was carefully measured using an artificial eye, and its capability to monitor the gaze of rodents was verified by tracking spontaneous saccades and evoked oculomotor reflexes in head-fixed rats (in both cases, we obtained measurements that are consistent with those found in the literature). Overall, given its fully automated nature and its intrinsic robustness against operator errors, we believe that our eye-tracking system enhances the utility of existing approaches to gaze-tracking in rodents and represents a valid tool for rodent vision studies. PMID:21152259

  12. Directional eye fixation sensor using birefringence-based foveal detection

    NASA Astrophysics Data System (ADS)

    Gramatikov, Boris I.; Zalloum, Othman H. Y.; Wu, Yi Kai; Hunter, David G.; Guyton, David L.

    2007-04-01

    We recently developed and reported an eye fixation monitor that detects the fovea by its radial orientation of birefringent nerve fibers. The instrument used a four-quadrant photodetector and a normalized difference function to check for a best match between the detector quadrants and the arms of the bow-tie pattern of polarization states surrounding the fovea. This function had a maximum during central fixation but could not tell where the subject was looking relative to the center. We propose a linear transformation to obtain horizontal and vertical eye position coordinates from the four photodetector signals, followed by correction based on a priori calibration information. The method was verified on both a computer model and on human eyes. The major advantage of this new eye-tracking method is that it uses true information coming from the fovea, rather than reflections from other structures, to identify the direction of foveal gaze.

  13. Impact of dry eye on reading in a population-based sample of the elderly: the Salisbury Eye Evaluation.

    PubMed

    van Landingham, Suzanne W; West, Sheila K; Akpek, Esen K; Muñoz, Beatriz; Ramulu, Pradeep Y

    2014-05-01

    People with dry eye often complain of difficulty reading, but this perceived deficit has not been appropriately quantified. The purpose of this study is to determine if dry eye is associated with measurable reading deficits. A cross-sectional study of 1981 participants in the Salisbury Eye Evaluation, a population-based study of the elderly. Dry eye symptoms were identified by questionnaire and clinically significant dry eye was defined as the presence of dry eye symptoms and positive Schirmer testing or ocular surface staining in either eye. Spoken reading speed was measured using short text passages. Subjects self-reported if they did not read or had difficulty reading newsprint. 13.8% of subjects (274/1981) had dry eye symptoms and 3.1% (62/1981) had clinically significant dry eye. There was no difference in reading speed between subjects with dry eye symptoms or clinically significant dry eye and their controls (p=0.99 and 0.78, respectively) in multivariable models. Compared with asymptomatic subjects, however, subjects with dry eye symptoms were more likely to report reading difficulty (OR=1.7, 95% CI 1.3 to 2.4, p<0.01) and not reading newsprint (OR=1.9, 95% CI 1.0 to 3.6, p=0.04). Similarly, subjects with clinically significant dry eye were more likely to report difficulty reading newsprint (OR=2.5, 95% CI 1.4 to 4.5, p<0.01) or not reading newsprint at all (OR=4.1, 95% CI 1.6 to 10.7, p<0.01) as compared with subjects without dry eye signs or symptoms. Dry eye did not significantly affect reading speed but was associated with self-reported reading difficulty and avoidance of newspaper reading in this elderly population-based sample.

  14. A wide angle low coherence interferometry based eye length optometer

    NASA Astrophysics Data System (ADS)

    Meadway, Alexander; Siegwart, John; Wildsoet, Christine; Norton, Thomas; Zhang, Yuhua

    2015-03-01

    Interest in eye growth regulation has burgeoned with the rise in myopia prevalence world-wide. Eye length and eye shape are fundamental metrics for related research, but current in vivo measurement techniques are generally limited to the optical axis of the eye. We describe a high resolution, time domain low coherence interferometry based optometer for measuring the eye length of small animals over a wide field of view. The system is based upon a Michelson interferometer using a superluminescent diode as a source, including a sample arm and a reference arm. The sample arm is split into two paths by a polarisation beam splitter; one focuses the light on the cornea and the other focuses the light on the retina. This method has a high efficiency of detection for reflections from both surfaces. The reference arm contains a custom high speed linear motor with 25 mm stroke and equipped with a precision displacement encoder. Light reflected from the cornea and the retina is combined with the reference beam to generate low coherence interferograms. Two galvo scanners are employed to steer the light to different angles so that the eye length over a field of view of 20° × 20° can be measured. The system has an axial resolution of 6.8 μm (in air) and the motor provides accurate movement, allowing for precise and repeatable measurement of coherence peak positions. Example scans from a tree shrew are presented.

  15. simEye: Computer-based simulation of visual perception under various eye defects using Zernike polynomials.

    PubMed

    Fink, Wolfgang; Micol, Daniel

    2006-01-01

    We describe a computer eye model that allows for aspheric surfaces and a three-dimensional computer-based ray-tracing technique to simulate optical properties of the human eye and visual perception under various eye defects. Eye surfaces, such as the cornea, eye lens, and retina, are modeled or approximated by a set of Zernike polynomials that are fitted to input data for the respective surfaces. A ray-tracing procedure propagates light rays using Snell's law of refraction from an input object (e.g., digital image) through the eye under investigation (i.e., eye with defects to be modeled) to form a retinal image that is upside down and left-right inverted. To obtain a first-order realistic visual perception without having to model or simulate the retina and the visual cortex, this retinal image is then back-propagated through an emmetropic eye (e.g., Gullstrand exact schematic eye model with no additional eye defects) to an output screen of the same dimensions and at the same distance from the eye as the input object. Visual perception under instances of emmetropia, regular astigmatism, irregular astigmatism, and (central symmetric) keratoconus is simulated and depicted. In addition to still images, the computer ray-tracing tool presented here (simEye) permits the production of animated movies. These developments may have scientific and educational value. This tool may facilitate the education and training of both the public, for example, patients before undergoing eye surgery, and those in the medical field, such as students and professionals. Moreover, simEye may be used as a scientific research tool to investigate optical lens systems in general and the visual perception under a variety of eye conditions and surgical procedures such as cataract surgery and laser assisted in situ keratomileusis (LASIK) in particular.

  16. Eye irritation potential: palm-based methyl ester sulphonates.

    PubMed

    Yusof, Nor Zuliana; Azizul Hasan, Zafarizal Aldrin; Abd Maurad, Zulina; Idris, Zainab

    2017-07-31

    To evaluate eye irritation potential of palm-based methyl ester sulphonates (MES) of different chain lengths; C12, C14, C16, C16:18. The Bovine Corneal Opacity and Permeability test method (BCOP), OECD Test Guideline 437, was used as an initial step to study the inducing effect of palm-based MES on irreversible eye damage. The second assessment involved the use of reconstructed human corneal-like epithelium test method, OECD Test Guideline 492 using SkinEthic™ Human Corneal Epithelium to study the potential effect of palm-based MES on eye irritancy. The palm-based MES were prepared in 10% solution (w/v) in deionized water and tested as a liquid and surfactant test substances whereby both test conducted according to the liquid/surfactant treatment protocol. The preliminary BCOP results showed that palm-based MES; C12, C14, C16, C16:18 were not classified as severe eye irritants test substances with in vitro irritancy score between 3 and the threshold level of 55. The second evaluation using SkinEthic™ HCE model showed that palm-based MES; C12, C14, C16, C16:18 and three commercial samples were potentially irritants to the eyes with mean tissue viability ? 60% and classified as Category 2 according to United Nations Globally Harmonized System of Classification and Labelling of Chemicals. However, there are some limitations of the proposed ocular irritation classification of palm-based MES due to insolubility of long chain MES in 10% solution (w/v) in deionized water. Therefore, future studies to clarify the eye irritation potential of the palm-based MES will be needed, and could include; methods to improve the test substance solubility, use of test protocol for solids, and/or inclusion of a benchmark anionic surfactant, such as sodium dodecyl sulphate within the study design.

  17. Video-based eye tracking for neuropsychiatric assessment.

    PubMed

    Adhikari, Sam; Stark, David E

    2017-01-01

    This paper presents a video-based eye-tracking method, ideally deployed via a mobile device or laptop-based webcam, as a tool for measuring brain function. Eye movements and pupillary motility are tightly regulated by brain circuits, are subtly perturbed by many disease states, and are measurable using video-based methods. Quantitative measurement of eye movement by readily available webcams may enable early detection and diagnosis, as well as remote/serial monitoring, of neurological and neuropsychiatric disorders. We successfully extracted computational and semantic features for 14 testing sessions, comprising 42 individual video blocks and approximately 17,000 image frames generated across several days of testing. Here, we demonstrate the feasibility of collecting video-based eye-tracking data from a standard webcam in order to assess psychomotor function. Furthermore, we were able to demonstrate through systematic analysis of this data set that eye-tracking features (in particular, radial and tangential variance on a circular visual-tracking paradigm) predict performance on well-validated psychomotor tests.

  18. Investigation of cue-based vertical and horizontal eye movements with electroencephalographic and eye-tracking data.

    PubMed

    Kaiser, Vera; Brunner, Clemens; Leeb, Robert; Neuper, Christa; Pfurtscheller, Gert

    2009-11-01

    This study investigates the influence of eye movement direction on patterns of brain activation. The processing of visual input was investigated by quantifying event-related desynchronization (ERD) in the electroencephalogram (EEG). Cue-based vertical and horizontal eye movements were measured with an eye tracker. Differences between vertical and horizontal eye movements in EEG and eye-tracking data were analyzed. The results of this study indicate that vertical and horizontal eye movements result in different ERD and ERS patterns. During the execution of a saccade vertical eye movements are accompanied by a stronger ERS whereas the fixation of the cue is related to stronger ERD after horizontal eye movements. The fact that eye movements are correlated with a desynchronization of activity in parietal and occipital areas is reasonable, since visual information processing and visual control of movements take place there. Stronger ERD in the alpha band could be related to the fact that information processing tasks like e.g. reading require mostly horizontal and not vertical eye movements. The differences in the ERD/ERS patterns in relation to the direction of the eye movement should be considered in future investigations and taken into account in the construction of paradigms.

  19. RapidEye satellite based geo-information system

    NASA Astrophysics Data System (ADS)

    Krischke, M.; Niemeyer, W.; Scherer, S.

    2000-03-01

    It has been found that the ability to offer a guaranteed delivery of information products is the key for any successful commercial Earth observation service. This understanding led to the definition of the RapidEye system and the foundation of the RapidEye AG. RapidEye is a satellite based remote sensing system which permits to have from any point on Earth, at least daily a multispectral (and optionally stereo) imaging capability with a resolution of 5-7 m. It is aimed at establishing an efficient operation for the rapid and accurate reception and processing of thematic information of the Earth's surface and to establish a reliable and sustained service for customers. RapidEye is set up in several steps. The individual steps can be realised according to the system's acceptance on the market. Four satellites are planned already for the first step which permits a revisiting rate of 1/day. In its final configuration, RapidEye consists of a chain of Earth observation satellites which optionally communicate with one another via communication links.

  20. Using Eye Blinking for EOG-Based Robot Control

    NASA Astrophysics Data System (ADS)

    Duguleana, Mihai; Mogan, Gheorghe

    This paper proposes a new approach to real-time robot controlling by integrating an Electrooculography (EOG) measuring device within human-robot interaction (HRI). Our study focuses on controlling robots using EOG for fulfilling elementary robot activities such as basic motor movements and environment interaction. A new EOG-based HRI paradigm has been developed on the specific defined problem of eye blinking. The resulted model is tested using biometric capturing equipment. We propose a simple algorithm for real-time identification and processing of signals produced by eyes during blinking phases. We present the experimental setup and the results of the experiment. We conclude by listing further research issues.

  1. Measuring eye movements during locomotion: filtering techniques for obtaining velocity signals from a video-based eye monitor

    NASA Technical Reports Server (NTRS)

    Das, V. E.; Thomas, C. W.; Zivotofsky, A. Z.; Leigh, R. J.

    1996-01-01

    Video-based eye-tracking systems are especially suited to studying eye movements during naturally occurring activities such as locomotion, but eye velocity records suffer from broad band noise that is not amenable to conventional filtering methods. We evaluated the effectiveness of combined median and moving-average filters by comparing prefiltered and postfiltered records made synchronously with a video eye-tracker and the magnetic search coil technique, which is relatively noise free. Root-mean-square noise was reduced by half, without distorting the eye velocity signal. To illustrate the practical use of this technique, we studied normal subjects and patients with deficient labyrinthine function and compared their ability to hold gaze on a visual target that moved with their heads (cancellation of the vestibulo-ocular reflex). Patients and normal subjects performed similarly during active head rotation but, during locomotion, patients held their eyes more steadily on the visual target than did subjects.

  2. Feature quality-based multimodal unconstrained eye recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Du, Eliza Y.; Lin, Yong; Thomas, N. Luke; Belcher, Craig; Delp, Edward J.

    2013-05-01

    Iris recognition has been tested to the most accurate biometrics using high resolution near infrared images. However, it does not work well under visible wavelength illumination. Sclera recognition, however, has been shown to achieve reasonable recognition accuracy under visible wavelengths. Combining iris and sclera recognition together can achieve better recognition accuracy. However, image quality can significantly affect the recognition accuracy. Moreover, in unconstrained situations, the acquired eye images may not be frontally facing. In this research, we proposed a feature quality-based multimodal unconstrained eye recognition method that combine the respective strengths of iris recognition and sclera recognition for human identification and can work with frontal and off-angle eye images. The research results show that the proposed method is very promising.

  3. Height estimations based on eye measurements throughout a gait cycle.

    PubMed

    Yang, Sylvia X M; Larsen, Peter K; Alkjær, Tine; Juul-Kristensen, Birgit; Simonsen, Erik B; Lynnerup, Niels

    2014-03-01

    Anthropometric measurements (e.g. the height to the head, nose tip, eyes or shoulders) of a perpetrator based on video material may be used in criminal cases. However, several height measurements may be difficult to assess as the perpetrators may be disguised by clothes or headwear. The eye height (EH) measurement, on the other hand, is less prone to concealment. The purpose of the present study was to investigate: (1) how the eye height varies during the gait cycle, and (2) how the eye height changes with head position. The eyes were plotted manually in APAS for 16 test subjects during a complete gait cycle. The influence of head tilt on the EH was investigated in 20 healthy men. Markers were attached to the face and the subjects were instructed to stand relaxed, tilt their head to the right, to the left, forward and backward. The marker data for the right eye were used to calculate the EH. The respective deviation and SD from the relaxed standing EH and the EH in the Frankfurt plane, left tilted, right tilted, forward tilted and backward tilted, in addition to the corresponding head tilt angles were calculated. There was no correlation between the height of the subject and the maximum vertical displacement of the EH throughout the gait cycle nor between height of the subjects and the variation of the EH throughout the gait cycle. The average maximum vertical displacement for the test subject group was 4.76 cm (± 1.56 cm). The average EH was lower when the subjects were standing in the relaxed position than in the Frankfurt plane. The average EH was higher in the relaxed position than when the subjects tilted their heads, except when they tilted their heads backwards. The subjects had a slightly larger range of motion to the right than to the left, which was not significant. The results of this study provide a range for eye height estimates and may be readily implemented in forensic case work. It can be used as a reference in height estimates in cases with height

  4. Model of the Human Eye Based on ABCD Matrix

    NASA Astrophysics Data System (ADS)

    González, G. Díaz; Castillo, M. David Iturbe

    2008-04-01

    At the moment several models of the human eye exist, nevertheless the gradient index models of the human lens (crystalline) have received little attention in optometry and vision sciences, although they consider how the refractive index and the refracting power can change with the accommodation. On the other hand, in study fields like ophthalmology and optometry, exist cases where there is a lack of information about the factors that influence the change of refractive power and therefore the focal length of the eye. By such reason, in this paper we present a model of the human eye based on the ABCD matrix in order to describe the propagation of light rays, that can be understood by professional people in optics, ophthalmology and optometry, and the dispersions of the different ocular mediums are taken into account,. The aim of the model is to obtain data about the refractive power of the eye under different considerations, such as: changes in wavelength, radius of curvature and thicknesses of the ocular mediums. We present results of simulations in Matlab of our model, assuming that the object is punctual and is placed to a certain distance of the eye, and considering at the beginning to the crystalline like a medium with fixed refractive index, and after like a gradient lens. By means of graphs, we show the total refractive power of the eye and its form and type of dependence with respect to variations in radius of curvature and thicknesses of the cornea and crystalline, as well as variations in the thickness of the previous and later cameras.

  5. Enhancing eye-movement-based biometric identification method by using voting classifiers

    NASA Astrophysics Data System (ADS)

    Kasprowski, Pawel; Ober, Jozef

    2005-03-01

    Eye movements contain a lot of information about human being. The way the eyes are moving is very complicated and eye movement patterns has been subject of studies for over 100 years. However, surprisingly, eye movement based identification is a quite new idea presented for the first time during the Biometrics'2003 Conference in London [17]. The method has several significant advantages: compiles behavioral and physiological properties of human body, it is difficult to forge and it is affordable-with a number of ready-to-use eye registering devices (so called eye trackers). The paper introduces the methodology and presents results of the first eye movement based authorization tests.

  6. 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.

  7. Comparison of novel lipid-based eye drops with aqueous eye drops for dry eye: a multicenter, randomized controlled trial

    PubMed Central

    Simmons, Peter A; Carlisle-Wilcox, Cindy; Vehige, Joseph G

    2015-01-01

    Background Dry eye may be caused or exacerbated by deficient lipid secretion. Recently, lipid-containing artificial tears have been developed to alleviate this deficiency. Our study compared the efficacy, safety, and acceptability of lipid-containing eye drops with that of aqueous eye drops. Methods A non-inferiority, randomized, parallel-group, investigator-masked multicenter trial was conducted. Subjects with signs and symptoms of dry eye were randomized to use one of two lipid-containing artificial tears, or one of two aqueous artificial tears. Subjects instilled assigned drops in each eye at least twice daily for 30 days. The primary efficacy analysis tested non-inferiority of a preservative-free lipid tear formulation (LT UD) to a preservative-free aqueous tear formulation (AqT UD) for change in Ocular Surface Disease Index (OSDI) score from baseline at day 30. Secondary measures included OSDI at day 7, tear break-up time (TBUT), corneal and conjunctival staining, Schirmer’s test, acceptability and usage questionnaires, and safety assessments. Results A total of 315 subjects were randomized and included in the analyses. Subjects reported instilling a median of three doses of study eye drops per day in all groups. At days 7 and 30, all groups showed statistically significant improvements from baseline in OSDI (P<0.001) and TBUT (P≤0.005). LT UD was non-inferior to AqT UD for mean change from baseline in OSDI score at day 30. No consistent or clinically relevant differences for the other efficacy variables were observed. Acceptability was generally similar across the groups and there was a low incidence of adverse events. Conclusion In this heterogeneous population of dry eye subjects, there were no clinically significant differences in safety, effectiveness, and acceptability between lipid-containing artificial tears and aqueous eye drops. The results suggest that lipid-containing artificial tears can be used to counteract lipid deficiency that is common in

  8. Characterization of porcine eyes based on autofluorescence lifetime imaging

    NASA Astrophysics Data System (ADS)

    Batista, Ana; Breunig, Hans Georg; Uchugonova, Aisada; Morgado, António Miguel; König, Karsten

    2015-03-01

    Multiphoton microscopy is a non-invasive imaging technique with ideal characteristics for biological applications. In this study, we propose to characterize three major structures of the porcine eye, the cornea, crystalline lens, and retina using two-photon excitation fluorescence lifetime imaging microscopy (2PE-FLIM). Samples were imaged using a laser-scanning microscope, consisting of a broadband sub-15 femtosecond (fs) near-infrared laser. Signal detection was performed using a 16-channel photomultiplier tube (PMT) detector (PML-16PMT). Therefore, spectral analysis of the fluorescence lifetime data was possible. To ensure a correct spectral analysis of the autofluorescence lifetime data, the spectra of the individual endogenous fluorophores were acquired with the 16-channel PMT and with a spectrometer. All experiments were performed within 12h of the porcine eye enucleation. We were able to image the cornea, crystalline lens, and retina at multiple depths. Discrimination of each structure based on their autofluorescence intensity and lifetimes was possible. Furthermore, discrimination between different layers of the same structure was also possible. To the best of our knowledge, this was the first time that 2PE-FLIM was used for porcine lens imaging and layer discrimination. With this study we further demonstrated the feasibility of 2PE-FLIM to image and differentiate three of the main components of the eye and its potential as an ophthalmologic technique.

  9. Research on moving object detection based on frog's eyes

    NASA Astrophysics Data System (ADS)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

    On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

  10. Optic nerve head perfusion in normal eyes and eyes with glaucoma using optical coherence tomography-based microangiography

    PubMed Central

    Chen, Chieh-Li; Bojikian, Karine D.; Gupta, Divakar; Wen, Joanne C.; Zhang, Qinqin; Xin, Chen; Kono, Rei; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.

    2016-01-01

    Background To investigate the differences of perfusion in the optic nerve head (ONH) between normal and glaucomatous eyes using optical microangiography (OMAG) based optical coherence tomography (OCT) angiography technique. Methods One eye from each subject was scanned with a 68 kHz Cirrus 5000 HD-OCT-based OMAG prototype system centered at the ONH (Carl Zeiss Meditec Inc, Dublin, CA, USA). Microvascular images were generated from the OMAG dataset by detecting the differences in OCT signal between consecutive B-scans. The pre-laminar layer (preLC) was isolated by a semi-automatic segmentation program. En face OMAG images for preLC were generated using signals with highest blood flow signal intensity. ONH perfusion was quantified as flux, vessel area density, and normalized flux within the ONH. Standard t-tests were performed to analyze the ONH perfusion differences between normal and glaucomatous eyes. Linear regression models were constructed to analyze the correlation between ONH perfusion and other clinical measurements. Results Twenty normal and 21 glaucoma subjects were enrolled. Glaucomatous eyes had significantly lower ONH perfusion in preLC in all three perfusion metrics compared to normal eyes (P≤0.0003). Significant correlations between ONH perfusion and disease severity as well as structural changes were detected in glaucomatous eyes (P≤0.012). Conclusions ONH perfusion detected by OMAG showed significant differences between glaucoma and normal controls and was significantly correlated with disease severity and structural defects in glaucomatous eyes. ONH perfusion measurement using OMAG may provide useful information for detection and monitoring of glaucoma. PMID:27190764

  11. CUE: counterfeit-resistant usable eye movement-based authentication via oculomotor plant characteristics and complex eye movement patterns

    NASA Astrophysics Data System (ADS)

    Komogortsev, Oleg V.; Karpov, Alexey; Holland, Corey D.

    2012-06-01

    The widespread use of computers throughout modern society introduces the necessity for usable and counterfeit-resistant authentication methods to ensure secure access to personal resources such as bank accounts, e-mail, and social media. Current authentication methods require tedious memorization of lengthy pass phrases, are often prone to shouldersurfing, and may be easily replicated (either by counterfeiting parts of the human body or by guessing an authentication token based on readily available information). This paper describes preliminary work toward a counterfeit-resistant usable eye movement-based (CUE) authentication method. CUE does not require any passwords (improving the memorability aspect of the authentication system), and aims to provide high resistance to spoofing and shoulder-surfing by employing the combined biometric capabilities of two behavioral biometric traits: 1) oculomotor plant characteristics (OPC) which represent the internal, non-visible, anatomical structure of the eye; 2) complex eye movement patterns (CEM) which represent the strategies employed by the brain to guide visual attention. Both OPC and CEM are extracted from the eye movement signal provided by an eye tracking system. Preliminary results indicate that the fusion of OPC and CEM traits is capable of providing a 30% reduction in authentication error when compared to the authentication accuracy of individual traits.

  12. Collision and containment detection between biomechanically based eye muscle volumes.

    PubMed

    Santana Sosa, Graciela; Kaltofen, Thomas

    2011-01-01

    Collision and containment detection between three-dimensional objects is a common requirement in simulation systems. However, few solutions exist when exclusively working with deformable bodies. In our ophthalmologic diagnostic software system, the extraocular eye muscles are represented by surface models, which have been reconstructed from magnetic resonance images. Those models are projected onto the muscle paths calculated by the system's biomechanical model. Due to this projection collisions occur. For their detection, three approaches have been implemented, which we present in this paper: one based on image-space techniques using OpenGL, one based on the Bullet physics library and one using an optimized space-array data structure together with software rendering. Finally, an outlook on a possible response to the detected collisions is given.

  13. A hemispherical electronic eye camera based on compressible silicon optoelectronics.

    PubMed

    Ko, Heung Cho; Stoykovich, Mark P; Song, Jizhou; Malyarchuk, Viktor; Choi, Won Mook; Yu, Chang-Jae; Geddes, Joseph B; Xiao, Jianliang; Wang, Shuodao; Huang, Yonggang; Rogers, John A

    2008-08-07

    The human eye is a remarkable imaging device, with many attractive design features. Prominent among these is a hemispherical detector geometry, similar to that found in many other biological systems, that enables a wide field of view and low aberrations with simple, few-component imaging optics. This type of configuration is extremely difficult to achieve using established optoelectronics technologies, owing to the intrinsically planar nature of the patterning, deposition, etching, materials growth and doping methods that exist for fabricating such systems. Here we report strategies that avoid these limitations, and implement them to yield high-performance, hemispherical electronic eye cameras based on single-crystalline silicon. The approach uses wafer-scale optoelectronics formed in unusual, two-dimensionally compressible configurations and elastomeric transfer elements capable of transforming the planar layouts in which the systems are initially fabricated into hemispherical geometries for their final implementation. In a general sense, these methods, taken together with our theoretical analyses of their associated mechanics, provide practical routes for integrating well-developed planar device technologies onto the surfaces of complex curvilinear objects, suitable for diverse applications that cannot be addressed by conventional means.

  14. Rapid micromotor-based naked-eye immunoassay.

    PubMed

    de Ávila, Berta Esteban-Fernández; Zhao, Mingjiao; Campuzano, Susana; Ricci, Francesco; Pingarrón, José M; Mascini, Marcello; Wang, Joseph

    2017-05-15

    A dynamic micromotor-based immunoassay, exemplified by cortisol detection, based on the use of tubular micromotors functionalized with a specific antibody is described. The use of antibody-functionalized micromotors offers huge acceleration of both direct and competitive cortisol immunoassays, along with greatly enhanced sensitivity of direct and competitive immunoassays. The dramatically improved speed and sensitivity reflect the greatly increased likelihood of antibody-cortisol contacts and fluid mixing associated with the dynamic movement of these microtube motors and corresponding bubble generation that lead to a highly efficient and rapid recognition process. Rapid naked-eye detection of cortisol in the sample is achieved in connection to use of horseradish peroxidase (HRP) tag and TMB/H2O2 system. Key parameters of the competitive immunoassay (e.g., incubation time and reaction volume) were optimized. This fast visual micromotor-based sensing approach enables "on the move" specific detection of the target cortisol down to 0.1μgmL(-1) in just 2min, using ultrasmall (50µL) sample volumes.

  15. Assessment of eye fatigue caused by 3D displays based on multimodal measurements.

    PubMed

    Bang, Jae Won; Heo, Hwan; Choi, Jong-Suk; Park, Kang Ryoung

    2014-09-04

    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.

  16. Post-saccadic oscillations in eye movement data recorded with pupil-based eye trackers reflect motion of the pupil inside the iris.

    PubMed

    Nyström, Marcus; Hooge, Ignace; Holmqvist, Kenneth

    2013-11-01

    Current video eye trackers use information about the pupil center to estimate orientation and movement of the eye. While dual Purkinje eye trackers suffer from lens wobble and scleral search coils may be influenced by contact lens slippage directly after saccades, it is not known whether pupil-based eye trackers produces similar artifacts in the data. We recorded eye movements from participants making repetitive, horizontal saccades and compared the movement in the data with pupil- and iris movements extracted from the eye images. Results showed that post-saccadic instabilities clearly exist in data recorded with a pupil-based eye tracker. They also exhibit a high degree of reproducibility across saccades and within participants. While the recorded eye movement data correlated well with the movement of the pupil center, the iris center showed only little post-saccadic movement. This means that the pupil moves relative to the iris during post-saccadic eye movements, and that the eye movement data reflect pupil movement rather than eyeball rotation. Besides introducing inaccuracies and additional variability in the data, the pupil movement inside the eyeball influences the decision of when a saccade should end and the subsequent fixation should begin, and consequently higher order analyses based on fixations and saccades.

  17. Comparison of in vitro eye irritation potential by bovine corneal opacity and permeability (BCOP) assay to erythema scores in human eye sting test of surfactant-based formulations.

    PubMed

    Cater, Kathleen C; Harbell, John W

    2008-01-01

    The bovine corneal opacity and permeability (BCOP) assay can be used to predict relative eye irritation potential of surfactant-based personal care formulations relative to a corporate benchmark. The human eye sting test is typically used to evaluate product claims of no tears/no stinging for children's bath products. A preliminary investigation was conducted to test a hypothesis that the BCOP assay could be used as a prediction model for relative ranking of human eye irritation responses under conditions of a standard human eye sting test to surfactant-based formulations. BCOP assays and human eye sting tests were conducted on 4 commercial and 1 prototype body wash (BW) developed specifically for children or as mild bath products. In the human eye sting test, 10 mul of a 10% dosing solution is instilled into one eye of each panelist (n = 20), and the contralateral eye is dosed with sterile water as a control. Bulbar conjunctival erythema responses of each eye are graded at 30 seconds by an ophthalmologist. The BCOP assay permeability values (optical density at 490 nm [OD(490)]) for the 5 BWs ranged from 0.438 to 1.252 (i.e., least to most irritating). By comparison, the number of panelists exhibiting erythema responses (mild to moderately pink) ranged from 3 of 20 panelists for the least irritating BW to 10 of 20 panelists for the most irritating BW tested. The relative ranking of eye irritation potential of the 5 BWs in the BCOP assay compares favorably with the relative ranking of the BWs in the human eye sting test. Based on these findings, the permeability endpoint of the BCOP assay, as described for surfactant-based formulations, showed promise as a prediction model for relative ranking of conjunctival erythema responses in the human eye. Consequently, screening of prototype formulations in the BCOP assay would allow for formula optimization of mild bath products prior to investment in a human eye sting test.

  18. Head-mounted computer interface based on eye tracking

    NASA Astrophysics Data System (ADS)

    Schroeder, William E.

    1993-10-01

    A head-mounted computer interface using eye-tracking as a `pointer' was demonstrated at the Third Annual Weapons Technology Review and Training Exposition at San Diego in January 1992, and is under further development for military and civilian applications. in this interface, the computer interprets eye gaze direction just as it would input from a mouse or trackball. This technology makes possible computer-human interaction with many ideal aspects: complete portability, hands-free operation, silent, secure operation anywhere and any time. Commercial systems using control inputs from the tracked eye are available and effective within their limits, but size, weight, and cost have been barriers to wider use. This paper describes the latest head-mounted eye tracking display (HETD) development prototype. We are exploring the technological limits of current and near-term lighting, detector, and lens technology to project the feasibility of this device.

  19. A Novel Hybrid Mental Spelling Application Based on Eye Tracking and SSVEP-Based BCI.

    PubMed

    Stawicki, Piotr; Gembler, Felix; Rezeika, Aya; Volosyak, Ivan

    2017-04-05

    Steady state visual evoked potentials (SSVEPs)-based Brain-Computer interfaces (BCIs), as well as eyetracking devices, provide a pathway for re-establishing communication for people with severe disabilities. We fused these control techniques into a novel eyetracking/SSVEP hybrid system, which utilizes eye tracking for initial rough selection and the SSVEP technology for fine target activation. Based on our previous studies, only four stimuli were used for the SSVEP aspect, granting sufficient control for most BCI users. As Eye tracking data is not used for activation of letters, false positives due to inappropriate dwell times are avoided. This novel approach combines the high speed of eye tracking systems and the high classification accuracies of low target SSVEP-based BCIs, leading to an optimal combination of both methods. We evaluated accuracy and speed of the proposed hybrid system with a 30-target spelling application implementing all three control approaches (pure eye tracking, SSVEP and the hybrid system) with 32 participants. Although the highest information transfer rates (ITRs) were achieved with pure eye tracking, a considerable amount of subjects was not able to gain sufficient control over the stand-alone eye-tracking device or the pure SSVEP system (78.13% and 75% of the participants reached reliable control, respectively). In this respect, the proposed hybrid was most universal (over 90% of users achieved reliable control), and outperformed the pure SSVEP system in terms of speed and user friendliness. The presented hybrid system might offer communication to a wider range of users in comparison to the standard techniques.

  20. A Novel Hybrid Mental Spelling Application Based on Eye Tracking and SSVEP-Based BCI

    PubMed Central

    Stawicki, Piotr; Gembler, Felix; Rezeika, Aya; Volosyak, Ivan

    2017-01-01

    Steady state visual evoked potentials (SSVEPs)-based Brain-Computer interfaces (BCIs), as well as eyetracking devices, provide a pathway for re-establishing communication for people with severe disabilities. We fused these control techniques into a novel eyetracking/SSVEP hybrid system, which utilizes eye tracking for initial rough selection and the SSVEP technology for fine target activation. Based on our previous studies, only four stimuli were used for the SSVEP aspect, granting sufficient control for most BCI users. As Eye tracking data is not used for activation of letters, false positives due to inappropriate dwell times are avoided. This novel approach combines the high speed of eye tracking systems and the high classification accuracies of low target SSVEP-based BCIs, leading to an optimal combination of both methods. We evaluated accuracy and speed of the proposed hybrid system with a 30-target spelling application implementing all three control approaches (pure eye tracking, SSVEP and the hybrid system) with 32 participants. Although the highest information transfer rates (ITRs) were achieved with pure eye tracking, a considerable amount of subjects was not able to gain sufficient control over the stand-alone eye-tracking device or the pure SSVEP system (78.13% and 75% of the participants reached reliable control, respectively). In this respect, the proposed hybrid was most universal (over 90% of users achieved reliable control), and outperformed the pure SSVEP system in terms of speed and user friendliness. The presented hybrid system might offer communication to a wider range of users in comparison to the standard techniques. PMID:28379187

  1. Optimization of hyaluronan-based eye drop formulations.

    PubMed

    Salzillo, Rosanna; Schiraldi, Chiara; Corsuto, Luisana; D'Agostino, Antonella; Filosa, Rosanna; De Rosa, Mario; La Gatta, Annalisa

    2016-11-20

    Hyaluronan (HA) is frequently incorporated in eye drops to extend the pre-corneal residence time, due to its viscosifying and mucoadhesive properties. Hydrodynamic and rheological evaluations of commercial products are first accomplished revealing molecular weights varying from about 360 to about 1200kDa and viscosity values in the range 3.7-24.2mPa s. The latter suggest that most products could be optimized towards resistance to drainage from the ocular surface. Then, a study aiming to maximize the viscosity and mucoadhesiveness of HA-based preparations is performed. The effect of polymer chain length and concentration is investigated. For the whole range of molecular weights encountered in commercial products, the concentration maximizing performance is identified. Such concentration varies from 0.3 (wt%) for a 1100kDa HA up to 1.0 (wt%) for a 250kDa HA, which is 3-fold higher than the highest concentration on the market. The viscosity and mucoadhesion profiles of optimized formulations are superior than commercial products, especially under conditions simulating in vivo blinking. Thus longer retention on the corneal epithelium can be predicted. An enhanced capacity to protect corneal porcine epithelial cells from dehydration is also demonstrated in vitro. Overall, the results predict formulations with improved efficacy. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  2. Interactive facial caricaturing system based on eye camera

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tsuyoshi; Tominaga, Masafumi; Koshimizu, Hiroyasu

    2003-04-01

    Face is the most effective visual media for supporting human interface and communication. We have proposed a typical KANSEI machine vision system to generate the facial caricature so far. The basic principle of this system uses the "mean face assumption" to extract individual features of a given face. This system did not provide for feedback from the gallery of the caricature; therefore, to allow for such feedback, in this paper, we propose a caricaturing system by using the KANSEI visual information acquired from the Eye-camera mounted on the head of a gallery, because it is well know that the gaze distribution represents not only where but also how he is looking at the face. The caricatures created in this way could be based on several measures which are provided from the distribution of the number of fixations to the facial parts, the number of times the gaze came to a particular area of the face, and the matrix of the transitions from a facial region to the other. These measures of the gallery"s KANSEI information were used to create caricatures with feedback from the gallery.

  3. 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

  4. A naked-eye based strategy for semiquantitative immunochromatographic assay.

    PubMed

    Zhang, Daohong; Li, Peiwu; Zhang, Qi; Li, Ran; Zhang, Wen; Ding, Xiaoxia; Li, Chang Ming

    2012-08-31

    It is critical to develop a cost-effective quantitative/semiquantitative assay for rapid diagnosis and on-site detection of toxic or harmful substances. Here, a naked-eye based semiquantitative immunochromatographic strip (NSI-strip) was developed, on which three test lines (TLs, TL-I, TL-II and TL-III) were dispensed on a nitrocellulose membrane to form the test zone. Similar as the traditional strip assay for small molecule, the NSI-strip assay was also based on the competitive theory, difference was that the analyte competed three times with the capture reagent for the limited number of antibody binding sites. After the assay, the number of TLs developed in the test zone was inversely proportional to the analyte concentration, thus analyte content levels could be determined by observing the appeared number of TLs. Taking aflatoxin B(1) as the model analyte, visual detection limit of the NSI-strip was 0.06 ng mL(-1) and threshold concentrations for TL-I-III were 0.125, 0.5, and 2.0 ng mL(-1), respectively. Therefore, according to the appeared number of TLs, the following concentration ranges would be detectable by visual examination: 0-0.06 ng mL(-1) (negative samples), and 0.06-0.125 ng mL(-1), 0.125-0.5 ng mL(-1), 0.5-2.0 ng mL(-1) and >2.0 ng mL(-1) (positive samples). That was to say, compared to traditional strips the NSI-strip could offer more parameter information of the target analyte content. In this way, the NSI-strip improved the qualitative presence/absence detection of traditional strips by measuring the content (range) of target analytes semiquantitatively.

  5. Optimizations and Applications in Head-Mounted Video-Based Eye Tracking

    ERIC Educational Resources Information Center

    Li, Feng

    2011-01-01

    Video-based eye tracking techniques have become increasingly attractive in many research fields, such as visual perception and human-computer interface design. The technique primarily relies on the positional difference between the center of the eye's pupil and the first-surface reflection at the cornea, the corneal reflection (CR). This…

  6. Effects of Bilateral Eye Movements on Gist Based False Recognition in the DRM Paradigm

    ERIC Educational Resources Information Center

    Parker, Andrew; Dagnall, Neil

    2007-01-01

    The effects of saccadic bilateral (horizontal) eye movements on gist based false recognition was investigated. Following exposure to lists of words related to a critical but non-studied word participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Subsequent testing of recognition memory revealed that those who…

  7. Optimizations and Applications in Head-Mounted Video-Based Eye Tracking

    ERIC Educational Resources Information Center

    Li, Feng

    2011-01-01

    Video-based eye tracking techniques have become increasingly attractive in many research fields, such as visual perception and human-computer interface design. The technique primarily relies on the positional difference between the center of the eye's pupil and the first-surface reflection at the cornea, the corneal reflection (CR). This…

  8. Effects of Bilateral Eye Movements on Gist Based False Recognition in the DRM Paradigm

    ERIC Educational Resources Information Center

    Parker, Andrew; Dagnall, Neil

    2007-01-01

    The effects of saccadic bilateral (horizontal) eye movements on gist based false recognition was investigated. Following exposure to lists of words related to a critical but non-studied word participants were asked to engage in 30s of bilateral vs. vertical vs. no eye movements. Subsequent testing of recognition memory revealed that those who…

  9. Comparison of Hospital Versus Rural Eye Camp Based Pediatric Cataract Surgery

    PubMed Central

    Ram, Jagat; Sukhija, Jaspreet; Thapa, Babu R.; Arya, Virendra K.

    2012-01-01

    Purpose: To compare the outcomes of pediatric cataract surgery with intraocular lens (IOL) implantation in an eye camp setting and tertiary care center. Materials and Methods: Children aged 5-16 years with visually significant cataract underwent phacoaspiration with IOL implantation in an eye camp (eye camp group) or tertiary care center (TCC group). All surgeries incorporated contemporary microsurgical techniques with implantation of polymethyl-methacrylate (PMMA) IOL. Major postoperative complications were managed at a tertiary care center. Postoperative complications, visual acuity and compliance were evaluated using the Chi-square test. A P value less then 0.05 was considered as statistically significant. Results: The cohort comprised 59 children in the eye camp group and 48 children in the TCC group. Thirty two of fifty nine (54.23%) eyes in the eye camp group and 30/48 (62.5%) eyes in the TCC group achieved 20/40 or better best corrected visual acuity (BCVA) postoperatively. Postoperatively, 36 (61%) eyes in the eye camp group and 22 (45.83%) eyes in the TCC group required Nd: YAG laser capsulotomy or a pars plana membranectomy. (P> 0.05) The most striking feature was loss to follow up. In the eye camp group, loss to follow was 20% at one year, 49% at two years, 62% at 3 years and 67% at 4 years compared to 12.5, 21, 27 and 33% respectively in the TCC group (P<0.05, all cases). Conclusions: The outcomes of camp and tertiary care center (hospital) based pediatric cataract surgery were similar. However, the major drawback of camp based surgery was loss to follow up which eventually affected the management of amblyopia and postoperative complications. PMID:22346130

  10. Context-Based Questions: Optics in Animal Eyes

    ERIC Educational Resources Information Center

    Kaltakci, Derya; Eryilmaz, Ali

    2011-01-01

    Context is important as a motivational factor for student involvement with physics. The diversity in the types and the functions of animal eyes is an excellent context in which to achieve this goal. There exists a range of subtopics in optics including pinhole, reflection, refraction, and superposition that can be discussed in the context of the…

  11. Context-Based Questions: Optics in Animal Eyes

    ERIC Educational Resources Information Center

    Kaltakci, Derya; Eryilmaz, Ali

    2011-01-01

    Context is important as a motivational factor for student involvement with physics. The diversity in the types and the functions of animal eyes is an excellent context in which to achieve this goal. There exists a range of subtopics in optics including pinhole, reflection, refraction, and superposition that can be discussed in the context of the…

  12. Quantifying saccades while walking: validity of a novel velocity-based algorithm for mobile eye tracking.

    PubMed

    Stuart, Samuel; Galna, Brook; Lord, Sue; Rochester, Lynn; Godfrey, Alan

    2014-01-01

    We validate a novel algorithm to detect saccades from raw data obtained during walking from a mobile infra-red eye-tracking device. The algorithm was based on a velocity threshold detection method, which excluded artefacts such as blinks and flickers using specific criteria. Mobile infra-red eye-tracking was performed with a group of healthy older adults (n=5) and Parkinson's disease (n=5) subjects. Saccades determined from raw eye tracker data obtained during walking using the algorithm were compared to a ground truth dataset defined as frame-by-frame visual inspection of raw eye-tracking videos. 100 trials from 10 subjects were analyzed and compared. The algorithm was highly reliable when compared to the ground truth (ICC(2,1) = 0.94), with an overall correct saccade detection percentage of 85%. This provides a simple yet robust algorithm for the analysis of mobile eye-tracking data.

  13. Intraocular lens design for treating high myopia based on individual eye model

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Wang, Zhaoqi; Wang, Yan; Zuo, Tong

    2007-02-01

    In this research, we firstly design the phakic intraocular lens (PIOL) based on individual eye model with optical design software ZEMAX. The individual PIOL is designed to correct the defocus and astigmatism, and then we compare the PIOL power calculated from the individual eye model with that from the experiential formula. Close values of PIOL power are obtained between the individual eye model and the formula, but the suggested method has more accuracy with more functions. The impact of PIOL decentration on human eye is evaluated, including rotation decentration, flat axis decentration, steep axis decentration and axial movement of PIOL, which is impossible with traditional method. To control the PIOL decentration errors, we give the limit values of PIOL decentration for the specific eye in this study.

  14. Computational multi-dimensional imaging based on compound-eye optics

    NASA Astrophysics Data System (ADS)

    Horisaki, Ryoichi; Nakamura, Tomoya; Tanida, Jun

    2014-11-01

    Artificial compound-eye optics have been used for three-dimensional information acquisition and display. It also enables us to realize a diversity of coded imaging process in each elemental optics. In this talk, we introduce our single-shot compound-eye imaging system to observe multi-dimensional information including depth, spectrum, and polarization based on compressive sensing. Furthermore it is applicable to increase the dynamic range and field-of-view. We also demonstrate an extended depth-of-field (DOF) cameras based on compound-eye optics. These extended DOF cameras physically or computationally implement phase modulations to increase the focusing range.

  15. Full 3-D OCT-based pseudophakic custom computer eye model

    PubMed Central

    Sun, M.; Pérez-Merino, P.; Martinez-Enriquez, E.; Velasco-Ocana, M.; Marcos, S.

    2016-01-01

    We compared measured wave aberrations in pseudophakic eyes implanted with aspheric intraocular lenses (IOLs) with simulated aberrations from numerical ray tracing on customized computer eye models, built using quantitative 3-D OCT-based patient-specific ocular geometry. Experimental and simulated aberrations show high correlation (R = 0.93; p<0.0001) and similarity (RMS for high order aberrations discrepancies within 23.58%). This study shows that full OCT-based pseudophakic custom computer eye models allow understanding the relative contribution of optical geometrical and surgically-related factors to image quality, and are an excellent tool for characterizing and improving cataract surgery. PMID:27231608

  16. Risk functions for human and porcine eye rupture based on projectile characteristics of blunt objects.

    PubMed

    Kennedy, Eric A; Ng, Tracy P; McNally, Craig; Stitzel, Joel D; Duma, Stephan M

    2006-11-01

    Eye ruptures are among the most devastating eye injuries and can occur in automobile crashes, sporting impacts, and military events, where blunt projectile impacts to the eye can be encountered. The purpose of this study was to develop injury risk functions for globe rupture of both human and porcine eyes from blunt projectile impacts. This study was completed in two parts by combining published eye experiments with new test data. In the first part, data from 57 eye impact tests that were reported in the literature were analyzed. Projectile characteristics such as mass, cross-sectional area, and velocity, as well as injury outcome were noted for all tests. Data were sorted by species type and areas were identified where a paucity of data existed, based on the kinetic and normalized energy of assaulting objects. For the second part, a total of 126 projectile tests were performed on human and porcine eyes. Projectiles used for these tests included blunt aluminum projectiles, BBs, foam pellets, Airsoft pellets, and paintballs. Data for each projectile were recorded prior to testing and high-speed video was used to determine projectile velocity prior to striking the eye. In part three the data were pooled for a total of 183 eye impact tests, 83 human and 100 porcine, and were analyzed to develop the injury risk criteria. Binary logistic regression was used to develop injury risk functions based on kinetic and normalized energy. Probit analysis was used to estimate confidence intervals for the injury risk functions. Porcine eyes were found to be significantly stronger than human eyes in resisting globe rupture (p=0.01). For porcine eyes a 50% risk of globe rupture was found to be 71,145 J/m2, with a confidence interval of 63,245 J/m2 to 80,390 J/m2. Human eyes were found to have a 50% risk of globe rupture at a lower, 35,519 J/m2, with confidence intervals of 32,018 J/m2 to 40,641 J/m2. The results presented in this paper are useful in estimating the risk of globe

  17. 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

  18. Improving Eye Motion Sequence Recognition Using Electrooculography Based on Context-Dependent HMM

    PubMed Central

    Shinozaki, Takahiro; Horiuchi, Yasuo; Kuroiwa, Shingo; Furui, Sadaoki; Musha, Toshimitsu

    2016-01-01

    Eye motion-based human-machine interfaces are used to provide a means of communication for those who can move nothing but their eyes because of injury or disease. To detect eye motions, electrooculography (EOG) is used. For efficient communication, the input speed is critical. However, it is difficult for conventional EOG recognition methods to accurately recognize fast, sequentially input eye motions because adjacent eye motions influence each other. In this paper, we propose a context-dependent hidden Markov model- (HMM-) based EOG modeling approach that uses separate models for identical eye motions with different contexts. Because the influence of adjacent eye motions is explicitly modeled, higher recognition accuracy is achieved. Additionally, we propose a method of user adaptation based on a user-independent EOG model to investigate the trade-off between recognition accuracy and the amount of user-dependent data required for HMM training. Experimental results show that when the proposed context-dependent HMMs are used, the character error rate (CER) is significantly reduced compared with the conventional baseline under user-dependent conditions, from 36.0 to 1.3%. Although the CER increases again to 17.3% when the context-dependent but user-independent HMMs are used, it can be reduced to 7.3% by applying the proposed user adaptation method. PMID:27774099

  19. DNA-based eye colour prediction across Europe with the IrisPlex system.

    PubMed

    Walsh, Susan; Wollstein, Andreas; Liu, Fan; Chakravarthy, Usha; Rahu, Mati; Seland, Johan H; Soubrane, Gisele; Tomazzoli, Laura; Topouzis, Fotis; Vingerling, Johannes R; Vioque, Jesus; Fletcher, Astrid E; Ballantyne, Kaye N; Kayser, Manfred

    2012-05-01

    The ability to predict Externally Visible Characteristics (EVCs) from DNA, also referred to as Forensic DNA Phenotyping (FDP), is an exciting new chapter in forensic genetics holding great promise for tracing unknown individuals who are unidentifiable via standard forensic short tandem repeat (STR) profiling. For the purpose of DNA-based eye colour prediction, we previously developed the IrisPlex system consisting of a multiplex genotyping assay and a prediction model based on genotype and phenotype data from 3804 Dutch Europeans. Recently, we performed a forensic developmental validation study of the highly sensitive IrisPlex assay, which currently represents the only validated tool available for DNA-based prediction of eye colour in forensic applications. In the present study, we validate the IrisPlex prediction model by extending our initially described model towards genotype and phenotype data from multiple European populations. We performed IrisPlex analysis on 3840 individuals from seven sites across Europe as part of the European Eye (EUREYE) study for which DNA and high-resolution eye images were available. The accuracy rate of correctly predicting an individual's eye colour as being blue or brown, above the empirically established probability threshold of 0.7, was on average 94% across all seven European populations, ranging from 91% to 98%, despite the large variation in eye colour frequencies between the populations. The overall prediction accuracies expressed by the area under the receiver characteristic operating curves (AUC) were 0.96 for blue and 0.96 for brown eyes, which is considerably higher than those established before. The IrisPlex prediction model parameters generated from this multi-population European dataset, and thus its prediction capabilities, were highly comparable to those previously established. Therefore, the increased information regarding eye colour phenotype and genotype distributions across Europe, and the system's ability to

  20. Point detection and positioning system of the target based on surface cluster eyes

    NASA Astrophysics Data System (ADS)

    Guo, Fang; Zhang, Hao; Wang, Keyi

    2010-10-01

    The research of target detection and position is a challenge task in the fields where machine vision was used to develop various systems. However, monocular vision and binocular vision traditionally are difficult to meet the applications for high resolution and high sensitivity. Because compound eye imaging system is capacity of the large field of view for moving target detection with high sensitivity, the optical system has the potential to meet the applications above mentioned. In this paper, a preliminary exploration of the surface imaging system for the characteristics of cluster eyes was made and the optical signal processing methods of cluster eyes were introduced in detail. First the structure of the cluster eyes was described and the imaging channels of cluster eyes were ray traced with Zemax. Then based on the surface imaging mechanism with clusters eyes, the center of gravity of image space for target was extracted. Subsequently by the neural networks training based on LM (Levenberg-Marquardt) algorithm, the non-linear relationship between target and image was effectively calibrated. Finally, the corresponding relationship between target point and its image point among the various channels was established. The experimental results show that the multicast visual imaging systems are capable of providing the information of target azimuth and distance. Some attempts to study the systems were made to achieve high resolution, high sensitivity of target detection and positioning tasks. At the same time the surface imaging system also laid a solid foundation for the large compound eye imaging system from theory to practical application.

  1. Robot Arm Control and Having Meal Aid System with Eye Based Human-Computer Interaction (HCI)

    NASA Astrophysics Data System (ADS)

    Arai, Kohei; Mardiyanto, Ronny

    Robot arm control and having meal aid system with eye based HCI is proposed. The proposed system allows disabled person to select desirable food from the meal tray by their eyes only. Robot arm which is used for retrieving the desirable food is controlled by human eye. At the tip of the robot arm, tiny camera is equipped. Disabled person wear a glass of which a single Head Mount Display: HMD and tiny camera is mounted so that disabled person can take a look at the desired food and retrieve it by looking at the food displayed onto HMD. Experimental results show that disabled person can retrieve the desired food successfully. It also is confirmed that robot arm control by eye based HCI is much faster than that by hands.

  2. Office based multi-functional anterior eye segment optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Lim, Yiheng; Yamanari, Masahiro; Hong, Young-Joo; Makita, Shuichi; Miura, Masahiro; Yasuno, Yoshiaki

    2012-03-01

    An office based Doppler and polarization sensitive swept-source optical coherence tomography (Doppler-PS-SS-OCT) was developed for diagnosis and evaluation of abnormalities of anterior eye segment in clinic. A healthy eye was measured in vivo by the Doppler PS-OCT. The results showed that the Doppler PS-OCT may have potential to identify blood vessels and discriminate fibrous tissues in abnormalities, such as scarring in bleb, and scleral inflammation.

  3. The 'Quiet Eye' and Motor Performance: A Systematic Review Based on Newell's Constraints-Led Model.

    PubMed

    Rienhoff, Rebecca; Tirp, Judith; Strauß, Bernd; Baker, Joseph; Schorer, Jörg

    2016-04-01

    The quiet eye (final fixation to a specific target prior to movement initiation) is a perceptual skill robustly associated with expertise and superior performance. The benefit of the phenomenon has been demonstrated in a range of sporting tasks. The mechanism(s) underpinning this phenomenon are much-debated and are associated with varying assumptions. This systematic review categorizes previous quiet eye research based on Newell's 1986 model of interacting constraints. Three electronic databases (Web of Science, Scopus, PubMed) were searched from inception until February 2015. Details of relevant studies were also obtained from one literature review and two book chapters. To frame the discussion of research evidence concerning the quiet eye, previous studies were evaluated based on a classification of manipulating performer, environment, and task constraints. Additionally, associative studies (without specific constraints), and interacting constraints (affecting more than one constraint) were considered. This review emphasizes that the quiet eye is beneficial for performing aiming tasks and that Newell's constraints model provides a useful framework for organizing knowledge in this area. Despite the robust research on the value of the quiet eye, several gaps in current knowledge exist regarding the mechanism of the quiet eye effect.

  4. OCT-based crystalline lens topography in accommodating eyes

    PubMed Central

    Pérez-Merino, Pablo; Velasco-Ocana, Miriam; Martinez-Enriquez, Eduardo; Marcos, Susana

    2015-01-01

    Custom Spectral Domain Optical Coherence Tomography (SD-OCT) provided with automatic quantification and distortion correction algorithms was used to measure anterior and posterior crystalline lens surface elevation in accommodating eyes and to evaluate relationships between anterior segment surfaces. Nine young eyes were measured at different accommodative demands. Anterior and posterior lens radii of curvature decreased at a rate of 0.78 ± 0.18 and 0.13 ± 0.07 mm/D, anterior chamber depth decreased at 0.04 ± 0.01 mm/D and lens thickness increased at 0.04 ± 0.01 mm/D with accommodation. Three-dimensional surface elevations were estimated by subtracting best fitting spheres. In the relaxed state, the spherical term accounted for most of the surface irregularity in the anterior lens (47%) and astigmatism (70%) in the posterior lens. However, in accommodated lenses astigmatism was the predominant surface irregularity (90%) in the anterior lens. The RMS of high-order irregularities of the posterior lens surface was statistically significantly higher than that of the anterior lens surface (x2.02, p<0.0001). There was significant negative correlation in vertical coma (Z3−1) and oblique trefoil (Z3−3) between lens surfaces. The astigmatic angle showed high degree of alignment between corneal surfaces, moderate between corneal and anterior lens surface (~27 deg), but differed by ~80 deg between the anterior and posterior lens surfaces (including relative anterior/posterior lens astigmatic angle shifts (10-20 deg). PMID:26713216

  5. Impact of Glaucoma and Dry Eye on Text-Based Searching

    PubMed Central

    Sun, Michelle J.; Rubin, Gary S.; Akpek, Esen K.; Ramulu, Pradeep Y.

    2017-01-01

    Purpose We determine if visual field loss from glaucoma and/or measures of dry eye severity are associated with difficulty searching, as judged by slower search times on a text-based search task. Methods Glaucoma patients with bilateral visual field (VF) loss, patients with clinically significant dry eye, and normally-sighted controls were enrolled from the Wilmer Eye Institute clinics. Subjects searched three Yellow Pages excerpts for a specific phone number, and search time was recorded. Results A total of 50 glaucoma subjects, 40 dry eye subjects, and 45 controls completed study procedures. On average, glaucoma patients exhibited 57% longer search times compared to controls (95% confidence interval [CI], 26%–96%, P < 0.001), and longer search times were noted among subjects with greater VF loss (P < 0.001), worse contrast sensitivity (P < 0.001), and worse visual acuity (P = 0.026). Dry eye subjects demonstrated similar search times compared to controls, though worse Ocular Surface Disease Index (OSDI) vision-related subscores were associated with longer search times (P < 0.01). Search times showed no association with OSDI symptom subscores (P = 0.20) or objective measures of dry eye (P > 0.08 for Schirmer's testing without anesthesia, corneal fluorescein staining, and tear film breakup time). Conclusions Text-based visual search is slower for glaucoma patients with greater levels of VF loss and dry eye patients with greater self-reported visual difficulty, and these difficulties may contribute to decreased quality of life in these groups. Translational Relevance Visual search is impaired in glaucoma and dry eye groups compared to controls, highlighting the need for compensatory strategies and tools to assist individuals in overcoming their deficiencies. PMID:28670502

  6. Impact of Glaucoma and Dry Eye on Text-Based Searching.

    PubMed

    Sun, Michelle J; Rubin, Gary S; Akpek, Esen K; Ramulu, Pradeep Y

    2017-06-01

    We determine if visual field loss from glaucoma and/or measures of dry eye severity are associated with difficulty searching, as judged by slower search times on a text-based search task. Glaucoma patients with bilateral visual field (VF) loss, patients with clinically significant dry eye, and normally-sighted controls were enrolled from the Wilmer Eye Institute clinics. Subjects searched three Yellow Pages excerpts for a specific phone number, and search time was recorded. A total of 50 glaucoma subjects, 40 dry eye subjects, and 45 controls completed study procedures. On average, glaucoma patients exhibited 57% longer search times compared to controls (95% confidence interval [CI], 26%-96%, P < 0.001), and longer search times were noted among subjects with greater VF loss (P < 0.001), worse contrast sensitivity (P < 0.001), and worse visual acuity (P = 0.026). Dry eye subjects demonstrated similar search times compared to controls, though worse Ocular Surface Disease Index (OSDI) vision-related subscores were associated with longer search times (P < 0.01). Search times showed no association with OSDI symptom subscores (P = 0.20) or objective measures of dry eye (P > 0.08 for Schirmer's testing without anesthesia, corneal fluorescein staining, and tear film breakup time). Text-based visual search is slower for glaucoma patients with greater levels of VF loss and dry eye patients with greater self-reported visual difficulty, and these difficulties may contribute to decreased quality of life in these groups. Visual search is impaired in glaucoma and dry eye groups compared to controls, highlighting the need for compensatory strategies and tools to assist individuals in overcoming their deficiencies.

  7. Characterizing the point spread function of retinal OCT devices with a model eye-based phantom.

    PubMed

    Agrawal, Anant; Connors, Megan; Beylin, Alexander; Liang, Chia-Pin; Barton, David; Chen, Yu; Drezek, Rebekah A; Pfefer, T Joshua

    2012-05-01

    We have designed, fabricated, and tested a nanoparticle-embedded phantom (NEP) incorporated into a model eye in order to characterize the point spread function (PSF) of retinal optical coherence tomography (OCT) devices in three dimensions under realistic imaging conditions. The NEP comprises a sparse distribution of highly backscattering silica-gold nanoshells embedded in a transparent UV-curing epoxy. The commercially-available model eye replicates the key optical structures and focusing power of the human eye. We imaged the model eye-NEP combination with a research-grade spectral domain OCT system designed for in vivo retinal imaging and quantified the lateral and axial PSF dimensions across the field of view in the OCT images. We also imaged the model eye-NEP in a clinical OCT system. Subtle features in the PSF and its dimensions were consistent with independent measurements of lateral and axial resolution. This model eye-based phantom can provide retinal OCT device developers and users a means to rapidly, objectively, and consistently assess the PSF, a fundamental imaging performance metric.

  8. Retinal Image-Based Eye-Tracking Using the Tracking Scanning Laser Ophthalmoscope

    NASA Astrophysics Data System (ADS)

    Sheehy, Christy Kathleen

    The tracking scanning laser ophthalmoscope (TSLO) was designed, built and characterized for high-resolution eye-tracking, imaging, and targeted retinal stimulus delivery. Eye-tracking is done via an image-based software program that monitors the image of the retina over time while simultaneously logging the displacements of the eye. Currently, this system is the most accurate, fast and functional eye-tracking system used in a standard ophthalmic instrument. The TSLO has the ability to non-invasively track the eye at 960 Hz (with an accuracy of 0.2 arcminutes or roughly 1 micron) and present stimuli to the retina at the resolution of single cone photoreceptors (0.66 arcminutes, which is roughly 3 microns). The combination of structural imaging and functional testing allows one to begin to more thoroughly understand retinal disease progression, as well probe specific retinal locations in order to test new treatment efficacies. This level of accuracy is unprecedented in the clinic and is crucial when monitoring minute changes in eye motion, structure, and function. Additionally, the system is capable of providing external eye-tracking for other high-resolution imaging systems, such as optical coherence tomography (OCT) and adaptive optics scanning laser ophthalmoscope (AOSLO) systems through the active steering of an imaging beam. This feature allows the imaging raster or stimuli to stay on target during fixational eye motion. This dissertation steps through all of the above-mentioned uses of the TSLO and further elaborates on the optimal design and system test performance capabilities of the system.

  9. Eye-Search: A web-based therapy that improves visual search in hemianopia

    PubMed Central

    Ong, Yean-Hoon; Jacquin-Courtois, Sophie; Gorgoraptis, Nikos; Bays, Paul M; Husain, Masud; Leff, Alexander P

    2015-01-01

    Persisting hemianopia frequently complicates lesions of the posterior cerebral hemispheres, leaving patients impaired on a range of key activities of daily living. Practice-based therapies designed to induce compensatory eye movements can improve hemianopic patients' visual function, but are not readily available. We used a web-based therapy (Eye-Search) that retrains visual search saccades into patients' blind hemifield. A group of 78 suitable hemianopic patients took part. After therapy (800 trials over 11 days), search times into their impaired hemifield improved by an average of 24%. Patients also reported improvements in a subset of visually guided everyday activities, suggesting that Eye-Search therapy affects real-world outcomes. PMID:25642437

  10. Web Camera Based Eye Tracking to Assess Visual Memory on a Visual Paired Comparison Task.

    PubMed

    Bott, Nicholas T; Lange, Alex; Rentz, Dorene; Buffalo, Elizabeth; Clopton, Paul; Zola, Stuart

    2017-01-01

    Background: Web cameras are increasingly part of the standard hardware of most smart devices. Eye movements can often provide a noninvasive "window on the brain," and the recording of eye movements using web cameras is a burgeoning area of research. Objective: This study investigated a novel methodology for administering a visual paired comparison (VPC) decisional task using a web camera.To further assess this method, we examined the correlation between a standard eye-tracking camera automated scoring procedure [obtaining images at 60 frames per second (FPS)] and a manually scored procedure using a built-in laptop web camera (obtaining images at 3 FPS). Methods: This was an observational study of 54 clinically normal older adults.Subjects completed three in-clinic visits with simultaneous recording of eye movements on a VPC decision task by a standard eye tracker camera and a built-in laptop-based web camera. Inter-rater reliability was analyzed using Siegel and Castellan's kappa formula. Pearson correlations were used to investigate the correlation between VPC performance using a standard eye tracker camera and a built-in web camera. Results: Strong associations were observed on VPC mean novelty preference score between the 60 FPS eye tracker and 3 FPS built-in web camera at each of the three visits (r = 0.88-0.92). Inter-rater agreement of web camera scoring at each time point was high (κ = 0.81-0.88). There were strong relationships on VPC mean novelty preference score between 10, 5, and 3 FPS training sets (r = 0.88-0.94). Significantly fewer data quality issues were encountered using the built-in web camera. Conclusions: Human scoring of a VPC decisional task using a built-in laptop web camera correlated strongly with automated scoring of the same task using a standard high frame rate eye tracker camera.While this method is not suitable for eye tracking paradigms requiring the collection and analysis of fine-grained metrics, such as fixation points, built

  11. Web Camera Based Eye Tracking to Assess Visual Memory on a Visual Paired Comparison Task

    PubMed Central

    Bott, Nicholas T.; Lange, Alex; Rentz, Dorene; Buffalo, Elizabeth; Clopton, Paul; Zola, Stuart

    2017-01-01

    Background: Web cameras are increasingly part of the standard hardware of most smart devices. Eye movements can often provide a noninvasive “window on the brain,” and the recording of eye movements using web cameras is a burgeoning area of research. Objective: This study investigated a novel methodology for administering a visual paired comparison (VPC) decisional task using a web camera.To further assess this method, we examined the correlation between a standard eye-tracking camera automated scoring procedure [obtaining images at 60 frames per second (FPS)] and a manually scored procedure using a built-in laptop web camera (obtaining images at 3 FPS). Methods: This was an observational study of 54 clinically normal older adults.Subjects completed three in-clinic visits with simultaneous recording of eye movements on a VPC decision task by a standard eye tracker camera and a built-in laptop-based web camera. Inter-rater reliability was analyzed using Siegel and Castellan's kappa formula. Pearson correlations were used to investigate the correlation between VPC performance using a standard eye tracker camera and a built-in web camera. Results: Strong associations were observed on VPC mean novelty preference score between the 60 FPS eye tracker and 3 FPS built-in web camera at each of the three visits (r = 0.88–0.92). Inter-rater agreement of web camera scoring at each time point was high (κ = 0.81–0.88). There were strong relationships on VPC mean novelty preference score between 10, 5, and 3 FPS training sets (r = 0.88–0.94). Significantly fewer data quality issues were encountered using the built-in web camera. Conclusions: Human scoring of a VPC decisional task using a built-in laptop web camera correlated strongly with automated scoring of the same task using a standard high frame rate eye tracker camera.While this method is not suitable for eye tracking paradigms requiring the collection and analysis of fine-grained metrics, such as fixation points

  12. iDEAS: A web-based system for dry eye assessment.

    PubMed

    Remeseiro, Beatriz; Barreira, Noelia; García-Resúa, Carlos; Lira, Madalena; Giráldez, María J; Yebra-Pimentel, Eva; Penedo, Manuel G

    2016-07-01

    Dry eye disease is a public health problem, whose multifactorial etiology challenges clinicians and researchers making necessary the collaboration between different experts and centers. The evaluation of the interference patterns observed in the tear film lipid layer is a common clinical test used for dry eye diagnosis. However, it is a time-consuming task with a high degree of intra- as well as inter-observer variability, which makes the use of a computer-based analysis system highly desirable. This work introduces iDEAS (Dry Eye Assessment System), a web-based application to support dry eye diagnosis. iDEAS provides a framework for eye care experts to collaboratively work using image-based services in a distributed environment. It is composed of three main components: the web client for user interaction, the web application server for request processing, and the service module for image analysis. Specifically, this manuscript presents two automatic services: tear film classification, which classifies an image into one interference pattern; and tear film map, which illustrates the distribution of the patterns over the entire tear film. iDEAS has been evaluated by specialists from different institutions to test its performance. Both services have been evaluated in terms of a set of performance metrics using the annotations of different experts. Note that the processing time of both services has been also measured for efficiency purposes. iDEAS is a web-based application which provides a fast, reliable environment for dry eye assessment. The system allows practitioners to share images, clinical information and automatic assessments between remote computers. Additionally, it save time for experts, diminish the inter-expert variability and can be used in both clinical and research settings. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Effect of glaucoma on eye movement patterns and laboratory-based hazard detection ability.

    PubMed

    Lee, Samantha Sze-Yee; Black, Alex A; Wood, Joanne M

    2017-01-01

    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. 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. 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). 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.

  14. Improved eye- and skin-color prediction based on 8 SNPs.

    PubMed

    Hart, Katie L; Kimura, Shey L; Mushailov, Vladimir; Budimlija, Zoran M; Prinz, Mechthild; Wurmbach, Elisa

    2013-06-01

    To improve the 7-plex system to predict eye and skin color by increasing precision and detailed phenotypic descriptions. Analysis of an eighth single nucleotide polymorphism (SNP), rs12896399 (SLC24A4), showed a statistically significant association with human eye color (P=0.007) but a rather poor strength of agreement (κ=0.063). This SNP was added to the 7-plex system (rs12913832 at HERC2, rs1545397 at OCA2, rs16891982 at SLC45A2, rs1426654 at SLC24A5, rs885479 at MC1R, rs6119471 at ASIP, and rs12203592 at IRF4). Further, the instruction guidelines on the interpretation of genotypes were changed to create a new 8-plex system. This was based on the analysis of an 803-sample training set of various populations. The newly developed 8-plex system can predict the eye colors brown, green, and blue, and skin colors light, not dark, and not light. It is superior to the 7-plex system with its additional ability to predict blue eye and light skin color. The 8-plex system was tested on an additional 212 samples, the test set. Analysis showed that the number of positive descriptions for eye colors as being brown, green, or blue increased significantly (P=6.98e-15, z-score: -7.786). The error rate for eye-color prediction was low, at approximately 5%, while the skin color prediction showed no error in the test set (1% in training set). We can conclude that the new 8-plex system for the prediction of eye and skin color substantially enhances its former version.

  15. Spatial Resolution Effects of Remote Sensing Informed Soil Nutrient Models Based on Landsat 8, RapidEye, WorldView-2 and GeoEye-1 Images

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Grunwald, S.; Smith, S. E.; Abd-Elrahman, A.; Clingensmith, C. M.; Wani, S.

    2015-12-01

    Soil nutrient storage is essential and important to maintain food security and soil security in smallholder farm settings. The objective of this research was to analyze the spatial resolution effects of different remote sensing images on soil prediction models in Kothapally, India. We utilized Bayesian kriging (BK) to characterize the spatial pattern of total nitrogen (TN) and exchangeable potassium (Kex) in the topsoil (0-15 cm) at different spatial resolutions by incorporating spectral indices from Landsat 8 (30m), RapidEye (5m) and WorldView-2/GeoEye-1 images (2m). The band ratio of red to green, red to blue and green to blue, Crust Index and Atmospherically Resistant Vegetation Index from multiple images generally had high linear correlations with TN and Kex. The BK model of TN based on WorldView-2 and GeoEye-1 attained the highest model fit (R2=0.41) and lowest prediction error (RMSE=171.35 mg kg-1) compared with the BK models of TN based on Landsat 8 (R2=0.30; RMSE=182.26 mg kg-1) and RapidEye (R2=0.28; RMSE=183.52 mg kg-1). The BK model of Kex based on Landsat 8 had the highest model fit (R2=0.55) and the second lowest prediction error (RMSE=79.57 mg kg-1) compared with the BK models of Kex based on WorldView-2 and GeoEye-1 (R2=0.52; RMSE=79.42 mg kg-1) and RapidEye (R2=0.47; RMSE=83.91 mg kg-1). The lowest prediction fit and highest prediction error of soil TN and Kex models based on RapidEye suggest that the effect of fine spatial remote sensing spectral data inputs do not always lead to an increase of model fit. Soil maps based on WorldView-2 and GeoEye-1 have significant advantages in characterizing the variation of soil TN and Kex spatial pattern in smallholder farm settings compared with coarser maps. This research suggests that Digital Soil Mapping utilizing remote sensing spectral data from WorldView-2 and GeoEye-1 has high potential to be widely applied in smallholder farm settings and help smallholder farmers manage their soils and attain soil

  16. 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.

  17. Video-Based Eye Tracking in Sex Research: A Systematic Literature Review.

    PubMed

    Wenzlaff, Frederike; Briken, Peer; Dekker, Arne

    2015-12-21

    Although eye tracking has been used for decades, it has gained popularity in the area of sex research only recently. The aim of this article is to examine the potential merits of eye tracking for this field. We present a systematic review of the current use of video-based eye-tracking technology in this area, evaluate the findings, and identify future research opportunities. A total of 34 relevant studies published between 2006 and 2014 were identified for inclusion by means of online databases and other methods. We grouped them into three main areas of research: body perception and attractiveness, forensic research, and sexual orientation. Despite the methodological and theoretical differences across the studies, eye tracking has been shown to be a promising tool for sex research. The article suggests there is much potential for further studies to employ this technique because it is noninvasive and yet still allows for the assessment of both conscious and unconscious perceptional processes. Furthermore, eye tracking can be implemented in investigations of various theoretical backgrounds, ranging from biology to the social sciences.

  18. Removing eye blink artefacts from EEG-A single-channel physiology-based method.

    PubMed

    Zhang, Shenghuan; McIntosh, Julia; Shadli, Shabah M; Neo, Phoebe S-H; Huang, Zhiyi; McNaughton, Neil

    2017-11-01

    EEG signals are often contaminated with artefacts, particularly with large signals generated by eye blinks. Deletion of artefact can lose valuable data. Current methods of removing the eye blink component to leave residual EEG, such as blind source component removal, require multichannel recording, are computationally intensive, and can alter the original EEG signal. Here we describe a novel single-channel method using a model based on the ballistic physiological components of the eye blink. This removes the blink component, leaving uncontaminated EEG largely unchanged. Processing time allows its use in real-time applications such as neurofeedback training. Blink removal had a success rate of over 90% recovered variance of original EEG when removing synthesised eye blink components. Fronto-lateral sites were poorer (∼80%) than most other sites (92-96%), with poor fronto-polar results (67%). When compared with three popular independent component analysis (ICA) methods, our method was only slightly (1%) better at frontal midline sites but significantly (>20%) better at lateral sites with an overall advantage of ∼10%. With few recording channels and real-time processing, our method shows clear advantages over ICA for removing eye blinks. It should be particularly suited for use in portable brain-computer-interfaces and in neurofeedback training. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Online Learners' Reading Ability Detection Based on Eye-Tracking Sensors.

    PubMed

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S W

    2016-09-10

    The detection of university online learners' reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners' pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner's reading ability.

  20. Characterization of gamma irradiated petrolatum eye ointment base by headspace-gas chromatography-mass spectrometry.

    PubMed

    Hong, Lan; Altorfer, Hans

    2002-06-20

    The effects of gamma irradiation on petrolatum eye ointment base (EOB) and its ingredients (white petrolatum, liquid paraffin, and wool fat) were studied at different irradiation doses. Forty-one volatile radiolysis products were detected and identified by a combined system of headspace-gas chromatography-mass spectrometry (HS-GC-MS). The characteristics of the radiolysis products and the degradation pathway were discussed in each case, respectively. GC method demonstrates that the component distribution patterns of eye ointment as well as its individual ingredients have no differences before and after gamma irradiation. The influence of gamma treatment on EOB was quantitatively determined at 15, 25 and 50 kGy. The concentrations of the radiolysis products increase linearly with increasing doses. Both qualitative and quantitative data show that irradiated eye ointment is safe for human use.

  1. Online Learners’ Reading Ability Detection Based on Eye-Tracking Sensors

    PubMed Central

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S. W.

    2016-01-01

    The detection of university online learners’ reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners’ pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner’s reading ability. PMID:27626418

  2. Prior Knowledge and Online Inquiry-Based Science Reading: Evidence from Eye Tracking

    ERIC Educational Resources Information Center

    Ho, Hsin Ning Jessie; Tsai, Meng-Jung; Wang, Ching-Yeh; Tsai, Chin-Chung

    2014-01-01

    This study employed eye-tracking technology to examine how students with different levels of prior knowledge process text and data diagrams when reading a web-based scientific report. Students' visual behaviors were tracked and recorded when they read a report demonstrating the relationship between the greenhouse effect and global climate…

  3. Prior Knowledge and Online Inquiry-Based Science Reading: Evidence from Eye Tracking

    ERIC Educational Resources Information Center

    Ho, Hsin Ning Jessie; Tsai, Meng-Jung; Wang, Ching-Yeh; Tsai, Chin-Chung

    2014-01-01

    This study employed eye-tracking technology to examine how students with different levels of prior knowledge process text and data diagrams when reading a web-based scientific report. Students' visual behaviors were tracked and recorded when they read a report demonstrating the relationship between the greenhouse effect and global climate…

  4. Clinical effect of four different ointment bases on healthy cat eyes.

    PubMed

    Eördögh, Réka; Schwendenwein, Ilse; Tichy, Alexander; Loncaric, Igor; Nell, Barbara

    2016-07-01

    To describe the effects of long-term treatment with four different eye ointment bases (OBs) in cats. Ten healthy cats. The study was performed in two periods. Four different OBs were tested. Hundred grams of OB contained the following: OB-A: 35.17 g liquid paraffin (lp), 64.83 g white petrolatum (wp); OB-B: 10.03 g lp, 84.95 g wp 5.02 g lanolin; OB-C: 18.34 g lp, 51.40 g wp, 25.00 mg KH2 PO4 , 57.00 mg K2 HPO4 , 18.90 g eucerinum anhydricum, 11.28 g water for injections; and OB-D: 70 g unguentum lanalcoli, 20 g lp, 10 g aqua conservans. One eye was treated, and the other served as a negative control. Cats received the OBs TID for 28 days. The two study periods were separated by a 4-month washout phase. Samples for conjunctival impression cytology, swabs for bacteriologic and mycologic examination, and cytobrush samples for FHV-1 and Chlamydophila felis PCR detection were obtained. Both eyes were examined daily. Severity of ocular symptoms was scored using a modified Draize eye irritation test. A total of five eyes were treated with OB-A, five with OB-B, four with OB-C, and five with OB-D. Treated eyes had significantly higher clinical scores. Eyes receiving OB-A had the highest overall clinical score. The results of bacteriologic and mycologic examination concur with the previously published data. All samples tested were negative for FHV-1 and Chlamydophila felis. There was no significant difference between treated and control eyes upon cytological examination. The application of OBs resulted in clinical symptoms in treated eyes. The long-term use of ointments is not well tolerated in cats and may lead to ocular irritation. © 2015 American College of Veterinary Ophthalmologists.

  5. Automatic system for 3D reconstruction of the chick eye based on digital photographs.

    PubMed

    Wong, Alexander; Genest, Reno; Chandrashekar, Naveen; Choh, Vivian; Irving, Elizabeth L

    2012-01-01

    The geometry of anatomical specimens is very complex and accurate 3D reconstruction is important for morphological studies, finite element analysis (FEA) and rapid prototyping. Although magnetic resonance imaging, computed tomography and laser scanners can be used for reconstructing biological structures, the cost of the equipment is fairly high and specialised technicians are required to operate the equipment, making such approaches limiting in terms of accessibility. In this paper, a novel automatic system for 3D surface reconstruction of the chick eye from digital photographs of a serially sectioned specimen is presented as a potential cost-effective and practical alternative. The system is designed to allow for automatic detection of the external surface of the chick eye. Automatic alignment of the photographs is performed using a combination of coloured markers and an algorithm based on complex phase order likelihood that is robust to noise and illumination variations. Automatic segmentation of the external boundaries of the eye from the aligned photographs is performed using a novel level-set segmentation approach based on a complex phase order energy functional. The extracted boundaries are sampled to construct a 3D point cloud, and a combination of Delaunay triangulation and subdivision surfaces is employed to construct the final triangular mesh. Experimental results using digital photographs of the chick eye show that the proposed system is capable of producing accurate 3D reconstructions of the external surface of the eye. The 3D model geometry is similar to a real chick eye and could be used for morphological studies and FEA.

  6. Bird's-eye view on noise-based logic

    NASA Astrophysics Data System (ADS)

    Kish, Laszlo B.; Granqvist, Claes G.; Horvath, Tamas; Klappenecker, Andreas; Wen, He; Bezrukov, Sergey M.

    2014-09-01

    Noise-based logic is a practically deterministic logic scheme inspired by the randomness of neural spikes and uses a system of uncorrelated stochastic processes and their superposition to represent the logic state. We briefly discuss various questions such as (i) What does practical determinism mean? (ii) Is noise-based logic a Turing machine? (iii) Is there hope to beat (the dreams of) quantum computation by a classical physical noise-based processor, and what are the minimum hardware requirements for that? Finally, (iv) we address the problem of random number generators and show that the common belief that quantum number generators are superior to classical (thermal) noise-based generators is nothing but a myth.

  7. Smooth pursuit detection in binocular eye-tracking data with automatic video-based performance evaluation.

    PubMed

    Larsson, Linnéa; Nyström, Marcus; Ardö, Håkan; Åström, Kalle; Stridh, Martin

    2016-12-01

    An increasing number of researchers record binocular eye-tracking signals from participants viewing moving stimuli, but the majority of event-detection algorithms are monocular and do not consider smooth pursuit movements. The purposes of the present study are to develop an algorithm that discriminates between fixations and smooth pursuit movements in binocular eye-tracking signals and to evaluate its performance using an automated video-based strategy. The proposed algorithm uses a clustering approach that takes both spatial and temporal aspects of the binocular eye-tracking signal into account, and is evaluated using a novel video-based evaluation strategy based on automatically detected moving objects in the video stimuli. The binocular algorithm detects 98% of fixations in image stimuli compared to 95% when only one eye is used, while for video stimuli, both the binocular and monocular algorithms detect around 40% of smooth pursuit movements. The present article shows that using binocular information for discrimination of fixations and smooth pursuit movements is advantageous in static stimuli, without impairing the algorithm's ability to detect smooth pursuit movements in video and moving-dot stimuli. With an automated evaluation strategy, time-consuming manual annotations are avoided and a larger amount of data can be used in the evaluation process.

  8. An integrated Mach-Zehnder modulator bias controller based on eye-amplitude monitoring

    NASA Astrophysics Data System (ADS)

    Kim, Min-Hyeong; Jung, Hyun-Yong; Zimmermann, Lars; Choi, Woo-Young

    2016-03-01

    A novel integrated Mach-Zehnder modulator (MZM) bias controller based on eye-amplitude monitoring is demonstrated in IHP's 0.25-μm BiCMOS technology. The bias controller monitors the MZM output light, automatically moves the MZM bias voltage to the optimal value that produces the largest eye amplitude, and maintains it there even if the MZM transfer characteristics change due to thermal drift. The controller is based on the feedback loop consisting of Si photodetector, trans-impedance amplifier, rectifier, square amplifier, track-and-hold circuit, comparator, polarity changer, and charge-pump, all of which are monolithically integrated. The area of the controller is 0.083-mm2 and it consumes 92.5-mW. Our bias controller shows successful operation for a commercially-available 850-nm LiNbO3 MZM modulated with 3-Gbps PRBS data by maintaining a very clean eye for at least 30 minutes. Without the controller, the eye for the same MZM modulation becomes completely closed due to thermal drift. The data rate is limited by the Si PD integrated in the controller not by the controller architecture. Since our controller is based on the Si BiCMOS technology which can also provide integrated Si photonics devices on the same Si, it has a great potential for realizing a Si MZM with an integrated bias controller, which should fully demonstrate the advantage of electronic-photonic integrated circuit technology.

  9. Gaze Estimation for Off-Angle Iris Recognition Based on the Biometric Eye Model

    SciTech Connect

    Karakaya, Mahmut; Barstow, Del R; Santos-Villalobos, Hector J; Thompson, Joseph W; Bolme, David S; Boehnen, Chris Bensing

    2013-01-01

    Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ANONYMIZED biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

  10. Multi-User Identification-Based Eye-Tracking Algorithm Using Position Estimation.

    PubMed

    Kang, Suk-Ju

    2016-12-27

    This paper proposes a new multi-user eye-tracking algorithm using position estimation. Conventional eye-tracking algorithms are typically suitable only for a single user, and thereby cannot be used for a multi-user system. Even though they can be used to track the eyes of multiple users, their detection accuracy is low and they cannot identify multiple users individually. The proposed algorithm solves these problems and enhances the detection accuracy. Specifically, the proposed algorithm adopts a classifier to detect faces for the red, green, and blue (RGB) and depth images. Then, it calculates features based on the histogram of the oriented gradient for the detected facial region to identify multiple users, and selects the template that best matches the users from a pre-determined face database. Finally, the proposed algorithm extracts the final eye positions based on anatomical proportions. Simulation results show that the proposed algorithm improved the average F₁ score by up to 0.490, compared with benchmark algorithms.

  11. Research on the image fusion and target extraction based on bionic compound eye system

    NASA Astrophysics Data System (ADS)

    Zhang, Shaowei; Hao, Qun; Song, Yong; Wang, Zihan; Zhang, Kaiyu; Zhang, Shiyu

    2015-08-01

    People attach more and more importance to bionic compound eye due to its advantages such as small volume, large field of view and sensitivity to high-speed moving objects. Small field of view and large volume are the disadvantages of traditional image sensor and in order to avoid these defects, this paper intends to build a set of compound eye system based on insect compound eye structure and visual processing mechanism. In the center of this system is the primary sensor which has high resolution ratio. The primary sensor is surrounded by the other six sensors which have low resolution ratio. Based on this system, this paper will study the target image fusion and extraction method by using plane compound eye structure. This paper designs a control module which can combine the distinguishing features of high resolution image with local features of low resolution image so as to conduct target detection, recognition and location. Compared with traditional ways, the way of high resolution in the center and low resolution around makes this system own the advantages of high resolution and large field of view and enables the system to detect the object quickly and recognize the object accurately.

  12. Multi-User Identification-Based Eye-Tracking Algorithm Using Position Estimation

    PubMed Central

    Kang, Suk-Ju

    2016-01-01

    This paper proposes a new multi-user eye-tracking algorithm using position estimation. Conventional eye-tracking algorithms are typically suitable only for a single user, and thereby cannot be used for a multi-user system. Even though they can be used to track the eyes of multiple users, their detection accuracy is low and they cannot identify multiple users individually. The proposed algorithm solves these problems and enhances the detection accuracy. Specifically, the proposed algorithm adopts a classifier to detect faces for the red, green, and blue (RGB) and depth images. Then, it calculates features based on the histogram of the oriented gradient for the detected facial region to identify multiple users, and selects the template that best matches the users from a pre-determined face database. Finally, the proposed algorithm extracts the final eye positions based on anatomical proportions. Simulation results show that the proposed algorithm improved the average F1 score by up to 0.490, compared with benchmark algorithms. PMID:28035979

  13. Gaze estimation for off-angle iris recognition based on the biometric eye model

    NASA Astrophysics Data System (ADS)

    Karakaya, Mahmut; Barstow, Del; Santos-Villalobos, Hector; Thompson, Joseph; Bolme, David; Boehnen, Christopher

    2013-05-01

    Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ORNL biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

  14. Computational Model-Based Prediction of Human Episodic Memory Performance Based on Eye Movements

    NASA Astrophysics Data System (ADS)

    Sato, Naoyuki; Yamaguchi, Yoko

    Subjects' episodic memory performance is not simply reflected by eye movements. We use a ‘theta phase coding’ model of the hippocampus to predict subjects' memory performance from their eye movements. Results demonstrate the ability of the model to predict subjects' memory performance. These studies provide a novel approach to computational modeling in the human-machine interface.

  15. From neural-based object recognition toward microelectronic eyes

    NASA Technical Reports Server (NTRS)

    Sheu, Bing J.; Bang, Sa Hyun

    1994-01-01

    Engineering neural network systems are best known for their abilities to adapt to the changing characteristics of the surrounding environment by adjusting system parameter values during the learning process. Rapid advances in analog current-mode design techniques have made possible the implementation of major neural network functions in custom VLSI chips. An electrically programmable analog synapse cell with large dynamic range can be realized in a compact silicon area. New designs of the synapse cells, neurons, and analog processor are presented. A synapse cell based on Gilbert multiplier structure can perform the linear multiplication for back-propagation networks. A double differential-pair synapse cell can perform the Gaussian function for radial-basis network. The synapse cells can be biased in the strong inversion region for high-speed operation or biased in the subthreshold region for low-power operation. The voltage gain of the sigmoid-function neurons is externally adjustable which greatly facilitates the search of optimal solutions in certain networks. Various building blocks can be intelligently connected to form useful industrial applications. Efficient data communication is a key system-level design issue for large-scale networks. We also present analog neural processors based on perceptron architecture and Hopfield network for communication applications. Biologically inspired neural networks have played an important role towards the creation of powerful intelligent machines. Accuracy, limitations, and prospects of analog current-mode design of the biologically inspired vision processing chips and cellular neural network chips are key design issues.

  16. Online webcam-based eye tracking in cognitive science: A first look.

    PubMed

    Semmelmann, Kilian; Weigelt, Sarah

    2017-06-07

    Online experimentation is emerging in many areas of cognitive psychology as a viable alternative or supplement to classical in-lab experimentation. While performance- and reaction-time-based paradigms are covered in recent studies, one instrument of cognitive psychology has not received much attention up to now: eye tracking. In this study, we used JavaScript-based eye tracking algorithms recently made available by Papoutsaki et al. (International Joint Conference on Artificial Intelligence, 2016) together with consumer-grade webcams to investigate the potential of online eye tracking to benefit from the common advantages of online data conduction. We compared three in-lab conducted tasks (fixation, pursuit, and free viewing) with online-acquired data to analyze the spatial precision in the first two, and replicability of well-known gazing patterns in the third task. Our results indicate that in-lab data exhibit an offset of about 172 px (15% of screen size, 3.94° visual angle) in the fixation task, while online data is slightly less accurate (18% of screen size, 207 px), and shows higher variance. The same results were found for the pursuit task with a constant offset during the stimulus movement (211 px in-lab, 216 px online). In the free-viewing task, we were able to replicate the high attention attribution to eyes (28.25%) compared to other key regions like the nose (9.71%) and mouth (4.00%). Overall, we found web technology-based eye tracking to be suitable for all three tasks and are confident that the required hard- and software will be improved continuously for even more sophisticated experimental paradigms in all of cognitive psychology.

  17. Examining the Effects of Chromatic Aberration, Object Distance, and Eye Shape on Image-Formation in the Mirror-Based Eyes of the Bay Scallop Argopecten irradians.

    PubMed

    Speiser, Daniel I; Gagnon, Yakir Luc; Chhetri, Raghav K; Oldenburg, Amy L; Johnsen, Sönke

    2016-11-01

    The eyes of scallops form images using a concave spherical mirror and contain two separate retinas, one layered on top of the other. Behavioral and electrophysiological studies indicate that the images formed by these eyes have angular resolutions of about 2°. Based on previous ray-tracing models, it has been thought that the more distal of the two retinas lies near the focal point of the mirror and that the proximal retina, positioned closer to the mirror at the back of the eye, receives light that is out-of-focus. Here, we propose three mechanisms through which both retinas may receive focused light: (1) chromatic aberration produced by the lens may cause the focal points for longer and shorter wavelengths to fall near the distal and proximal retinas, respectively; (2) focused light from near and far objects may fall on the distal and proximal retinas, respectively; and (3) the eyes of scallops may be dynamic structures that change shape to determine which retina receives focused light. To test our hypotheses, we used optical coherence tomography (OCT), a method of near-infrared optical depth-ranging, to acquire virtual cross-sections of live, intact eyes from the bay scallop Argopecten irradians Next, we used a custom-built ray-tracing model to estimate the qualities of the images that fall on an eye's distal and proximal retinas as functions of the wavelengths of light entering the eye (400-700 nm), object distances (0.01-1 m), and the overall shape of the eye. When we assume 550 nm wavelength light and object distances greater than 0.01 m, our model predicts that the angular resolutions of the distal and proximal retinas are 2° and 7°, respectively. Our model also predicts that neither chromatic aberration nor differences in object distance lead to focused light falling on the distal and proximal retinas simultaneously. However, if scallops can manipulate the shapes of their eyes, perhaps through muscle contractions, we speculate that they may be able

  18. Eye Cancer

    MedlinePlus

    ... Cancer > Eye Cancer > Eye Cancer: Overview Request Permissions Eye Cancer: Overview Approved by the Cancer.Net Editorial ... trained to treat intraocular cancer. Parts of the eye The eye is the organ that collects light ...

  19. Eye Infections

    MedlinePlus

    Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are Conjunctivitis - also known as pinkeye. Conjunctivitis is ...

  20. Image-Based Visual Tracking Control of Hand-Eye Robot for Moving Target Object

    NASA Astrophysics Data System (ADS)

    Ito, Masahide; Shibata, Masaaki

    In this paper, we propose an image-based visual tracking control method of a hand-eye robot for a moving target object. The hand-eye robot is constructed from a three-DoF planar manipulator and a single CCD camera that is mounted on the end-effector. This robot is a typical example of an eye-in-hand system with a single camera. The control objective is to keep the target object around the center of the image plane. In many conventional visual servo methods, it is assumed that the target object is static. Consequently, the visual tracking delay arises in the case of a moving target object. Although we have already proposed a non-delayed visual tracking control method for a moving target object, this method is developed only for a stereo vision robot with two CCD cameras. Therefore, this paper provides such a visual tracking control method for the hand-eye robot. The validity of our control method is evaluated by an experiment.

  1. NGS-based Molecular diagnosis of 105 eyeGENE(®) probands with Retinitis Pigmentosa.

    PubMed

    Ge, Zhongqi; Bowles, Kristen; Goetz, Kerry; Scholl, Hendrik P N; Wang, Feng; Wang, Xinjing; Xu, Shan; Wang, Keqing; Wang, Hui; Chen, Rui

    2015-12-15

    The National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE(®)) was established in an effort to facilitate basic and clinical research of human inherited eye disease. In order to provide high quality genetic testing to eyeGENE(®)'s enrolled patients which potentially aids clinical diagnosis and disease treatment, we carried out a pilot study and performed Next-generation sequencing (NGS) based molecular diagnosis for 105 Retinitis Pigmentosa (RP) patients randomly selected from the network. A custom capture panel was designed, which incorporated 195 known retinal disease genes, including 61 known RP genes. As a result, disease-causing mutations were identified in 52 out of 105 probands (solving rate of 49.5%). A total of 82 mutations were identified, and 48 of them were novel. Interestingly, for three probands the molecular diagnosis was inconsistent with the initial clinical diagnosis, while for five probands the molecular information suggested a different inheritance model other than that assigned by the physician. In conclusion, our study demonstrated that NGS target sequencing is efficient and sufficiently precise for molecular diagnosis of a highly heterogeneous patient cohort from eyeGENE(®).

  2. 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.

  3. A noninvasive eye fixation and computer-aided eye monitoring system for linear accelerator-based stereotactic radiotherapy of uveal melanoma.

    PubMed

    Bogner, Joachim; Petersch, Bernhard; Georg, Dietmar; Dieckmann, Karin; Zehetmayer, Martin; Pötter, Richard

    2003-07-15

    To introduce a noninvasive eye fixation and computer-aided eye monitoring system for linear accelerator-based stereotactic radiotherapy for uveal melanoma. At the Department of Radiotherapy and Radiobiology, University of Vienna, stereotactic radiotherapy is offered to patients with uveal melanoma considered unsuitable for (106)Ru brachytherapy or local resection. For the present feasibility study, 8 patients were carefully selected according to their ability to fixate a small light source with the diseased eye and whether they had a rather small head to meet the limited geometric space available. A polymethyl methacrylate tube was attached to a stereotactic mask system in craniocaudal orientation supporting a 45 degrees mirror, which was placed in front of the diseased eye. At the other end of the tube, the patient was given a small fixation light, and a small camera was positioned beneath, which was shielded for use during MRI. A computer interface calculated and visualized the spatial difference of the actual and a given reference pupil position, which was defined before CT scanning, during the MRI sequences, and during treatment delivery at the linear accelerator. The described system can be attached to a conventional stereotactic mask system with minor modifications. Because of the large distance between the eye and the fixation light, the optical fixation system was well tolerated by all patients, and a stable position of the eye was obtained. The camera system can be used during CT and MRI without interference. Absorption of the 6-MV photon beam by the mirror and the polymethyl methacrylate tube was negligible. The computer interface designed to determine the pupil position uses an image-processing algorithm that correlates a template of the reference image with the actual image of the eye. Provided sufficient illumination of the pupil, the correlation function showed a pronounced minimum at the reference position. The precision of the algorithm was tested

  4. Prevalence of Second-Eye Cataract Surgery and Time Interval after First-Eye Surgery in Iran: A Clinic-Based Study

    PubMed Central

    Katibeh, Marzieh; Moein, Hamid-Reza; Yaseri, Mehdi; Sehat, Mojtaba; Eskandari, Armen; Ziaei, Hossein

    2013-01-01

    Purpose: To determine the prevalence of second-eye senile cataract surgery (SECS) as a proportion of all senile cataract surgeries and the trend in the interval between first and second cataract operations in a main referral and academic eye hospital. Materials and Methods: In this cross-sectional study, a list of patients who underwent senile cataract surgery over four consecutive years (2006-2009) was retrieved from hospital computer-based records as the sampling frame. With a systematic random method, 15% of records were selected (1,585 out of 10,517 records). Results: First- and second-eye operations were performed in 1,139 (71.9%; 95% confidence interval [CI], 69.5-74.1) and 446 eyes (28.1%; 95% CI, 25.9-30.35), respectively. The proportion of SECS procedures increased from 24.3% in 2006 to 33.4% in 2009 (P = 0.017). The median (interquartile range) interval between the two operations was 9 (4-24) months, which remained stable during the study period. The SECS rate was 10.4% higher (P = 0.01) and the time interval was 13 months shorter (P = 0.007) in patients who underwent phacoemulsification than extracapsular cataract extraction. Conclusion: The number of cataract operations in this tertiary eye care setting increased 1.5 fold over the study period. The proportion of second-eye operations also rose from 1/4 to 1/3 during the same time. PMID:23580856

  5. Design and baseline characteristics of a population-based study of eye disease in southern Chinese people: the Dongguan Eye Study.

    PubMed

    Meng, Qianli; Cui, Ying; Zhang, Min; Zhang, Lixin; Zhang, Liang; Zhang, Jinxin; Kuang, Jian; Liu, Qingyang; Zheng, Yang; Luo, Zhongling; Liu, Huikun; Zhu, Guoping; Cai, Jingjing; Zhang, Guanrong; Wen, Xingxuan; Guo, Haike

    2016-04-01

    To describe the study design, methodology and baseline characteristics of the Dongguan Eye Study. Population-based, cross-sectional study A total of 8952 rural-dwelling residents aged 40 years or older in Hengli, Dongguan. The Dongguan Eye Study was conducted from September 2011 to February 2012. The interview covered demographic data, socio-economic status and health- and vision-related quality of life. Physical measurements included height, weight, waist and hip circumference, heart rate and blood pressure. Laboratory tests included fasting blood glucose, haemoglobin A1c, oral glucose tolerance, serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and uric acid. Ophthalmic examinations included visual acuity and autorefraction testing, intraocular pressure measurement, slit-lamp examination, ocular biometry, gonioscopy, fundus photography, retinal nerve fibre layer imaging and visual field testing. Prevalence and risk factors for visual impairment, blindness, eye diseases and their associations with systemic medical indicators or health-related lifestyles, as well as epidemiological data on diabetic subjects. Methodology, response rates and baseline characteristics are presented. Of the 11 357 individuals eligible for the Dongguan Eye Study, 8952 (78.82%) subjects participated. All participants were self-identified Han Chinese. The average age was 54.0 years, 59.9% were female, 48.4% were farmers and 77.2% had elementary or junior middle school educational levels. The average body mass index and waist-hip ratio were 24.6 ± 3.9 kg/m(2) and 0.9 ± 0.2. Data from the Dongguan Eye Study provide information concerning the prevalence, risk factors and impacts of eye diseases in rural residents undergoing urbanization in southern China. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  6. Image-Based Grouping during Binocular Rivalry Is Dictated by Eye-Of-Origin

    PubMed Central

    Stuit, Sjoerd M.; Paffen, Chris L. E.; van der Smagt, Maarten J.; Verstraten, Frans A. J.

    2014-01-01

    Prolonged viewing of dichoptically presented images with different content results in perceptual alternations known as binocular rivalry. This phenomenon is thought to be the result of competition at a local level, where local rivalry zones interact to give rise to a single, global dominant percept. Certain perceived combinations that result from this local competition are known to last longer than others, which is referred to as grouping during binocular rivalry. In recent years, the phenomenon has been suggested to be the result of competition at both eye- and image-based processing levels, although the exact contribution from each level remains elusive. Here we use a paradigm designed specifically to quantify the contribution of eye- and image-based processing to grouping during rivalry. In this paradigm we used sine-wave gratings as well as upright and inverted faces, with and without binocular disparity-based occlusion. These stimuli and conditions were used because they are known to result in processing at different stages throughout the visual processing hierarchy. Specifically, more complex images were included in order to maximize the potential contribution of image-based grouping. In spite of this, our results show that increasing image complexity did not lead to an increase in the contribution of image-based processing to grouping during rivalry. In fact, the results show that grouping was primarily affected by the eye-of-origin of the image parts, irrespective of stimulus type. We suggest that image content affects grouping during binocular rivalry at low-level processing stages, where it is intertwined with eye-of-origin information. PMID:24987847

  7. Position and momentum bases on the sphere for the monochromatic Maxwell fish-eye

    NASA Astrophysics Data System (ADS)

    Salto-Alegre, Cristina; Wolf, Kurt Bernardo

    2015-04-01

    The sphere is well understood manifold, as is the basis of spherical harmonics for functions thereof. A stereographic projection of the sphere realizes the Maxwell fish-eye, an optical medium whose refractive index distribution is such that light rays travel in circles. Definite angular momentum on the sphere corresponds with monochromatic light in the fish-eye. A contraction of these manifolds (as the radius of the sphere grows without bound) results in a plane medium of wave functions subject to the Helmholtz equation. In the latter, there is the continuous basis of ‘momenta’ (plane waves) and a denumerably infinite basis of ‘positions’ and ‘normal derivatives’ (Bessel ∼ J0(x) and ∼ J1(x)/x functions) for the Hilbert space of these wavefields. We present the pre-contraction of these bases to the finite-dimensional systems of fish-eye medium and the sphere. The ‘momentum’ basis is a subset of Sherman-Volobuyev functions; in this paper we propose new ‘position’ and ‘normal derivative’ bases for this finite system. The bases are not orthogonal, so their measure is non-local, and here we find their dual bases.

  8. Eye movement-based measures of development of spatial contrast sensitivity in infants.

    PubMed

    Hainline, L; Abramov, I

    1997-10-01

    This study presents spatial contrast sensitivity functions from 66 infants ranging in age from 12 to 146 days. Functions were derived using a behavioral method based on eye movements; in this method, the subject viewed drifting sinusoidal gratings while an experimenter, who did not know the direction of stimulus drift, voted on that direction based only on the record of the subject's eye movements. Results show that there is a marked increase in contrast sensitivity across age, as well as a modest shift of the peak of the function and of the acuity limit to higher spatial frequencies. However, when normalized with respect to peak frequency and peak sensitivity, the functions at all ages have the same general shape and can be fit with a standard template curve used to describe contrast sensitivity in the adult visual system; that is, even the youngest infants clearly show a drop in sensitivity at frequencies below the peaks of their functions.

  9. 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

  10. Prevalence and Factors Associated With Second Eye Cataract Surgery and the Trend in the Time Interval Between the Two Eye Surgeries Based on the Malaysian National Eye Database.

    PubMed

    Ho, Shu Fen; Adnan, Tassha Hilda Bin; Goh, Pik Pin

    2017-01-01

    To study the prevalence of second eye cataract surgery (SECS), trend in time interval between subsequent surgeries over the years, and factors associated with SECS utilization among patients who underwent cataract surgeries in the Ministry of Health (MOH), Malaysia. Secondary cross-sectional analysis of the Malaysian National Eye Database (NED) data. The Malaysian Cataract Surgery Registry collected data on patients who had cataract surgery from 2002-2004 and 2007-2012. Data collected included demography, operative events, time interval between 2 surgeries, and postoperative visual outcomes. Descriptive analysis was performed. Total surgeries increased from 11,954 in 2002 to 30,265 in 2012 with a proportionate increase in SECS (30.7% in 2002 to 34.3% in 2012). Poor vision (<6/12) was reduced from 81.1% to 14.2% after surgery. With improved data capturing, missing data reduced from 29.22% to 1.05%. The time interval between surgeries was 10.58 months in 2002 and 14.49 months in 2012. Malays (40.2%) and those aged 61-70 years (38.1%) had the highest number of SECS. Those aged 40-50 years (10.96 months) and with poorer vision (9.97 months) had the shortest time interval between the 2 surgeries. The commonest surgical method was phacoemulsification (72.3%). Negeri Sembilan State had the highest SECS rate (35.91%) and Melaka had the shortest interval between surgeries (10.15 months). Despite an increase in the number of SECS, the time interval is still long. Poor presenting second eye vision and disparity among different states warrants the health authority's attention and intervention. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

  11. Evaluation of the IrisPlex DNA-based eye color prediction assay in a United States population.

    PubMed

    Dembinski, Gina M; Picard, Christine J

    2014-03-01

    DNA phenotyping is a rapidly developing area of research in forensic biology. Externally visible characteristics (EVCs) can be determined based on genotype data, specifically based on single nucleotide polymorphisms (SNPs). These SNPs are chosen based on their association with genes related to the phenotypic expression of interest, with known examples in eye, hair, and skin color traits. DNA phenotyping has forensic importance when unknown biological samples at a crime scene do not result in a criminal database hit; a phenotypic profile of the sample can therefore be used to develop investigational leads. IrisPlex, an eye color prediction assay, has previously shown high prediction rates for blue and brown eye color in a Dutch European population. The objective of this work was to evaluate its utility in a North American population. We evaluated six SNPs included in the IrisPlex assay in population sample collected from a USA college campus. We used a quantitative method of eye color classification based on (RGB) color components of digital photographs of the eye taken from each study volunteer so that each eye was placed in one of three eye color categories: brown, intermediate, or blue. Objective color classification was shown to correlate with basic human visual determination making it a feasible option for use in future prediction assay development. Using these samples and various models, the maximum prediction accuracies of the IrisPlex system after allele frequency adjustment was 58% and 95% brown and blue eye color predictions, respectively, and 11% for intermediate eye colors. Future developments should include incorporation of additional informative SNPs, specifically related to the intermediate eye color, and we recommend the use of a Bayesian approach as a prediction model as likelihood ratios can be determined for reporting purposes.

  12. Analysis of optokinetic response in zebrafish by computer-based eye tracking.

    PubMed

    Huber-Reggi, Sabina P; Mueller, Kaspar P; Neuhauss, Stephan C F

    2013-01-01

    Large-field movements in the visual surround trigger spontaneous, compensatory eye movements known as optokinetic response (OKR) in all vertebrates. In zebrafish (Danio rerio) the OKR is well developed at 5 days post fertilization and can be used in the laboratory for screening of visual performance following genetic manipulations or pharmaceutical treatments. Several setups for measurement of the zebrafish OKR have been described. All of them are based on the presentation of moving gratings to the larva or to the adult fish. However, they differ in the way of presenting gratings and in the method of analysis. Here, we describe a detailed protocol for our newest software that enables computer-generation of the moving stripes and automatic tracking of eye movement. This protocol makes it possible to quantitatively measure OKR in both larvae and adult fishes in a fast and reliable way.

  13. Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

    SciTech Connect

    Dai, Qi; Hao, Luoxi; Lin, Yi; Cui, Zhe

    2016-02-07

    Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330–390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions.

  14. Can't Look Away: An Eye-Tracking Based Attentional Disengagement Training for Depression.

    PubMed

    Ferrari, Gina R A; Möbius, Martin; van Opdorp, Amras; Becker, Eni S; Rinck, Mike

    To address shortcomings of purely reaction-time based attentional bias modification (ABM) paradigms, we developed an ABM task that is controlled by eye-tracking. This task allows to assess and train both disengagement from negative pictures and maintained attention to positive pictures. As a proof-of-principle study with an unselected student sample, this positive training (PT; N = 44) was compared to a negative training (NT; N = 42), which reinforced the opposite attentional pattern. Importantly, training trials were completed only if participants performed the correct gaze patterns. Results showed that higher depression levels were associated with slower disengagement from negative stimuli at baseline. As expected, the PT induced longer fixations on positive pictures and faster disengagement from negative pictures. The NT showed no changes in attentional processes. The groups did not differ in mood reactivity and recovery from a stressor. Advantages of using eye-tracking in ABM and potential applications of the training are discussed.

  15. Spectral optimization simulation of white light based on the photopic eye-sensitivity curve

    NASA Astrophysics Data System (ADS)

    Dai, Qi; Hao, Luoxi; Lin, Yi; Cui, Zhe

    2016-02-01

    Spectral optimization simulation of white light is studied to boost maximum attainable luminous efficacy of radiation at high color-rendering index (CRI) and various color temperatures. The photopic eye-sensitivity curve V(λ) is utilized as the dominant portion of white light spectra. Emission spectra of a blue InGaN light-emitting diode (LED) and a red AlInGaP LED are added to the spectrum of V(λ) to match white color coordinates. It is demonstrated that at the condition of color temperature from 2500 K to 6500 K and CRI above 90, such white sources can achieve spectral efficacy of 330-390 lm/W, which is higher than the previously reported theoretical maximum values. We show that this eye-sensitivity-based approach also has advantages on component energy conversion efficiency compared with previously reported optimization solutions.

  16. Three-dimensional OCT based guinea pig eye model: relating morphology and optics

    PubMed Central

    Pérez-merino, Pablo; Velasco-Ocana, Miriam; Martinez-Enriquez, Eduardo; Revuelta, Luis; McFadden, Sally A; Marcos, Susana

    2017-01-01

    Custom Spectral Optical Coherence Tomography (SOCT) provided with automatic quantification and distortion correction algorithms was used to measure the 3-D morphology in guinea pig eyes (n = 8, 30 days; n = 5, 40 days). Animals were measured awake in vivo under cyclopegia. Measurements showed low intraocular variability (<4% in corneal and anterior lens radii and <8% in the posterior lens radii, <1% interocular distances). The repeatability of the surface elevation was less than 2 µm. Surface astigmatism was the individual dominant term in all surfaces. Higher-order RMS surface elevation was largest in the posterior lens. Individual surface elevation Zernike terms correlated significantly across corneal and anterior lens surfaces. Higher-order-aberrations (except spherical aberration) were comparable with those predicted by OCT-based eye models. PMID:28736663

  17. Three-dimensional OCT based guinea pig eye model: relating morphology and optics.

    PubMed

    Pérez-Merino, Pablo; Velasco-Ocana, Miriam; Martinez-Enriquez, Eduardo; Revuelta, Luis; McFadden, Sally A; Marcos, Susana

    2017-04-01

    Custom Spectral Optical Coherence Tomography (SOCT) provided with automatic quantification and distortion correction algorithms was used to measure the 3-D morphology in guinea pig eyes (n = 8, 30 days; n = 5, 40 days). Animals were measured awake in vivo under cyclopegia. Measurements showed low intraocular variability (<4% in corneal and anterior lens radii and <8% in the posterior lens radii, <1% interocular distances). The repeatability of the surface elevation was less than 2 µm. Surface astigmatism was the individual dominant term in all surfaces. Higher-order RMS surface elevation was largest in the posterior lens. Individual surface elevation Zernike terms correlated significantly across corneal and anterior lens surfaces. Higher-order-aberrations (except spherical aberration) were comparable with those predicted by OCT-based eye models.

  18. A paper-based cantilever array sensor: Monitoring volatile organic compounds with naked eye.

    PubMed

    Fraiwan, Arwa; Lee, Hankeun; Choi, Seokheun

    2016-09-01

    Volatile organic compound (VOC) detection is critical for controlling industrial and commercial emissions, environmental monitoring, and public health. Simple, portable, rapid and low-cost VOC sensing platforms offer the benefits of on-site and real-time monitoring anytime and anywhere. The best and most practically useful approaches to monitoring would include equipment-free and power-free detection by the naked eye. In this work, we created a novel, paper-based cantilever sensor array that allows simple and rapid naked-eye VOC detection without the need for power, electronics or readout interface/equipment. This simple VOC detection method was achieved using (i) low-cost paper materials as a substrate and (ii) swellable thin polymers adhered to the paper. Upon exposure to VOCs, the polymer swelling adhered to the paper-based cantilever, inducing mechanical deflection that generated a distinctive composite pattern of the deflection angles for a specific VOC. The angle is directly measured by the naked eye on a 3-D protractor printed on a paper facing the cantilevers. The generated angle patterns are subjected to statistical algorithms (linear discriminant analysis (LDA)) to classify each VOC sample and selectively detect a VOC. We classified four VOC samples with 100% accuracy using LDA.

  19. Conducting community-based, culturally specific, eye disease screening clinics for urban African Americans with diabetes.

    PubMed

    Anderson, Robert M; Wolf, Fredric M; Musch, David C; Fitzgerald, James T; Johnson, Mark W; Nwankwo, Robin B; Robins, Lynne S; Oh, Mary S; Gillard, Mary Lou

    2002-01-01

    The purpose of this study was to evaluate the need for, and efficacy of, community-based culturally specific eye disease screening clinics for urban African Americans with diabetes. The study employed a variety of culturally specific methods in the design and performance of 43 community-based eye disease screening clinics in southeastern Michigan. One thousand, thirty-seven subjects were recruited for the study. Of that number, 817 identified themselves as African Americans and are the focus of this report. Of the 817 African-American patients screened, 84 (10%) needed to be examined by an ophthalmologist immediately (< 30 days), and 180 (22%) needed to be examined soon (within 1 to 3 months), while 544 (67%) were advised to return for another exam a year later. The project demonstrated that it was possible to use culturally specific techniques to identify a significant number of urban African Americans with diabetes in need of eye screening and treatment. However, lack of health insurance proved to be the primary barrier to receiving needed treatment. Although the project was successful, it is not a solution to what is essentially a health systems problem, ie, inadequate access to appropriate diabetes care for a significant number of our population.

  20. Safety and efficacy of a hydroxypropyl guar/polyethylene glycol/propylene glycol-based lubricant eye-drop in patients with dry eye.

    PubMed

    Labetoulle, Marc; Messmer, Elisabeth M; Pisella, Pierre-Jean; Ogundele, Abayomi; Baudouin, Christophe

    2017-04-01

    To demonstrate non-inferiority of a hydroxypropyl guar/polyethylene glycol/propylene glycol lubricating eye-drop (HPG/PEG/PG) compared with an osmoprotective carboxymethylcellulose/glycerine eye-drop (O/CMC) for ocular surface staining. This was a multicentre, randomised, observer-masked, parallel-group study. Adults with dry eye instilled HPG/PEG/PG/ or O/CMC 4 times daily for 35 days and then as needed through day 90. Total ocular surface staining (TOSS) score changes from baseline and Impact of Dry Eye on Everyday Life (IDEEL) treatment satisfaction module scores were assessed. Non-inferiority, based on TOSS score change from baseline, was concluded if the upper limit of the 2-sided CI was <2 units. Mean±SD patient age was 64.4±13.7 years; 94 patients were randomised to treatment (HPG/PEG/PG, n=46; O/CMC, n=48). Mean±SE TOSS score change from baseline to day 35 was -2.2±0.33 with HPG/PEG/PG and -1.7±0.47 with O/CMC (treatment difference, -0.47±0.47; p=0.38), and the non-inferiority criterion was met. IDEEL treatment satisfaction scores were similar between groups at day 35 and day 90. The most frequently reported adverse event was eye irritation (HPG/PEG/PG, n=2; O/CMC, n=3). HPG/PEG/PG and O/CMC reduced ocular surface damage, and HPG/PEG/PG was non-inferior to O/CMC. Both treatments were effective, convenient and well tolerated. NCT01863368, Results. 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/.

  1. 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.

  2. Assessing Visual Attention Using Eye Tracking Sensors in Intelligent Cognitive Therapies Based on Serious Games

    PubMed Central

    Frutos-Pascual, Maite; Garcia-Zapirain, Begonya

    2015-01-01

    This study examines the use of eye tracking sensors as a means to identify children's behavior in attention-enhancement therapies. For this purpose, a set of data collected from 32 children with different attention skills is analyzed during their interaction with a set of puzzle games. The authors of this study hypothesize that participants with better performance may have quantifiably different eye-movement patterns from users with poorer results. The use of eye trackers outside the research community may help to extend their potential with available intelligent therapies, bringing state-of-the-art technologies to users. The use of gaze data constitutes a new information source in intelligent therapies that may help to build new approaches that are fully-customized to final users' needs. This may be achieved by implementing machine learning algorithms for classification. The initial study of the dataset has proven a 0.88 (±0.11) classification accuracy with a random forest classifier, using cross-validation and hierarchical tree-based feature selection. Further approaches need to be examined in order to establish more detailed attention behaviors and patterns among children with and without attention problems. PMID:25985158

  3. A Crosslinked HA-Based Hydrogel Ameliorates Dry Eye Symptoms in Dogs

    PubMed Central

    Williams, David L.; Mann, Brenda K.

    2013-01-01

    Keratoconjunctivitis sicca, commonly referred to as dry eye or KCS, can affect both humans and dogs. The standard of care in treating KCS typically includes daily administration of eye drops to either stimulate tear production or to hydrate and lubricate the corneal surface. Lubricating eye drops are often applied four to six times daily for the life of the patient. In order to reduce this dosing regimen yet still provides sufficient hydration and lubrication, we have developed a crosslinked hydrogel based on a modified, thiolated hyaluronic acid (HA), xCMHA-S. This xCMHA-S gel was found to have different viscosity and rheologic behavior than solutions of noncrosslinked HA. The gel was also able to increase tear breakup time in rabbits, indicating a stabilization of the tear film. Further, in a preliminary clinical study of dogs with KCS, the gel significantly reduced the symptoms associated with KCS within two weeks while only being applied twice daily. The reduction of symptoms combined with the low dosing regimen indicates that this gel may lead to both improved patient health and owner compliance in applying the treatment. PMID:23840213

  4. Assessing visual attention using eye tracking sensors in intelligent cognitive therapies based on serious games.

    PubMed

    Frutos-Pascual, Maite; Garcia-Zapirain, Begonya

    2015-05-12

    This study examines the use of eye tracking sensors as a means to identify children's behavior in attention-enhancement therapies. For this purpose, a set of data collected from 32 children with different attention skills is analyzed during their interaction with a set of puzzle games. The authors of this study hypothesize that participants with better performance may have quantifiably different eye-movement patterns from users with poorer results. The use of eye trackers outside the research community may help to extend their potential with available intelligent therapies, bringing state-of-the-art technologies to users. The use of gaze data constitutes a new information source in intelligent therapies that may help to build new approaches that are fully-customized to final users' needs. This may be achieved by implementing machine learning algorithms for classification. The initial study of the dataset has proven a 0.88 (±0.11) classification accuracy with a random forest classifier, using cross-validation and hierarchical tree-based feature selection. Further approaches need to be examined in order to establish more detailed attention behaviors and patterns among children with and without attention problems.

  5. An eye movement based reading intervention in lexical and segmental readers with acquired dyslexia.

    PubMed

    Ablinger, Irene; von Heyden, Kerstin; Vorstius, Christian; Halm, Katja; Huber, Walter; Radach, Ralph

    2014-01-01

    Due to their brain damage, aphasic patients with acquired dyslexia often rely to a greater extent on lexical or segmental reading procedures. Thus, therapy intervention is mostly targeted on the more impaired reading strategy. In the present work we introduce a novel therapy approach based on real-time measurement of patients' eye movements as they attempt to read words. More specifically, an eye movement contingent technique of stepwise letter de-masking was used to support sequential reading, whereas fixation-dependent initial masking of non-central letters stimulated a lexical (parallel) reading strategy. Four lexical and four segmental readers with acquired central dyslexia received our intensive reading intervention. All participants showed remarkable improvements as evident in reduced total reading time, a reduced number of fixations per word and improved reading accuracy. Both types of intervention led to item-specific training effects in all subjects. A generalisation to untrained items was only found in segmental readers after the lexical training. Eye movement analyses were also used to compare word processing before and after therapy, indicating that all patients, with one exclusion, maintained their preferred reading strategy. However, in several cases the balance between sequential and lexical processing became less extreme, indicating a more effective individual interplay of both word processing routes.

  6. Customized schematic eye model for refraction correction design based on ocular wavefront and corneal topography measurements

    NASA Astrophysics Data System (ADS)

    Curatu, Eugene O.; Pettit, George H.; Campin, John A.

    2002-06-01

    The subject of this paper relates to the ocular optical design and vision analysis of refractive correction of the eye. After the purpose statement and the assumption list, the concept of the schematic eye matching a particular (measured) wavefront is introduced. This concept is based on the fact that the ocular wavefront, together with the corneal topography, can be seen as the mathematical global representation of the eye working in monochromatic light and having a foveal vision. The discussed design technique, including an iterative optimization method, could be applied in any ocular correction that utilizes cornea topography and/or ocular wavefront, e.g. contact lens or intra-corneal implant. However, the application this paper refers to is the ocular refractive correction by a procedure using the LADARVISION. It consists of surgical removal and subsequent replacement of a corneal flap on a stromal surface whose shape has been changed by laser ablation of the tissue. Subsequent sections of this paper are dedicated to establishing the limits of possible refractive correction, the influences of the flap and corneal topography into the refractive correction calculation. Finally a realistic evaluation of the results and a list of possible developments of this new optical design method are discussed.

  7. Eye-tracking of visual attention in web-based assessment using the Force Concept Inventory

    NASA Astrophysics Data System (ADS)

    Han, Jing; Chen, Li; Fu, Zhao; Fritchman, Joseph; Bao, Lei

    2017-07-01

    This study used eye-tracking technology to investigate students’ visual attention while taking the Force Concept Inventory (FCI) in a web-based interface. Eighty nine university students were randomly selected into a pre-test group and a post-test group. Students took the 30-question FCI on a computer equipped with an eye-tracker. There were seven weeks of instruction between the pre- and post-test data collection. Students’ performance on the FCI improved significantly from pre-test to post-test. Meanwhile, the eye-tracking results reveal that the time students spent on taking the FCI test was not affected by student performance and did not change from pre-test to post-test. Analysis of students’ attention to answer choices shows that on the pre-test students primarily focused on the naïve choices and ignored the expert choices. On the post-test, although students had shifted their primary attention to the expert choices, they still kept a high level of attention to the naïve choices, indicating significant conceptual mixing and competition during problem solving. Outcomes of this study provide new insights on students’ conceptual development in learning physics.

  8. Eye pain

    MedlinePlus

    Ophthalmalgia; Pain - eye ... Pain in the eye can be an important symptom of a health problem. Make sure you tell your health care provider if you have eye pain that does not go away. Tired eyes or ...

  9. Neuroanatomical Circuitry Associated with Exploratory Eye Movement in Schizophrenia: A Voxel-Based Morphometric Study

    PubMed Central

    Pan, Chao; Zhu, Risheng; Liu, Qi; Yan, Jun; Zhao, Qiang; Yuan, Huishu; Han, Yonghua; Yue, Weihua; Yan, Hao; Zhang, Dai

    2011-01-01

    Schizophrenic patients present abnormalities in a variety of eye movement tasks. Exploratory eye movement (EEM) dysfunction appears to be particularly specific to schizophrenia. However, the underlying mechanisms of EEM dysfunction in schizophrenia are not clearly understood. To assess the potential neuroanatomical substrates of EEM, we recorded EEM performance and conducted a voxel-based morphometric analysis of gray matter in 33 schizophrenic patients and 29 well matched healthy controls. In schizophrenic patients, decreased responsive search score (RSS) and widespread gray matter density (GMD) reductions were observed. Moreover, the RSS was positively correlated with GMD in distributed brain regions in schizophrenic patients. Furthermore, in schizophrenic patients, some brain regions with neuroanatomical deficits overlapped with some ones associated with RSS. These brain regions constituted an occipito-tempro-frontal circuitry involved in visual information processing and eye movement control, including the left calcarine cortex [Brodmann area (BA) 17], the left cuneus (BA 18), the left superior occipital cortex (BA 18/19), the left superior frontal gyrus (BA 6), the left cerebellum, the right lingual cortex (BA 17/18), the right middle occipital cortex (BA19), the right inferior temporal cortex (BA 37), the right dorsolateral prefrontal cortex (BA 46) and bilateral precentral gyri (BA 6) extending to the frontal eye fields (FEF, BA 8). To our knowledge, we firstly reported empirical evidence that gray matter loss in the occipito-tempro-frontal neuroanatomical circuitry of visual processing system was associated with EEM performance in schizophrenia, which may be helpful for the future effort to reveal the underlying neural mechanisms for EEM disturbances in schizophrenia. PMID:21991357

  10. A practical efficient human computer interface based on saccadic eye movements for people with disabilities.

    PubMed

    Soltani, Sima; Mahnam, Amin

    2016-03-01

    Human computer interfaces (HCI) provide new channels of communication for people with severe motor disabilities to state their needs, and control their environment. Some HCI systems are based on eye movements detected from the electrooculogram. In this study, a wearable HCI, which implements a novel adaptive algorithm for detection of saccadic eye movements in eight directions, was developed, considering the limitations that people with disabilities have. The adaptive algorithm eliminated the need for calibration of the system for different users and in different environments. A two-stage typing environment and a simple game for training people with disabilities to work with the system were also developed. Performance of the system was evaluated in experiments with the typing environment performed by six participants without disabilities. The average accuracy of the system in detecting eye movements and blinking was 82.9% at first tries with an average typing rate of 4.5cpm. However an experienced user could achieve 96% accuracy and 7.2cpm typing rate. Moreover, the functionality of the system for people with movement disabilities was evaluated by performing experiments with the game environment. Six people with tetraplegia and significant levels of speech impairment played with the computer game several times. The average success rate in performing the necessary eye movements was 61.5%, which increased significantly with practice up to 83% for one participant. The developed system is 2.6×4.5cm in size and weighs only 15g, assuring high level of comfort for the users.

  11. Rationale and methodology for a population-based study of eye diseases in Malay people: The Singapore Malay eye study (SiMES).

    PubMed

    Foong, Athena W P; Saw, Seang-Mei; Loo, Jing-Liang; Shen, Sunny; Loon, Seng-Chee; Rosman, Mohamad; Aung, Tin; Tan, Donald T H; Tai, E Shyong; Wong, Tien Y

    2007-01-01

    Although there are approximately 200 million people of Malay ethnicity living in Asia, the burden and risk factors of blinding eye diseases in this ethnic group are unknown. This study summarizes the rationale and study design of a population-based study of eye diseases among adult Malays in Singapore. A population-based cross-sectional study of Malays was designed in Singapore. The sampling frame consisted of all Malays aged 40-79 living in designated study areas in southwestern Singapore. From a list of 16,069 names provided by the Ministry of Home Affairs, age-stratified random sampling was used to select 5,600 names (1,400 people from each decade of 40-49, 50-59, 60-69, and 70-79 years). The target sample size for this study was 3,150 persons. Selected individuals were invited to a centralized clinic by letters, telephone calls, and home visits. Participants underwent standardized interview and assessment of blood pressure, anthropometry, presenting and best-corrected visual acuity, subjective refraction, ocular biometry, Goldmann tonometry, slit-lamp biomicroscopy, optic disc imaging, digital lens, and retinal photography. Blood and urine samples were collected for biochemical analyses and further stored for future studies. Selected participants also had gonioscopic examination, visual fields test, and assessment of ankle and brachial blood pressure to detect presence of peripheral vascular disease. This study provides population-based data on the prevalence of and risk factors for age-related eye diseases in people of Malay ethnicity in Singapore. Data from this study allow further understanding of the etiology and impact of eye diseases in this ethnic group.

  12. Neural-Net-Based Predictive Modeling of Spout Eye Size in Steelmaking

    NASA Astrophysics Data System (ADS)

    Palaneeswaran, Ekambaram; Brooks, Geoffrey; Xu, Xiaodong Bernard

    2012-06-01

    Gas stirring is commonly used in pyrometallurgical vessels to enhance mass and heat transfer and to promote impurity removal. In the case of secondary steelmaking, the spout eye area is caused by the escape of the gas from the top of the smelt where the liquid steel is directly exposed to the air, and oxygen can be picked up through the spout eye area that can reduce the quality of steel. Thus, controlling the size of the spout eye area is very important to improving the quality of the steel and to keeping the consistency of the product. The set of prevailing models to predict spout eye size are based on specific practically difficult variables, e.g., height of slag in hot upper layer of vessels and gas flow rate at nozzle exit. Recently, the cold model results showed that the stirring process can be conveniently monitored by the signals such as (1) the image signal from the top of the vessel, (2) the sound of the stirring process, and (3) the vibration on the wall of the vessel. This article outlines the key details of a novel research investigation using neural-network-based predictive modeling such as general regression neural networks (GRNN) with genetic adaptive calibrations. Predictive capacities and generalization potentials of five model constructs ( i.e., with different sets of input parameters) were explored, and the neural net modeling yielded encouraging outcomes, e.g., (1) excellent goodness-of-fit generalization measures including high values of correlation and R 2 validation parameters ( e.g., r = 0.921 and R 2 = 0.845 in a model validation), and (2) low values of root mean square of errors ( e.g., 3.034). Overall, the research outlined in this article demonstrates that the spout eye size can be effectively predicted by predictive neural net modeling with convenient and practically measurable variables such as sound and vibration observations on the steelmaking vessels. These results have only been demonstrated for a cold model of the process, and

  13. Development of a cyclodextrin-based aqueous cyclosporin A eye drop formulations.

    PubMed

    Jóhannsdóttir, Sunna; Jansook, Phatsawee; Stefánsson, Einar; Loftsson, Thorsteinn

    2015-09-30

    Cyclosporin A (CyA) is a lipophilic, cyclic polypeptide drug with anti-inflammatory properties. It is used in topical treatment of dry eyes and is now commercially available in oil based surfactant containing eye drops. Surfactants can irritate the eye surface causing burning, itching and irritation of the conjunctiva, and oil-based drops can result in blurred vision. Thus, the aim of this study was to develop surfactant free aqueous 0.05% (w/v) CyA eye drops where the drug is present in an aqueous vehicle containing CyA/cyclodextrin (CyA/CD) nanoparticles. The effects of the natural α-, β- and γ-cyclodextrins (αCD, βCD and γCD), as well as of the water soluble hydroxypropyl derivatives of γCD and αCD (HPγCD, HPαCD) and randomly methylated βCD (RMβCD), were determined in pure water. αCD had the best solubilizing effect increasing the solubility of CyA above 0.05% upon addition of only 5% (w/v) αCD. γCD did not have as good solubilizing effect but was tested further due to its superior ability to form nanoparticles and its favorable toxicological profile. Seven eye drop formulations were prepared and tested. All contained 0.05% (w/v) CyA in addition to polyvinyl alcohol, benzalkonium chloride, disodium edetate and various amounts of CD (αCD, γCD and mixtures thereof). When the formulation contained only αCD most of the drug was dissolved but some small aggregates were formed with hydrodynamic diameter of about 6 and 155 nm. When the formulation contained only γCD negligible CyA/CD complexation occurred with most of the drug present as solid CyA particles. When the formulation contained a mixture of αCD and γCD, where αCD concentration was at least 3% (w/v), the entire drug content was dissolved in the media under formation of relatively large (100-2000 nm) CyA/CD nanoparticles. αCD solubilized the drug while γCD enhanced nanoparticle formation. The effect of polyvinyl alcohol, benzalkonium chloride and disodium edetate on the nanoparticle

  14. GPU-based minimum variance beamformer for synthetic aperture imaging of the eye.

    PubMed

    Yiu, Billy Y S; Yu, Alfred C H

    2015-03-01

    Minimum variance (MV) beamforming has emerged as an adaptive apodization approach to bolster the quality of images generated from synthetic aperture ultrasound imaging methods that are based on unfocused transmission principles. In this article, we describe a new high-speed, pixel-based MV beamforming framework for synthetic aperture imaging to form entire frames of adaptively apodized images at real-time throughputs and document its performance in swine eye imaging case examples. Our framework is based on parallel computing principles, and its real-time operational feasibility was realized on a six-GPU (graphics processing unit) platform with 3,072 computing cores. This framework was used to form images with synthetic aperture imaging data acquired from swine eyes (based on virtual point-source emissions). Results indicate that MV-apodized image formation with video-range processing throughput (>20 fps) can be realized for practical aperture sizes (128 channels) and frames with λ/2 pixel spacing. Also, in a corneal wound detection experiment, MV-apodized images generated using our framework revealed apparent contrast enhancement of the wound site (10.8 dB with respect to synthetic aperture images formed with fixed apodization). These findings indicate that GPU-based MV beamforming can, in real time, potentially enhance image quality when performing synthetic aperture imaging that uses unfocused firings. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  15. Collaborative EDNAP exercise on the IrisPlex system for DNA-based prediction of human eye colour.

    PubMed

    Chaitanya, Lakshmi; Walsh, Susan; Andersen, Jeppe Dyrberg; Ansell, Ricky; Ballantyne, Kaye; Ballard, David; Banemann, Regine; Bauer, Christiane Maria; Bento, Ana Margarida; Brisighelli, Francesca; Capal, Tomas; Clarisse, Lindy; Gross, Theresa E; Haas, Cordula; Hoff-Olsen, Per; Hollard, Clémence; Keyser, Christine; Kiesler, Kevin M; Kohler, Priscila; Kupiec, Tomasz; Linacre, Adrian; Minawi, Anglika; Morling, Niels; Nilsson, Helena; Norén, Lina; Ottens, Renée; Palo, Jukka U; Parson, Walther; Pascali, Vincenzo L; Phillips, Chris; Porto, Maria João; Sajantila, Antti; Schneider, Peter M; Sijen, Titia; Söchtig, Jens; Syndercombe-Court, Denise; Tillmar, Andreas; Turanska, Martina; Vallone, Peter M; Zatkalíková, Lívia; Zidkova, Anastassiya; Branicki, Wojciech; Kayser, Manfred

    2014-07-01

    The IrisPlex system is a DNA-based test system for the prediction of human eye colour from biological samples and consists of a single forensically validated multiplex genotyping assay together with a statistical prediction model that is based on genotypes and phenotypes from thousands of individuals. IrisPlex predicts blue and brown human eye colour with, on average, >94% precision accuracy using six of the currently most eye colour informative single nucleotide polymorphisms (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, SLC45A2 (MATP) rs16891982, TYR rs1393350, and IRF4 rs12203592) according to a previous study, while the accuracy in predicting non-blue and non-brown eye colours is considerably lower. In an effort to vigorously assess the IrisPlex system at the international level, testing was performed by 21 laboratories in the context of a collaborative exercise divided into three tasks and organised by the European DNA Profiling (EDNAP) Group of the International Society of Forensic Genetics (ISFG). Task 1 involved the assessment of 10 blood and saliva samples provided on FTA cards by the organising laboratory together with eye colour phenotypes; 99.4% of the genotypes were correctly reported and 99% of the eye colour phenotypes were correctly predicted. Task 2 involved the assessment of 5 DNA samples extracted by the host laboratory from simulated casework samples, artificially degraded, and provided to the participants in varying DNA concentrations. For this task, 98.7% of the genotypes were correctly determined and 96.2% of eye colour phenotypes were correctly inferred. For Tasks 1 and 2 together, 99.2% (1875) of the 1890 genotypes were correctly generated and of the 15 (0.8%) incorrect genotype calls, only 2 (0.1%) resulted in incorrect eye colour phenotypes. The voluntary Task 3 involved participants choosing their own test subjects for IrisPlex genotyping and eye colour phenotype inference, while eye photographs were provided to the organising

  16. Eye- and feature-based modulation of onset rivalry caused by the preceding stimulus.

    PubMed

    Abe, Satoru; Kimura, Eiji; Goryo, Ken

    2011-11-09

    Pre-exposure to a stimulus can modulate initial perceptual dominance experienced in binocular rivalry with brief test stimuli (onset rivalry). This study investigated this modulating effect using both color and pattern stimuli. We confirmed separate contributions of eye- and feature-based suppressions and showed that their relative strength varied with temporal parameters. Eye-based suppression was stronger with a short test duration (10 ms) and shorter ISIs between the preceding and test stimuli. On the other hand, feature-based suppression grew with ISI and was more pronounced with a longer test duration (200 ms). We also investigated the nature of the modulating effect associated with feature-based suppression using chromatic gratings of high luminance contrast. Results revealed that different features of the preceding stimulus (i.e., color and orientation) exerted nearly independent effects on onset rivalry. However, different features shared their fate in competitive interactions for perceptual dominance; when one feature became dominant, the other also dominated. These findings suggest that competitive interactions for perceptual dominance and the modulation of these interactions are mediated at least partially by different mechanisms. Overall, the present findings are consistent with a theoretical view that initial dominance is established through competitive interactions at multiple levels of processing.

  17. Naked-eye quantitative aptamer-based assay on paper device.

    PubMed

    Zhang, Yun; Gao, Dong; Fan, Jinlong; Nie, Jinfang; Le, Shangwang; Zhu, Wenyuan; Yang, Jiani; Li, Jianping

    2016-04-15

    This work initially describes the design of low-cost, naked-eye quantitative aptamer-based assays by using microfluidic paper-based analytical device (μPAD). Two new detection motifs are proposed for quantitative μPAD measurement without using external electronic readers, which depend on the length of colored region in a strip-like μPAD and the number of colorless detection microzones in a multi-zone μPAD. The length measuring method is based on selective color change of paper from colorless to blue-black via formation of iodine-starch complex. The counting method is conducted on the basis of oxidation-reduction reaction between hydrogen peroxide and potassium permanganate. Their utility is well demonstrated with sensitive, specific detection of adenosine as a model analyte with the naked eye in buffer samples and undiluted human serum. These equipment-free quantitative methods proposed thus hold great potential for the development of more aptamer-based assays that are simple, cost-efficient, portable, and user-friendly for various point-of-care applications particularly in resource-constrained environments.

  18. Exploring the quiet eye in archery using field- and laboratory-based tasks.

    PubMed

    Gonzalez, Claudia C; Causer, Joe; Grey, Michael J; Humphreys, Glyn W; Miall, R Chris; Williams, A Mark

    2017-06-28

    The 'quiet eye' (QE)-a period of extended gaze fixation on a target-has been reported in many tasks that require accurate aiming. Longer quiet eye durations (QEDs) are reported in experts compared to non-experts and on successful versus less successful trials. The QE has been extensively studied in the field; however, the cognitive mechanisms underlying the QE are not yet fully understood. We investigated the QEDs of ten expert and ten novice archers in the field and in the laboratory using a computer-based archery task. The computer task consisted of shooting archery targets using a joystick. Random 'noise' (visual motion perturbation) was introduced at high and low levels to allow for the controlled examination of the effects of task complexity and processing demands. In this computer task, we also tested an additional group of ten non-archers as controls. In both field and computer tasks, eye movements were measured using electro-oculography. The expert archers exhibited longer QED compared to the novice archers in the field task. In the computer task, the archers again exhibited longer QEDs and were more accurate compared to non-archers. Furthermore, expert archers showed earlier QE onsets and longer QEDs during high noise conditions compared to the novices and non-archers. Our findings show skill-based effects on QED in field conditions and in a novel computer-based archery task, in which online (visual) perturbations modulated experts' QEDs. These longer QEDs in experts may be used for more efficient programming in which accurate predictions are facilitated by attention control.

  19. A Community-based Eye Care Intervention in Southern Egypt: Impact on Trachomatous Trichiasis Surgical Coverage.

    PubMed

    Mousa, Ahmed; Courtright, Paul; Kazanjian, Arminee; Bassett, Ken

    2015-01-01

    The purpose of this study was to measure the impact of a community-based intervention on uptake of trichiasis surgery in Southern Egypt. Four villages where trachoma is endemic were randomly selected in the Samalout district, Egypt. Two villages were selected for intervention (intervention villages) and two matched villages for nonintervention (nonintervention villages). The intervention model provided community information sessions, door-to-door health education, screening, and improvements in the clinical capacity of eye care providers. The intervention was evaluated through two pre- and post-intervention community-based surveys that included the prevalence of trachoma and the utilization of eye care services at local hospitals. All patients with trichiasis answered a questionnaire regarding surgical utilization and barriers. In the baseline survey, the trachomatous trichiasis (TT) surgical coverage was 22.7% (38.9% males, 16.7% females) in all villages. Following the intervention, the TT surgical coverage increased to 68% in villages that received the intervention (81.5% males, 60% females). Nonintervention villages had a TT surgical coverage of 26.1% (37.5% males, 20% females). In the intervention villages, the prevalence of TT significantly decreased from 9.4% (5.7% males, 11.8% females) to 3.8% (1.9% males, 5.1% females) (P = 0.013), in 2008. In nonintervention villages, there was a slight, but insignificant decrease in TT from 10.1% (3.1% males, 14.4% females) to 8.2% (3% males, 11.5% females) (P = 0.580). The major barriers to uptake of TT surgical services were: "Feeling no problem" (17.3%), "fear of surgery" (12.7%) and "cost" (12.7%). A community-based eye health education program with door-to-door screening significantly increased the uptake of TT surgical services. Although improvements to the delivery of surgical service are essential, they did not lead to any significant improvements in the nonintervention villages.

  20. Dew inspired breathing-based detection of genetic point mutation visualized by naked eye

    NASA Astrophysics Data System (ADS)

    Xie, Liping; Wang, Tongzhou; Huang, Tianqi; Hou, Wei; Huang, Guoliang; Du, Yanan

    2014-09-01

    A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions.

  1. Dew inspired breathing-based detection of genetic point mutation visualized by naked eye

    PubMed Central

    Xie, Liping; Wang, Tongzhou; Huang, Tianqi; Hou, Wei; Huang, Guoliang; Du, Yanan

    2014-01-01

    A novel label-free method based on breathing-induced vapor condensation was developed for detection of genetic point mutation. The dew-inspired detection was realized by integration of target-induced DNA ligation with rolling circle amplification (RCA). The vapor condensation induced by breathing transduced the RCA-amplified variances in DNA contents into visible contrast. The image could be recorded by a cell phone for further or even remote analysis. This green assay offers a naked-eye-reading method potentially applied for point-of-care liver cancer diagnosis in resource-limited regions. PMID:25199907

  2. Eye readable metal hydride based hydrogen tape sensor for health applications

    NASA Astrophysics Data System (ADS)

    Ngene, Peter; Radeva, Tsveta; Westerwaal, Ruud; Schreuders, Herman; Dam, Bernard

    2014-09-01

    Using the change in the intrinsic optical properties of YMg-based thin films upon exposure to hydrogen, we observe the presence of hydrogen at concentrations as low as 20 ppm just by a change in color. The eye-visible color change circumvents the use of any electronics in this device, thereby making it an inexpensive H2 detector. The detector shows high selectivity towards H2 in H2-O2 - mixtures, and responds within 20 s to 0.25% H2 in the presence of 18% O2.

  3. Machine vision based on the concept of contrast sensitivity of the human eye

    NASA Astrophysics Data System (ADS)

    Bezzubik, Vitali; Belashenkov, Nikolai; Vdovin, Gleb

    2014-09-01

    The model of contrast sensitivity function (CSF) of machine vision system, based on the CSF of the human visual system is proposed. By analogy with the human eye, we employ the concept of ganglion cell receptive field to the artificial light-sensitive elements. By further following this concept, we introduced quantative metrics of local and global contrast of digital image. We suggested that the contrast sensitivity threshold forms an iso-line in the parameter space contrast - spatial frequency. The model, implemented in a computer vision system, has been compared to the results of contrast sensitivity research, conducted directly with the human visual system, and demonstrated a good match.

  4. Video-based data acquisition system for use in eye blink classical conditioning procedures in sheep.

    PubMed

    Nation, Kelsey; Birge, Adam; Lunde, Emily; Cudd, Timothy; Goodlett, Charles; Washburn, Shannon

    2016-11-04

    Pavlovian eye blink conditioning (EBC) has been extensively studied in humans and laboratory animals, providing one of the best-understood models of learning in neuroscience. EBC has been especially useful in translational studies of cerebellar and hippocampal function. We recently reported a novel extension of EBC procedures for use in sheep, and now describe new advances in a digital video-based system. The system delivers paired presentations of conditioned stimuli (CSs; a tone) and unconditioned stimuli (USs; an air puff to the eye), or CS-alone "unpaired" trials. This system tracks the linear distance between the eyelids to identify blinks occurring as either unconditioned (URs) or conditioned (CRs) responses, to a resolution of 5 ms. A separate software application (Eye Blink Reviewer) is used to review and autoscore the trial CRs and URs, on the basis of a set of predetermined rules, permitting an operator to confirm (or rescore, if needed) the autoscore results, thereby providing quality control for accuracy of scoring. Learning curves may then be quantified in terms of the frequencies of CRs over sessions, both on trials with paired CS-US presentations and on CS-alone trials. The latency to CR onset, latency to CR peak, and occurrence of URs are also obtained. As we demonstrated in two example cases, this video-based system provides efficient automated means to conduct EBC in sheep and can facilitate fully powered studies with multigroup designs that involve paired and unpaired training. This can help extend new studies in sheep, a species well suited for translational studies of neurodevelopmental disorders resulting from gestational exposure to drugs, toxins, or intrauterine distress.

  5. Dynamic Eye Tracking Based Metrics for Infant Gaze Patterns in the Face-Distractor Competition Paradigm

    PubMed Central

    Ahtola, Eero; Stjerna, Susanna; Yrttiaho, Santeri; Nelson, Charles A.; Leppänen, Jukka M.; Vanhatalo, Sampsa

    2014-01-01

    Objective To develop new standardized eye tracking based measures and metrics for infants’ gaze dynamics in the face-distractor competition paradigm. Method Eye tracking data were collected from two samples of healthy 7-month-old (total n = 45), as well as one sample of 5-month-old infants (n = 22) in a paradigm with a picture of a face or a non-face pattern as a central stimulus, and a geometric shape as a lateral stimulus. The data were analyzed by using conventional measures of infants’ initial disengagement from the central to the lateral stimulus (i.e., saccadic reaction time and probability) and, additionally, novel measures reflecting infants gaze dynamics after the initial disengagement (i.e., cumulative allocation of attention to the central vs. peripheral stimulus). Results The results showed that the initial saccade away from the centrally presented stimulus is followed by a rapid re-engagement of attention with the central stimulus, leading to cumulative preference for the central stimulus over the lateral stimulus over time. This pattern tended to be stronger for salient facial expressions as compared to non-face patterns, was replicable across two independent samples of 7-month-old infants, and differentiated between 7 and 5 month-old infants. Conclusion The results suggest that eye tracking based assessments of infants’ cumulative preference for faces over time can be readily parameterized and standardized, and may provide valuable techniques for future studies examining normative developmental changes in preference for social signals. Significance Standardized measures of early developing face preferences may have potential to become surrogate biomarkers of neurocognitive and social development. PMID:24845102

  6. A Fuzzy-Based Fusion Method of Multimodal Sensor-Based Measurements for the Quantitative Evaluation of Eye Fatigue on 3D Displays.

    PubMed

    Bang, Jae Won; Choi, Jong-Suk; Heo, Hwan; Park, Kang Ryoung

    2015-05-07

    With the rapid increase of 3-dimensional (3D) content, considerable research related to the 3D human factor has been undertaken for quantitatively evaluating visual discomfort, including eye fatigue and dizziness, caused by viewing 3D content. Various modalities such as electroencephalograms (EEGs), biomedical signals, and eye responses have been investigated. However, the majority of the previous research has analyzed each modality separately to measure user eye fatigue. This cannot guarantee the credibility of the resulting eye fatigue evaluations. Therefore, we propose a new method for quantitatively evaluating eye fatigue related to 3D content by combining multimodal measurements. This research is novel for the following four reasons: first, for the evaluation of eye fatigue with high credibility on 3D displays, a fuzzy-based fusion method (FBFM) is proposed based on the multimodalities of EEG signals, eye blinking rate (BR), facial temperature (FT), and subjective evaluation (SE); second, to measure a more accurate variation of eye fatigue (before and after watching a 3D display), we obtain the quality scores of EEG signals, eye BR, FT and SE; third, for combining the values of the four modalities we obtain the optimal weights of the EEG signals BR, FT and SE using a fuzzy system based on quality scores; fourth, the quantitative level of the variation of eye fatigue is finally obtained using the weighted sum of the values measured by the four modalities. Experimental results confirm that the effectiveness of the proposed FBFM is greater than other conventional multimodal measurements. Moreover, the credibility of the variations of the eye fatigue using the FBFM before and after watching the 3D display is proven using a t-test and descriptive statistical analysis using effect size.

  7. A Fuzzy-Based Fusion Method of Multimodal Sensor-Based Measurements for the Quantitative Evaluation of Eye Fatigue on 3D Displays

    PubMed Central

    Bang, Jae Won; Choi, Jong-Suk; Heo, Hwan; Park, Kang Ryoung

    2015-01-01

    With the rapid increase of 3-dimensional (3D) content, considerable research related to the 3D human factor has been undertaken for quantitatively evaluating visual discomfort, including eye fatigue and dizziness, caused by viewing 3D content. Various modalities such as electroencephalograms (EEGs), biomedical signals, and eye responses have been investigated. However, the majority of the previous research has analyzed each modality separately to measure user eye fatigue. This cannot guarantee the credibility of the resulting eye fatigue evaluations. Therefore, we propose a new method for quantitatively evaluating eye fatigue related to 3D content by combining multimodal measurements. This research is novel for the following four reasons: first, for the evaluation of eye fatigue with high credibility on 3D displays, a fuzzy-based fusion method (FBFM) is proposed based on the multimodalities of EEG signals, eye blinking rate (BR), facial temperature (FT), and subjective evaluation (SE); second, to measure a more accurate variation of eye fatigue (before and after watching a 3D display), we obtain the quality scores of EEG signals, eye BR, FT and SE; third, for combining the values of the four modalities we obtain the optimal weights of the EEG signals BR, FT and SE using a fuzzy system based on quality scores; fourth, the quantitative level of the variation of eye fatigue is finally obtained using the weighted sum of the values measured by the four modalities. Experimental results confirm that the effectiveness of the proposed FBFM is greater than other conventional multimodal measurements. Moreover, the credibility of the variations of the eye fatigue using the FBFM before and after watching the 3D display is proven using a t-test and descriptive statistical analysis using effect size. PMID:25961382

  8. SU-E-I-37: Eye Lens Dose Reduction From CT Scan Using Organ Based Tube Current Modulation

    SciTech Connect

    Liu, H; Liu, T; Xu, X; Wu, J; Zhuo, W

    2015-06-15

    Purpose: To investigate the eye lens dose reduction by CT scan with organ based tube current modulation (OBTCM) using GPU Monte Carlo code ARCHER-CT. Methods: 36 X-ray sources and bowtie filters were placed around the patient head with the projection angle interval of 10° for one rotation of CT scan, each projection was simulated respectively. The voxel eye models with high resolution(0.1mm*0.1mm*0.1mm) were used in the simulation and different tube voltage including 80kVp, 100kVp, 120kVp and 140kVp were taken into consideration. Results: The radiation doses to the eye lens increased with the tube voltage raised from 80kVp to 140kVp, and the dose results from 0° (AP) direction are much higher than those from 180° (PA) direction for all the 4 different tube voltage investigated. This 360° projection dose characteristic enables organ based TCM, which can reduce the eye lens dose by more than 55%. Conclusion: As the eye lens belongs to superficial tissues, its radiation dose to external exposure like CT is direction sensitive, and this characteristic feature makes organ based TCM to be an effective way to reduce the eye lens dose, so more clinical use of this technique were recommended. National Nature Science Foundation of China(No.11475047)

  9. Infrared Eye: Prototype 2

    DTIC Science & Technology

    2016-06-07

    The Infrared (IR) Eye was developed with support from the National Search and Rescue Secretariat (NSS), in view of improving the efficiency of...airborne search-and rescue operations. The IR Eye concept is based on the human eye and uses simultaneously two fields of view to optimize area coverage and...within the wide field and slaved to the operator’s line of sight by means of an eye -tracking system. The images from both cameras are fused and shown

  10. Symmetric Kullback-Leibler Metric Based Tracking Behaviors for Bioinspired Robotic Eyes.

    PubMed

    Liu, Hengli; Luo, Jun; Wu, Peng; Xie, Shaorong; Li, Hengyu

    2015-01-01

    A symmetric Kullback-Leibler metric based tracking system, capable of tracking moving targets, is presented for a bionic spherical parallel mechanism to minimize a tracking error function to simulate smooth pursuit of human eyes. More specifically, we propose a real-time moving target tracking algorithm which utilizes spatial histograms taking into account symmetric Kullback-Leibler metric. In the proposed algorithm, the key spatial histograms are extracted and taken into particle filtering framework. Once the target is identified, an image-based control scheme is implemented to drive bionic spherical parallel mechanism such that the identified target is to be tracked at the center of the captured images. Meanwhile, the robot motion information is fed forward to develop an adaptive smooth tracking controller inspired by the Vestibuloocular Reflex mechanism. The proposed tracking system is designed to make the robot track dynamic objects when the robot travels through transmittable terrains, especially bumpy environment. To perform bumpy-resist capability under the condition of violent attitude variation when the robot works in the bumpy environment mentioned, experimental results demonstrate the effectiveness and robustness of our bioinspired tracking system using bionic spherical parallel mechanism inspired by head-eye coordination.

  11. Classification of iRBD and Parkinson's disease patients based on eye movements during sleep.

    PubMed

    Christensen, Julie A E; Koch, Henriette; Frandsen, Rune; Kempfner, Jacob; Arvastson, Lars; Christensen, Soren R; Sorensen, Helge B D; Jennum, Poul

    2013-01-01

    Patients suffering from the sleep disorder idiopathic rapid-eye-movement sleep behavior disorder (iRBD) have been observed to be in high risk of developing Parkinson's disease (PD). This makes it essential to analyze them in the search for PD biomarkers. This study aims at classifying patients suffering from iRBD or PD based on features reflecting eye movements (EMs) during sleep. A Latent Dirichlet Allocation (LDA) topic model was developed based on features extracted from two electrooculographic (EOG) signals measured as parts in full night polysomnographic (PSG) recordings from ten control subjects. The trained model was tested on ten other control subjects, ten iRBD patients and ten PD patients, obtaining a EM topic mixture diagram for each subject in the test dataset. Three features were extracted from the topic mixture diagrams, reflecting "certainty", "fragmentation" and "stability" in the timely distribution of the EM topics. Using a Naive Bayes (NB) classifier and the features "certainty" and "stability" yielded the best classification result and the subjects were classified with a sensitivity of 95 %, a specificity of 80% and an accuracy of 90 %. This study demonstrates in a data-driven approach, that iRBD and PD patients may exhibit abnorm form and/or timely distribution of EMs during sleep.

  12. Biological diversity, dietary diversity, and eye health in developing country populations: establishing the evidence-base.

    PubMed

    Bélanger, Julie; Johns, Timothy

    2008-09-01

    Human and ecosystem health converge around biological diversity issues. Cultivated and wild plants as food and medicine make essential contributions to human health, which in turn provides rationales for conservation. While wild and cultivated plant diversity reasonably facilitates dietary diversity and positive health outcomes, the challenges of demonstrating this relationship limit its impact in concept, policy, and practice. We present a rationale for testing the dietary contribution of biological diversity to improved eye health as a case study based on existing phytochemical, pharmacological, and clinical knowledge. We consider the empirical evidence needed to substantiate, interpret, and apply this relationship at a population and ecosystem level within a unified research framework. Epidemiological data strongly support the prevention of childhood vitamin A deficiency blindness, cataract, and age-related macular degeneration by fruit and vegetable consumption. Phytonutrients, including the carotenoids lutein and zeaxanthin, protect the eye from oxidative stress and harmful light exposure. Laboratory, community, and population level research should prioritize food composition of dietary plants from both agriculture and the wild. Intervention studies, focus groups, and transmission of knowledge of local species and varieties within communities will further interpretation of epidemiological data. Population-based studies combining clinical data and measures of access and consumption of biological diversity are key to demonstrating the important relationships among biodiversity, dietary diversity, and health outcomes.

  13. Graphene-Based Bioinspired Compound Eyes for Programmable Focusing and Remote Actuation.

    PubMed

    Wang, Lanlan; Li, Fang; Liu, Hongzhong; Jiang, Weitao; Niu, Dong; Li, Rui; Yin, Lei; Shi, Yongsheng; Chen, Bangdao

    2015-09-30

    Inspired by creatures' eyes, bioinspired compound eyes (BCEs) endowed with larger fields of view and vari-focal capability are extremely appealing in micro-optical devices. However, the present actuation strategies of BCEs commonly demand complicated fields, e.g., electro-wetting actuation, dielectrophoretic drive and pressure gradient, which greatly limits their practical applications. In this work, the photothermal conversion of graphene nanosheets (GNSs) is first utilized to fabricate lenslets toward BCEs. Under the actuation of near-infrared (nIR) pulsed laser, GNSs absorb photo energy and convert it to thermal energy, which increases the temperature of lenslets and then leads to the adjustment of lenslet curvature. At a result, BCEs manifest a reversible 4-fold zoom and a wide FOV up to 160°. In addition, BCEs also perform the programmable focusing by selectively confining nIR laser to a vari-focal region. In contrast with traditional BCEs, graphene-based BCEs are versatile with wide FOV and vari-focal ability by nIR actuation. Herein, these excellent properties make graphene-based BCEs promising for remote-driven microfluidic devices.

  14. Symmetric Kullback-Leibler Metric Based Tracking Behaviors for Bioinspired Robotic Eyes

    PubMed Central

    Liu, Hengli; Luo, Jun; Wu, Peng; Xie, Shaorong; Li, Hengyu

    2015-01-01

    A symmetric Kullback-Leibler metric based tracking system, capable of tracking moving targets, is presented for a bionic spherical parallel mechanism to minimize a tracking error function to simulate smooth pursuit of human eyes. More specifically, we propose a real-time moving target tracking algorithm which utilizes spatial histograms taking into account symmetric Kullback-Leibler metric. In the proposed algorithm, the key spatial histograms are extracted and taken into particle filtering framework. Once the target is identified, an image-based control scheme is implemented to drive bionic spherical parallel mechanism such that the identified target is to be tracked at the center of the captured images. Meanwhile, the robot motion information is fed forward to develop an adaptive smooth tracking controller inspired by the Vestibuloocular Reflex mechanism. The proposed tracking system is designed to make the robot track dynamic objects when the robot travels through transmittable terrains, especially bumpy environment. To perform bumpy-resist capability under the condition of violent attitude variation when the robot works in the bumpy environment mentioned, experimental results demonstrate the effectiveness and robustness of our bioinspired tracking system using bionic spherical parallel mechanism inspired by head-eye coordination. PMID:27019592

  15. Clinical evaluation of an oil-based lubricant eyedrop in dry eye patients with lipid deficiency.

    PubMed

    Baudouin, Christophe; Galarreta, David J; Mrukwa-Kominek, Ewa; Böhringer, Daniel; Maurino, Vincenzo; Guillon, Michel; Rossi, Gemma C M; Van der Meulen, Ivanka J; Ogundele, Abayomi; Labetoulle, Marc

    2017-03-10

    To evaluate and compare the efficacy of a lipid-based lubricant eyedrop formulation (hydroxypropyl guar/propylene glycol/phospholipid [HPG/PG/PL]) with preservative-free saline for the treatment of dry eye. This was a prospective, multicenter, randomized, single-masked, parallel-group phase 4 clinical study. Patients ≥18 years diagnosed with dry eye received 1 drop of saline 4 times daily (QID) for 15 days during a run-in phase, followed by randomization. Patients then instilled HPG/PG/PL or saline QID through day 35 and as needed through day 90. Change in tear film break-up time (TFBUT), change in total ocular surface staining (TOSS) score, and Impact of Dry Eye on Everyday Life (IDEEL) were evaluated on day 35. Increase in TFBUT from baseline to day 35 was assessed during the interim and final analyses. Mean ± SE difference between the HPG/PG/PL (n = 110) and saline groups (n = 100) was 1.3 ± 0.4 seconds (interim analysis; 95% confidence interval [CI] 0.5-2.1 seconds; p = 0.0012) and 1.0 ± 0.3 seconds (final analysis; 95% CI 0.4-1.6 seconds; p = 0.0011), demonstrating the superiority of HPG/PG/PL. The mean ± SE difference between the HPG/PG/PL and saline groups for IDEEL treatment effectiveness scores was 16.0 ± 3.6 (95% CI 8.9-23.1; p<0.0001). No significant differences in TOSS scores or IDEEL inconvenience scores were observed between treatment groups. Thirty-five days of QID HPG/PG/PL treatment resulted in a statistically significant improvement in TFBUT and IDEEL treatment effectiveness scores compared with saline but not in TOSS or IDEEL treatment inconvenience scores. HPG/PG/PL was well-tolerated by patients.

  16. Web-based Training in German University Eye Hospitals – Education 2.0?

    PubMed Central

    Handzel, Daniel M.; Hesse, L.

    2011-01-01

    Purpose: To analyse web-based training in ophthalmology offered by German university eye hospitals. Methods: In January 2010 the websites of all 36 German university hospitals were searched for information provided for visitors, students and doctors alike. We evaluated the offer in terms of quantity and quality. Results: All websites could be accessed at the time of the study. 28 pages provided information for students and doctors, one page only for students, three exclusively for doctors. Four pages didn’t offer any information for these target groups. The websites offered information on events like congresses or students curricular education, there were also material for download for these events or for other purposes. We found complex e-learning-platforms on 9 pages. These dealt with special ophthalmological topics in a didactic arrangement. In spite of the extensive possibilities offered by the technology of Web 2.0, many conceivable tools were only rarely made available. It was not always possible to determine if the information provided was up-to-date, very often the last actualization of the content was long ago. On one page the date for the last change was stated as 2004. Conclusion: Currently there are 9 functional e-learning-applications offered by German university eye hospitals. Two additional hospitals present links to a project of the German Ophthalmological Society. There was a considerable variation in quantity and quality. No website made use of crediting successful studying, e.g. with CME-points or OSCE-credits. All German university eye hospitals present themselves in the World Wide Web. However, the lack of modern, technical as well as didactical state-of-the-art learning applications is alarming as it leaves an essential medium of today’s communication unused. PMID:21866245

  17. Strategy To Fabricate Naked-Eye Readout Ultrasensitive Plasmonic Nanosensor Based on Enzyme Mimetic Gold Nanoclusters.

    PubMed

    Zhao, Qian; Huang, Haowen; Zhang, Lingyang; Wang, Linqian; Zeng, Yunlong; Xia, Xiaodong; Liu, Fengping; Chen, Yi

    2016-01-19

    It is broadly interesting but remains a big challenge to explore nanomaterials-based methods to enable naked-eye observation and determination of ultratrace biomarkers and drugs. In this study, we developed a straightforward and extendable plasmonic nanosensor to enable visually quantitative determination of ultratrace target molecules through combining the use of enzyme-mimetic gold nanoclusters (AuNCs). Starting from sandwiched antibody-antigen (i.e., an analyte)-antibody structure, we conjugated AuNCs on the outer layer antibody to catalyze the decomposition of hydrogen peroxide used to reduce HAuCl4 into gold nanopartilces (AuNPs) for naked eye readout. This strategy is in theory applicable to all immunoreactions available and the protocol proposed to attach AuNCs onto an antibody is suitable to all proteins. The applicability of this type of nanosensor was validated by the determination of various ultratrace analytes such as protein avidin, breast cancer antigen, thyroid hormone, and even methamphetamine (MA), giving a naked-eye-readout limit of detection (LOD), down to 1.0 × 10(-20) M protein avidin, 7.52 × 10(-14) U/mL breast cancer antigen 15-3, 2.0 × 10(-15) mg/mL 3,5,3'-L-triiodothyronine and 2.3 × 10(-18) mg/mL MA. This strategy is thus considered an ultrasensitive way to fabricate plasmonic nanosensors, having wide and invaluable application potential in clinical, biological, and environmental studies, and in food quality control.

  18. Evaluation of helmet-mounted display targeting symbology based on eye tracking technology

    NASA Astrophysics Data System (ADS)

    Wang, Lijing; Wen, Fuzhen; Ma, Caixin; Zhao, Shengchu; Liu, Xiaodong

    2014-06-01

    The purpose of this paper is to find the Target Locator Lines (TLLs) which perform best by contrasting and comparing experiment based on three kinds of TTLs of fighter HMD. 10 university students, male, with an average age of 21-23, corrected visual acuity 1.5, participated in the experiment. In the experiment, head movement data was obtained by TrackIR. The geometric relationship between the coordinates of the real world and coordinates of the visual display was obtained by calculating the distance from viewpoint to midpoint of both eyes and the head movement data. Virtual helmet system simulation experiment environment was created by drawing TLLs of fighter HMD in the flight simulator visual scene. In the experiment, eye tracker was used to record the time and saccade trajectory. The results were evaluated by the duration of the time and saccade trajectory. The results showed that the symbol"locator line with digital vector length indication" cost most time and had the longest length of the saccade trajectory. It is the most ineffective and most unacceptable way. "Locator line with extending head vector length symbol" cost less time and had less length of the saccade trajectory. It is effective and acceptable;"Locator line with reflected vector length symbol" cost the least time and had the least length of the saccade trajectory. It is the most effective and most acceptable way. "Locator line with reflected vector length symbol" performs best. The results will provide reference value for the research of TTLs in future.

  19. HotEye (tm) Based Coordinate Measuring Machine for Forging Industry

    SciTech Connect

    OG Technologies

    2003-06-09

    The objective of this project is to develop a 3 dimensional measurement system for the domestic forging industry based on HotEye{trademark}. This technology will allow high definition camera to accurately image a red hot object. The project marries conventional Coordinate Measurement Machine ''CMM'' technology to HotEye{trademark} technology to permit the accurate measurement of forged parts while they are at high temperature. Being able to take such measurements will dramatically reduce the amount of scrap produced by the domestic forging industry. This industry wastes a significant amount of energy because of the high rate of scrap it produces. OGT will: (1) Develop a 3D measurement sensor head that will work on a part at a temperature up to 1,450 C with an accuracy of 0.1mm or better and with a scanning speed of less than 10 seconds for an area of 100mm x 100mm. (2) Develop a Virtual-Fixturing software package to alleviate the need of precise hard fixturing. (3) Integrate the 3D measurement sensor head and the Virtual-Fixturing software into a standard CMM, both hardware (replacing the probes) and software (data format and user interface match) so that the system can automatically perform a complete preprogrammed measurement of a hot product. (4) Test and evaluate the system in a forging facility.

  20. Optimized sign language video coding based on eye-tracking analysis

    NASA Astrophysics Data System (ADS)

    Agrafiotis, Dimitris; Canagarajah, C. N.; Bull, David R.; Dye, Matt; Twyford, Helen; Kyle, Jim; Chung How, James

    2003-06-01

    The imminent arrival of mobile video telephony will enable deaf people to communicate - as hearing people have been able to do for a some time now - anytime/anywhere in their own language sign language. At low bit rates coding of sign language sequences is very challenging due to the high level of motion and the need to maintain good image quality to aid with understanding. This paper presents optimised coding of sign language video at low bit rates in a way that will favour comprehension of the compressed material by deaf users. Our coding suggestions are based on an eye-tracking study that we have conducted which allows us to analyse the visual attention of sign language viewers. The results of this study are included in this paper. Analysis and results for two coding methods, one using MPEG-4 video objects and the second using foveation filtering are presented. Results with foveation filtering are very promising, offering a considerable decrease in bit rate in a way which is compatible with the visual attention patterns of deaf people, as these were recorded in the eye tracking study.

  1. Eye Diseases

    MedlinePlus

    ... the back of the eye Macular degeneration - a disease that destroys sharp, central vision Diabetic eye problems ... defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and ...

  2. Eye Injuries

    MedlinePlus

    The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or ...

  3. Eye Cancer

    MedlinePlus

    Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in ...

  4. Eye Allergies

    MedlinePlus

    ... Sep. 01, 2016 Eye allergies, also called allergic conjunctivitis, are quite common. They occur when the eyes ... can tear and burn. Unlike other kinds of conjunctivitis, eye allergies are not spread from person to ...

  5. Watery eyes

    MedlinePlus

    ... the most common causes of excess tearing is dry eyes . Drying causes the eyes to become uncomfortable, which stimulates the body to produce too many tears. One of the main tests for tearing is to check whether the eyes ...

  6. Occupational exposure to water based paint and symptoms from the skin and eyes.

    PubMed Central

    Wieslander, G; Norbäck, D; Edling, C

    1994-01-01

    Water based paints contain organic solvents and many additives, such as biocides, surfactants, pigments, binders, amines, and monomers. The chemical complexity may introduce new potential health hazards to house painters, in particular irritative and allergic disorders. This study was performed to compare how house painters experience work with water based paints or solvent based paints, and to evaluate whether exposure to water based paints increases mucous membrane and dermal symptoms among house painters. 255 male house painters aged 20 to 65 were invited to participate in the study. Controls were two industrial populations, in total 302 men, without exposure to water based paints. Self administered questionnaires were used to assess the painter's experiences of working with different types of paints and the occurrence of symptoms in the exposed and unexposed groups. Hygiene measurements were performed during normal working days when only water based paints and no solvent based paints were used. The painters were exposed to low concentrations of dust, metals, ammonia, formaldehyde, and volatile organic compounds. The work environment was considered better when working with water based paints than with solvent based paints. There were more complaints of frequent urination when working with water based paint. Taste or olfactory disturbances were less common. General as well as work related eye and skin irritation was more common among the exposed workers. For other symptoms no significant differences were found. The study indicates that the introduction of water based paints has improved the work environment for house painters. Water based paints cause less discomfort and airway irritation than the earlier solvent based paints. Adverse general health effects seem low. Some of the painters may have dermal symptoms caused by the components in water based paints. PMID:8130846

  7. Evaluation of Corneal Deformation Analyzed with Scheimpflug Based Device in Healthy Eyes and Diseased Ones

    PubMed Central

    Lanza, Michele; Cennamo, Michela; Iaccarino, Stefania; Irregolare, Carlo; Bifani, Mario; Gironi Carnevale, Ugo Antonello

    2014-01-01

    This study was designed to evaluate the correlation between corneal biomechanical and morphological data in healthy eyes, eyes that underwent myopic photorefractive keratectomy (PRK), keratoconus affected eyes, and keratoconus affected eyes that underwent corneal collagen crosslinking (CCC). Complete clinical eye examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been performed. Linear regression between central corneal thickness (CCT), intraocular pressure (IOP), and anterior corneal curvature measured with Sim'K (KM), versus corneal deformation parameters measured with Corvis ST in the different groups, has been run using SPSS software version 18.0. We evaluated 64 healthy eyes of 64 patients with a mean refractive error of −0.65 ± 1.68 D (measured as spherical equivalent), 17 eyes of 17 patients that underwent myopic PRK for a mean refractive defect of −4.91 ± 2.05 D (measured as spherical equivalent), 16 eyes of 16 patients affected by keratconus (stage 2-3 of Amsler Classification), and 13 eyes of 13 patients affected by keratoconus that underwent CCC. Our data suggest that corneal curvature would have a greater influence on corneal deformation than CCT; in fact KM values are more strongly associated with more CST parameters both about corneal change in shape and both about the corneal ability to come back at original shape. PMID:25054144

  8. CT based three-dimensional measurement of orbit and eye anthropometry.

    PubMed

    Weaver, Ashley A; Loftis, Kathryn L; Tan, Josh C; Duma, Stefan M; Stitzel, Joel D

    2010-10-01

    To measure eye and orbit anthropometric variation within the normal population by using CT images and to determine the effects of age and sex on eye and orbit anthropometry. Quantification of eye and orbit anthropometric variation within the normal population and between persons of different age and sex is important in the prediction and prevention of eye injury. A systematic method was developed to align head CT images three dimensionally and to measure ocular and orbital parameters in 39 subjects. Twenty-four measurements were collected along the orbital rim, to quantify the orbital aperture. Protrusions of the brow and the eye were measured, along with relative distances, to describe location of the eye within the orbit. The orbit widened with age, and significant relations were identified between orbital aperture and eye location measurements, both of which varied significantly between the sexes. The comprehensive set of measurements collected in this study provides three-dimensional information on orbit geometry, as well as placement of the eye within the orbit. These measurements and the methodology used will contribute to the development of finite element models of the orbit and eye for computational modeling purposes and may be useful in the design of eye protection equipment.

  9. Optical Zone Centration Accuracy Using Corneal Fixation-based SMILE Compared to Eye Tracker-based Femtosecond Laser-assisted LASIK for Myopia.

    PubMed

    Reinstein, Dan Z; Gobbe, Marine; Gobbe, Louis; Archer, Timothy J; Carp, Glenn I

    2015-09-01

    To compare the optical zone centration accuracy between myopic eyes treated with small incision lenticule extraction (SMILE) and LASIK. Retrospective analysis of 100 consecutive eyes treated with SMILE (the SMILE group) with the corneal fixation-based centration VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) and a matched group of 100 eyes treated with LASIK (the LASIK group) with VisuMax flap creation and eye tracker-based centration MEL 90 excimer laser (Carl Zeiss Meditec) ablation. In SMILE, the corneal vertex of the coaxially fixating eye was aligned with the vertex of the curved contact glass. In LASIK, the treatment was centered on the coaxially sighted corneal light reflex (first Purkinje image). A tangential (instantaneous) curvature preoperative to postoperative difference map was generated for each eye. A fixed grid and set of concentric circles were superimposed on the difference map to measure the offset between the optical zone center and corneal vertex (0,0), and vector analysis was used for comparative analysis at 3 months postoperatively. Mean centration offset was 0.20 ± 0.11 mm for the SMILE group and 0.17 ± 0.10 mm for the LASIK group, with no statistically significant difference between groups (P >.05). In the SMILE group, the optical zone was centered within 0.1 mm of the corneal vertex in 17% of eyes, within 0.2 mm in 55% of eyes, within 0.3 mm in 81% of eyes, and within 0.4 mm in 96% of eyes. In the LASIK group, the optical zone was centered within 0.1 mm of the corneal vertex in 24% of eyes, within 0.2 mm in 62% of eyes, within 0.3 mm in 92% of eyes, and within 0.4 mm in 98% of eyes. There was no systematic directional decentration in either group. Optical zone centration accuracy was no different between SMILE and LASIK with the MEL 90 laser. Copyright 2015, SLACK Incorporated.

  10. Gender is a major factor explaining discrepancies in eye colour prediction based on HERC2/OCA2 genotype and the IrisPlex model.

    PubMed

    Martinez-Cadenas, Conrado; Peña-Chilet, Maria; Ibarrola-Villava, Maider; Ribas, Gloria

    2013-07-01

    In recent years, several studies have greatly increased our understanding of the genetic basis underlying human eye colour variation. A large percentage of the eye colour diversity present in humans can already be genetically explained, so much so that different DNA-based eye colour prediction models, such as IrisPlex, have been recently developed for forensic purposes. Though these models are already highly accurate, they are by no means perfect, with many genotype-phenotype discrepancies still remaining unresolved. In this work we have genotyped six SNPs associated with eye colour (IrisPlex) in 535 individuals from Spain, a Mediterranean population. Aside from different SNP frequencies in Spain compared to Northern Europe, the results for eye colour prediction are quite similar to other studies. However, we have found an association between gender and eye colour prediction. When comparing similar eye colour genetic profiles, females tend, as a whole, to have darker eyes than males (and, conversely, males lighter than females). These results are also corroborated by the revision and meta-analysis of data from previously published eye colour genetic studies in several Caucasian populations, which significantly support the fact that males are more likely to have blue eyes than females, while females tend to show higher frequencies of green and brown eyes than males. This significant gender difference would suggest that there is an as yet unidentified gender-related factor contributing to human eye colour variation.

  11. A multi level system design for vigilance measurement based on head posture estimation and eyes blinking

    NASA Astrophysics Data System (ADS)

    Teyeb, Ines; Jemai, Olfa; Zaied, Mourad; ben Amar, Chokri

    2015-12-01

    Driving security is an important task for human society. The major challenge in the field of accident avoidance systems is the driver vigilance monitoring. The lack of vigilance can be noticed by various ways, such as, fatigue, drowsiness and distraction. Hence, the need of a reliable driver's vigilance decrease detection system which can alert drivers before a mishap happens. In this paper, we present a novel approach for vigilance estimation based on multilevel system by combining head movement analysis and eyes blinking. We have used Viola and Jones algorithm to analyse head movement and a classification system using wavelet networks for eyelid closure measuring. The contribution of our application is classifiying the vigilance state at multi level. This is different from the binary-class (awakening or hypovigilant state) existing in most popular systems.

  12. High-speed, image-based eye tracking with a scanning laser ophthalmoscope

    PubMed Central

    Sheehy, Christy K.; Yang, Qiang; Arathorn, David W.; Tiruveedhula, Pavan; de Boer, Johannes F.; Roorda, Austin

    2012-01-01

    We demonstrate a high-speed, image-based tracking scanning laser ophthalmoscope (TSLO) that can provide high fidelity structural images, real-time eye tracking and targeted stimulus delivery. The system was designed for diffraction-limited performance over an 8° field of view (FOV) and operates with a flexible field of view of 1°–5.5°. Stabilized videos of the retina were generated showing an amplitude of motion after stabilization of 0.2 arcmin or less across all frequencies. In addition, the imaging laser can be modulated to place a stimulus on a targeted retinal location. We show a stimulus placement accuracy with a standard deviation less than 1 arcmin. With a smaller field size of 2°, individual cone photoreceptors were clearly visible at eccentricities outside of the fovea. PMID:23082300

  13. Similarity-Based Interference During Language Comprehension: Evidence from Eye Tracking During Reading

    PubMed Central

    Gordon, Peter C.; Hendrick, Randall; Johnson, Marcus; Lee, Yoonhyoung

    2006-01-01

    The nature of working memory operation during complex sentence comprehension was studied using eye-tracking methodology. Readers had difficulty when the syntax of a sentence required them to hold two similar noun phrases (NPs) in working memory before syntactically and semantically integrating either of the NPs with a verb. In sentence structures that placed these NPs at the same linear distances from one another but allowed integration with a verb for one of the NPs, the comprehension difficulty was not seen. These results are interpreted as indicating that similarity-based interference occurs online during the comprehension of complex sentences and that the degree of memory accessibility conventionally associated with different types of NPs does not have a strong effect on sentence processing. PMID:17087585

  14. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

    SciTech Connect

    Xu, Jie; Wang, Xin E-mail: mubz@tongji.edu.cn; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong E-mail: mubz@tongji.edu.cn

    2016-07-15

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  15. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection.

    PubMed

    Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

    2016-07-01

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  16. A novel lobster-eye imaging system based on Schmidt-type objective for X-ray-backscattering inspection

    NASA Astrophysics Data System (ADS)

    Xu, Jie; Wang, Xin; Zhan, Qi; Huang, Shengling; Chen, Yifan; Mu, Baozhong

    2016-07-01

    This paper presents a novel lobster-eye imaging system for X-ray-backscattering inspection. The system was designed by modifying the Schmidt geometry into a treble-lens structure in order to reduce the resolution difference between the vertical and horizontal directions, as indicated by ray-tracing simulations. The lobster-eye X-ray imaging system is capable of operating over a wide range of photon energies up to 100 keV. In addition, the optics of the lobster-eye X-ray imaging system was tested to verify that they meet the requirements. X-ray-backscattering imaging experiments were performed in which T-shaped polymethyl-methacrylate objects were imaged by the lobster-eye X-ray imaging system based on both the double-lens and treble-lens Schmidt objectives. The results show similar resolution of the treble-lens Schmidt objective in both the vertical and horizontal directions. Moreover, imaging experiments were performed using a second treble-lens Schmidt objective with higher resolution. The results show that for a field of view of over 200 mm and with a 500 mm object distance, this lobster-eye X-ray imaging system based on a treble-lens Schmidt objective offers a spatial resolution of approximately 3 mm.

  17. 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.

  18. Magnetic eye tracking in mice.

    PubMed

    Payne, Hannah L; Raymond, Jennifer L

    2017-09-05

    Eye movements provide insights about a wide range of brain functions, from sensorimotor integration to cognition; hence, the measurement of eye movements is an important tool in neuroscience research. We describe a method, based on magnetic sensing, for measuring eye movements in head-fixed and freely moving mice. A small magnet was surgically implanted on the eye, and changes in the magnet angle as the eye rotated were detected by a magnetic field sensor. Systematic testing demonstrated high resolution measurements of eye position of <0.1°. Magnetic eye tracking offers several advantages over the well-established eye coil and video-oculography methods. Most notably, it provides the first method for reliable, high-resolution measurement of eye movements in freely moving mice, revealing increased eye movements and altered binocular coordination compared to head-fixed mice. Overall, magnetic eye tracking provides a lightweight, inexpensive, easily implemented, and high-resolution method suitable for a wide range of applications.

  19. Impact of Dry Eye Syndrome on Vision-Related Quality of Life in a Non-Clinic-Based General Population

    PubMed Central

    2012-01-01

    Background Dry eye syndrome (DES) is a common ocular disorder occurring in general population. The purpose of this study is to evaluate the impact of DES on vision-related quality of life (QoL) in a non-clinic-based general population. Methods This population-based cross-sectional study enrolled subjects older than 40 years, who took part in an epidemiological study on dry eye in Sanle Community, Shanghai. Apart from the collection of sociodemographics, dry eye symptoms, and other clinical data, a Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) was administered to all subjects. Comparisons of the NEI VFQ-25 subscale item scores and composite score were made among subgroups divided according to the presence of dry eye symptoms or signs. Multivariate regression analysis was performed to investigate the relationship between the clinical variables and the VFQ-25 composite score. Results A total of 229 participants were enrolled in the study, with an average age of (60.7 ±10.1) years old. Majority of these participants were female (59.8 %, 137/229). The total DES symptom scores (TDSS) in subjects either with definite DES or only with dry eye symptoms were significantly higher (F = 60.331, P < 0.001). The values of tear break-up time (TBUT) and Schirmer test were significantly lower in participants with DES and those with dry eye signs only (F = 55.158 and 40.778, P < 0.001). The composite score of the NEI VFQ-25 was significantly lower in subjects with DES (F = 4.901, P = 0.003). Moreover, the subscale scores of ocular pain and mental health were significantly lower in those with either DES or dry eye symptoms only (F = 10.962 and 7.362 respectively, both P < 0.001). The multiple regression analysis showed that the TDSS had a significant negative correlation with the VFQ-25 composite score as well as with the subscale score for ocular pain and mental health, even after the

  20. Impact of dry eye syndrome on vision-related quality of life in a non-clinic-based general population.

    PubMed

    Le, Qihua; Zhou, Xiaodong; Ge, Ling; Wu, Liangcheng; Hong, Jiaxu; Xu, Jianjiang

    2012-07-16

    Dry eye syndrome (DES) is a common ocular disorder occurring in general population. The purpose of this study is to evaluate the impact of DES on vision-related quality of life (QoL) in a non-clinic-based general population. This population-based cross-sectional study enrolled subjects older than 40 years, who took part in an epidemiological study on dry eye in Sanle Community, Shanghai. Apart from the collection of sociodemographics, dry eye symptoms, and other clinical data, a Chinese version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) was administered to all subjects. Comparisons of the NEI VFQ-25 subscale item scores and composite score were made among subgroups divided according to the presence of dry eye symptoms or signs. Multivariate regression analysis was performed to investigate the relationship between the clinical variables and the VFQ-25 composite score. A total of 229 participants were enrolled in the study, with an average age of (60.7±10.1) years old. Majority of these participants were female (59.8 %, 137/229). The total DES symptom scores (TDSS) in subjects either with definite DES or only with dry eye symptoms were significantly higher (F=60.331, P<0.001). The values of tear break-up time (TBUT) and Schirmer test were significantly lower in participants with DES and those with dry eye signs only (F=55.158 and 40.778, P<0.001). The composite score of the NEI VFQ-25 was significantly lower in subjects with DES (F=4.901, P=0.003). Moreover, the subscale scores of ocular pain and mental health were significantly lower in those with either DES or dry eye symptoms only (F=10.962 and 7.362 respectively, both P<0.001). The multiple regression analysis showed that the TDSS had a significant negative correlation with the VFQ-25 composite score as well as with the subscale score for ocular pain and mental health, even after the adjustment of all other factors (all P<0.01). The symptoms of dry eye are associated

  1. From a Bird's Eye View to a Worm's Eye View: A Comprehension-Based Program of Foreign Language Instruction.

    ERIC Educational Resources Information Center

    Manning, Phyllis J.

    The language teaching method presented here is an inter-related set of techniques for teaching target comprehension skills directly to students on both university and high school levels. Three elements of the method are discussed: (1) the basics of a comprehension-based classroom; (2) the expanded speaking component; and (3) the expanded reading…

  2. From a Bird's Eye View to a Worm's Eye View: A Comprehension-Based Program of Foreign Language Instruction.

    ERIC Educational Resources Information Center

    Manning, Phyllis J.

    The language teaching method presented here is an inter-related set of techniques for teaching target comprehension skills directly to students on both university and high school levels. Three elements of the method are discussed: (1) the basics of a comprehension-based classroom; (2) the expanded speaking component; and (3) the expanded reading…

  3. Prevalence and risk factors of dry eye disease among a hospital-based population in southeast China.

    PubMed

    Li, Jinyang; Zheng, Ke; Deng, Zifeng; Zheng, Jingwei; Ma, Huixiang; Sun, Li; Chen, Wei

    2015-01-01

    To investigate the prevalence of dry eye disease (DED) and distribution of associated risk factors among a hospital-based population. In this cross-sectional study, we collected detailed information of clinically defined moderate-to-severe patients with dry eye among a consecutive hospital-based population, including age trend, gender structure, frequency of symptoms, and distribution of associated environmental/occupational risk factors. Of 6,657 consecutive outpatients aged older than 20 years, symptomatic dry eye presented in 635 subjects (9.54%). Five hundred thirty-two of these 635 subjects (7.99%) were clinically diagnosed as defined DED that combined with positive signs. Women (10.41%) were significantly higher than men (5.21%) (P<0.001). Overexposure to visual display terminal was a major risk factor for DED among young men and women (56.2%). Our study also found occupational conditions with the risk of exposure to adverse environment made up over half of all 532 patients with dry eye. The use of contact lenses was closely associated with DED in young women, and history of ocular surgeries might be another factor associated with DED in old people. One hundred sixty-three of 371 female patients with dry eye (43.9%) were associated with hormonal changes. The incidence of meibomian gland dysfunction-related DED increased gradually with age. There were only 10 patients with dry eye (1.9%) associated with Sjögren syndrome, and all of them were women. Environmental and occupational factors were strongly associated with DED and constituted the major proportion in a hospital-based population. A classification of DED based on the distribution of risk factors was recommended for clinical use.

  4. A Clinic-based Survey of Clinical Characteristics and Practice Pattern of Dry Eye in Japan.

    PubMed

    Kawashima, Motoko; Yamada, Masakazu; Suwaki, Kazuhisa; Shigeyasu, Chika; Uchino, Miki; Hiratsuka, Yoshimune; Yokoi, Norihiko; Tsubota, Kazuo

    2017-03-01

    The aim of this study was to investigate the clinical characteristics and practice pattern of patients with dry eye disease (DED) in eye clinics across Japan. A multi-center, cross-sectional study was conducted among patients with DED who visited eye clinics in Japan. Subjective symptoms, patient's background, ocular surface features, and tear function were evaluated. Main outcome measures were tear break-up time (TBUT), Schirmer I value, kerato-conjunctival staining score, and dry eye symptom questionnaire score. Initially, 463 subjects were enrolled, and 449 cases (63 male and 386 female; mean age, 62.6 ± 15.7 years) were included in the final analysis. Overall, 94.9% of patients had a shortened TBUT (≤5 s), and 54.6% had an aqueous tear deficiency (Schirmer I value ≤5 mm). The most prevalent subtype of dry eye was aqueous-deficient dry eye, which was present in 35.0% of all patients, followed by short-BUT-type dry eye, which was seen in 26.7%. The two most common DED subtypes were aqueous-deficient and short-BUT-type dry eye. Shortened TBUT is the most common feature of dry eye, regardless of subtype. The current treatment choice mainly consisted of hyaluronic acid, two novel mucin secretagogues, diquafosol and rebamipide, and steroidal eye drops. University Hospital Medical Information Network: UMIN (registries no. UMIN 000015890). Japan Dry Eye Society, Tokyo, Japan, and Santen Pharmaceutical Co., Ltd., Osaka, Japan.

  5. Structure Modulates Similarity-Based Interference in Sluicing: An Eye Tracking study

    PubMed Central

    Harris, Jesse A.

    2015-01-01

    In cue-based content-addressable approaches to memory, a target and its competitors are retrieved in parallel from memory via a fast, associative cue-matching procedure under a severely limited focus of attention. Such a parallel matching procedure could in principle ignore the serial order or hierarchical structure characteristic of linguistic relations. I present an eye tracking while reading experiment that investigates whether the sentential position of a potential antecedent modulates the strength of similarity-based interference, a well-studied effect in which increased similarity in features between a target and its competitors results in slower and less accurate retrieval overall. The manipulation trades on an independently established Locality bias in sluiced structures to associate a wh-remnant (which ones) in clausal ellipsis with the most local correlate (some wines), as in The tourists enjoyed some wines, but I don't know which ones. The findings generally support cue-based parsing models of sentence processing that are subject to similarity-based interference in retrieval, and provide additional support to the growing body of evidence that retrieval is sensitive to both the structural position of a target antecedent and its competitors, and the specificity or diagnosticity of retrieval cues. PMID:26733893

  6. Eye gaze performance for children with severe physical impairments using gaze-based assistive technology-A longitudinal study.

    PubMed

    Borgestig, Maria; Sandqvist, Jan; Parsons, Richard; Falkmer, Torbjörn; Hemmingsson, Helena

    2016-01-01

    Gaze-based assistive technology (gaze-based AT) has the potential to provide children affected by severe physical impairments with opportunities for communication and activities. This study aimed to examine changes in eye gaze performance over time (time on task and accuracy) in children with severe physical impairments, without speaking ability, using gaze-based AT. A longitudinal study with a before and after design was conducted on 10 children (aged 1-15 years) with severe physical impairments, who were beginners to gaze-based AT at baseline. Thereafter, all children used the gaze-based AT in daily activities over the course of the study. Compass computer software was used to measure time on task and accuracy with eye selection of targets on screen, and tests were performed with the children at baseline, after 5 months, 9-11 months, and after 15-20 months. Findings showed that the children improved in time on task after 5 months and became more accurate in selecting targets after 15-20 months. This study indicates that these children with severe physical impairments, who were unable to speak, could improve in eye gaze performance. However, the children needed time to practice on a long-term basis to acquire skills needed to develop fast and accurate eye gaze performance.

  7. Eye gaze performance for children with severe physical impairments using gaze-based assistive technology—A longitudinal study

    PubMed Central

    Borgestig, Maria; Sandqvist, Jan; Parsons, Richard; Falkmer, Torbjörn; Hemmingsson, Helena

    2016-01-01

    ABSTRACT Gaze-based assistive technology (gaze-based AT) has the potential to provide children affected by severe physical impairments with opportunities for communication and activities. This study aimed to examine changes in eye gaze performance over time (time on task and accuracy) in children with severe physical impairments, without speaking ability, using gaze-based AT. A longitudinal study with a before and after design was conducted on 10 children (aged 1–15 years) with severe physical impairments, who were beginners to gaze-based AT at baseline. Thereafter, all children used the gaze-based AT in daily activities over the course of the study. Compass computer software was used to measure time on task and accuracy with eye selection of targets on screen, and tests were performed with the children at baseline, after 5 months, 9–11 months, and after 15–20 months. Findings showed that the children improved in time on task after 5 months and became more accurate in selecting targets after 15–20 months. This study indicates that these children with severe physical impairments, who were unable to speak, could improve in eye gaze performance. However, the children needed time to practice on a long-term basis to acquire skills needed to develop fast and accurate eye gaze performance. PMID:26496529

  8. Thermal fluctuation based study of aqueous deficient dry eyes by non-invasive thermal imaging.

    PubMed

    Azharuddin, Mohammad; Bera, Sumanta Kr; Datta, Himadri; Dasgupta, Anjan Kr

    2014-03-01

    In this paper we have studied the thermal fluctuation patterns occurring at the ocular surface of the left and right eyes for aqueous deficient dry eye (ADDE) patients and control subjects by thermal imaging. We conducted our experiment on 42 patients (84 eyes) with aqueous deficient dry eyes and compared with 36 healthy volunteers (72 eyes) without any history of ocular surface disorder. Schirmer's test, Tear Break-up Time, tear Meniscus height and fluorescein staining tests were conducted. Ocular surface temperature measurement was done, using an FL-IR thermal camera and thermal fluctuation in left and right eyes was calculated and analyzed using MATLAB. The time series containing the sum of squares of the temperature fluctuation on the ocular surface were compared for aqueous deficient dry eye and control subjects. Significant statistical difference between the fluctuation patterns for control and ADDE was observed (p < 0.001 at 95% confidence interval). Thermal fluctuations in left and right eyes are significantly correlated in controls but not in ADDE subjects. The possible origin of such correlation in control and lack of correlation in the ADDE subjects is discussed in the text.

  9. A Microcomputer-Based Software Package for Eye-Monitoring Research. Technical Report No. 434.

    ERIC Educational Resources Information Center

    McConkie, George W.; And Others

    A software package is described that collects and reduces eye behavior data (eye position and pupil size) using an IBM-PC compatible computer. Written in C language for speed and portability, it includes several features: (1) data can be simultaneously collected from other sources (such as electroencephalography and electromyography); (2)…

  10. An Examination of Cognitive Processing of Multimedia Information Based on Viewers' Eye Movements

    ERIC Educational Resources Information Center

    Liu, Han-Chin; Chuang, Hsueh-Hua

    2011-01-01

    This study utilized qualitative and quantitative designs and eye-tracking technology to understand how viewers process multimedia information. Eye movement data were collected from eight college students (non-science majors) while they were viewing web pages containing different types of text and illustrations depicting the mechanism of…

  11. Speed and accuracy of head- and eye-based aiming systems at high vertical acceleration.

    PubMed

    Ineson, Judith; Durnell, Laurence; Ebbage, J Louise; Jarrett, Don N; Neary, Catherine; Reed, Mark A

    2004-05-01

    The benefits of using a head tracker in a fast jet to aim weapons and control sensor direction have been amply demonstrated, but head direction is difficult to control at high G. An experiment was conducted to assess whether aiming using the eye, rather than the head, might be advantageous. A centrifuge provided sustained accelerations of up to 8 Gz. Participating aircrew were asked to point at static targets using head- or eye-aiming, maintain the acquisition while the target was lit, and then transfer to the next target as quickly as possible. A helmet-mounted scene camera recorded the subject's view of the target board. A laser mounted by the scene camera was used for head-aiming and to determine head direction. The eye tracker camera and illuminator were also helmet-mounted. The eye and scene images were recorded and analyzed off-line. Eye-aiming acquisition times and accuracy were affected only slightly by Gz; however, both head-aiming speed and accuracy deteriorated as Gz increased. Eye-aiming was substantially faster than head-aiming at all Gz levels, but head-aiming was more accurate under these experimental conditions. Subjective ratings supported the objective data. A majority of subjects preferred eye to head as an aiming mechanism. Eye-aiming was faster and easier to use than head-aiming at all Gz levels, and particularly at high Gz.

  12. An Examination of Cognitive Processing of Multimedia Information Based on Viewers' Eye Movements

    ERIC Educational Resources Information Center

    Liu, Han-Chin; Chuang, Hsueh-Hua

    2011-01-01

    This study utilized qualitative and quantitative designs and eye-tracking technology to understand how viewers process multimedia information. Eye movement data were collected from eight college students (non-science majors) while they were viewing web pages containing different types of text and illustrations depicting the mechanism of…

  13. Naked eye detection of trace cancer biomarkers based on biobarcode and enzyme-assisted DNA recycling hybrid amplifications.

    PubMed

    Zhou, Wenjiao; Su, Jiao; Chai, Yaqin; Yuan, Ruo; Xiang, Yun

    2014-03-15

    Naked eye-based detection has received increasing research interest due to the simplicity nature of this type of assay. However, improving the sensitivity of the naked eye detection method for the monitoring of trace amount of target molecules remains a major challenge. Herein, we describe a biobarcode and an enzyme-assisted DNA recycling hybrid amplification strategy for naked eye detection of sub-picomolar carcinoembryonic antigen (CEA), a cancer biomarker. The presence of CEA and the corresponding antibodies results in the formation of immunocomplexes and the capture of the biobarcodes in a microplate. The massive barcode DNAs released from the biobarcodes hybridize with the G-quadruplex inactive hairpin DNA probes and form catalytic nicking sites for N.BstNBI endonuclease, which cleaves the barcode DNA/hairpin partial dsDNA, releases the G-quadruplex active sequences and recycles the barcode DNA. Due to the barcode DNA recycling process, numerous G-quadruplex active sequences are generated and associate with hemin to form peroxidase mimicking enzymes, which convert colorless ABTS(2-) to green color intensified ABTS(•-) to achieve naked eye detection of CEA down to 0.025 ng mL(-1) (0.14 pM). The naked eye detection strategy reported herein can be applied also to complicated serum sample matrix, making this approach hold great promise for point-of-care diagnostic applications. © 2013 Published by Elsevier B.V.

  14. Fabrication of flexible silver nanowire conductive films and transmittance improvement based on moth-eye nanostructure array

    NASA Astrophysics Data System (ADS)

    Zhang, Chengpeng; Zhu, Yuwen; Yi, Peiyun; Peng, Linfa; Lai, Xinmin

    2017-07-01

    Transparent conductive electrodes (TCEs) are widely used in optoelectronic devices, such as touch screens, liquid-crystal displays and light-emitting diodes. To date, the material of the most commonly used TCEs was indium-tin oxide (ITO), which had several intrinsic drawbacks that limited its applications in the long term, including relatively high material cost and brittleness. Silver nanowire (AgNW), as one of the alternative materials for ITO TCEs, has already gained much attention all over the world. In this paper, we reported a facile method to greatly enhance the transmittance of the AgNW TCEs without reducing the electrical conductivity based on moth-eye nanostructures, and the moth-eye nanostructures were fabricated by using a roll-to-roll ultraviolet nanoimprint lithography process. Besides, the effects of mechanical pressure and bending on the moth-eye nanostructure layer were also investigated. In the research, the optical transmittance of the flexible AgNW TCEs was enhanced from 81.3% to 86.0% by attaching moth-eye nanostructures onto the other side of the flexible polyethylene terephthalate substrate while the electrical conductivity of the AgNW TCEs was not sacrificed. This research can provide a direction for the cost-effective fabrication of moth-eye nanostructures and the transmittance improvement of the flexible transparent electrodes.

  15. Improving eye care follow-up adherence in diabetic patients with ocular abnormalities: the effectiveness of patient contracts in a free, pharmacy-based eye screening.

    PubMed

    Aleo, C L; Murchison, A P; Dai, Y; Hark, L A; Mayro, E L; Collymore, B; Haller, J A

    2015-07-01

    Patient contracts are increasingly utilized in medical practice and have the potential to improve health outcomes in high-risk populations. However, as a relatively new tool, there has been limited research regarding the efficacy of patient contracts. Diabetic retinopathy (DR) is one of the leading causes of vision impairment in adults in the US and only 50-60% of adults with diabetes adhere to annual dilated fundus exam recommendations. This study aimed to evaluate the impact of patient contracts on follow-up adherence in diabetic patients with ocular abnormalities after a free, pharmacy-based eye screening. This prospective study implemented a non-invasive, non-mydriatic fundus camera in an urban, community-based pharmacy setting to screen for ocular diseases in patients with diabetes. Patients were assigned to the contract or non-contract group. Patients who signed a contract agreed to: 1) review their results with their primary care doctor, 2) follow-up with an ophthalmologist if their results were abnormal, and 3) inform research staff if/when they completed an eye care appointment. All study participants and their primary care doctors were notified of their results via mail. Follow-up questionnaires were administered to all patients by telephone three months after the screening results. 500 patients were screened and 113 (22.6%) had abnormal results. Of the patients who had abnormal results, 83 (74.3%) were able to be contacted. Of the 83 patients who were able to be contacted, the majority of patients were African American (73.5%) and female (56.6%). The mean age was 54.7 years. Of those, 34 (41.0%) adhered to follow-up recommendations. There was no significant difference in follow-up adherence between the contract (38.1%) and non-contract group (43.9%) (P = 0.59). In addition, 70.4% of patients did not comply with at least one measure of the contract agreement. Contracts did not increase follow-up adherence to eye appointments in diabetic patients with

  16. Posterior segment eye disease in sub-Saharan Africa: review of recent population-based studies

    PubMed Central

    Bastawrous, Andrew; Burgess, Philip I; Mahdi, Abdull M; Kyari, Fatima; Burton, Matthew J; Kuper, Hannah

    2014-01-01

    Objective To assess the burden of posterior segment eye diseases (PSEDs) in sub-Saharan Africa (SSA). Methods We reviewed published population-based data from SSA and other relevant populations on the leading PSED, specifically glaucoma, diabetic retinopathy and age-related macular degeneration, as causes of blindness and visual impairment in adults. Data were extracted from population-based studies conducted in SSA and elsewhere where relevant. Results PSEDs, when grouped or as individual diseases, are a major contributor to blindness and visual impairment in SSA. PSED, grouped together, was usually the second leading cause of blindness after cataract, ranging as a proportion of blindness from 13 to 37%. Conclusions PSEDs are likely to grow in importance as causes of visual impairment and blindness in SSA in the coming years as populations grow, age and become more urban in lifestyle. African-based cohort studies are required to help estimate present and future needs and plan services to prevent avoidable blindness. PMID:24479434

  17. Wide field OCT based microangiography in living human eye (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhang, Qinqin; Chen, Chieh-Li; Chu, Zhongdi; Zhang, Anqi; An, Lin; Durbin, Mary; Sharma, Utkarsh; Rosenfeld, Philip J.; Wang, Ruikang K.

    2016-03-01

    To investigate the application of optical microangiography (OMAG) in living human eye. Patients with different macular diseases were recruited, including diabetic retinopathy (DR), geographic atrophy (GA), retinitis pigmentosa (RP), and venous occlusion, et al. Wide field OCT angiography images can be generated by montage scanning protocol based on the tracking system. OMAG algorithm based on complex differentiation was used to extract the blood flow and removed the bulk motion by 2D cross-correlation method. The 3D angiography was segmented into 3 layers in the retina and 2 layers in the choroid. The en-face maximum projection was used to obtain 2-dimensional angiograms of different layers coded with different colors. Flow and structure images were combined for cross-sectional view. En face OMAG images of different macular diseases showed a great agreement with FA. Meanwhile, OMAG gave more distinct vascular network visions that were less affected by hemorrhage and leakage. The MAs were observed in both superficial and middle retinal layers based on OMAG angiograms in different layers of DR patients. The contour line of FAZ was extracted as well, which can be quantitative the retinal diseases. For GA patient, the damage of RPE layer enhanced the penetration of light and enabled the acquisition of choriocapillaries and choroidal vessels. The wide field OMAG angiogram enabled the capability of capturing the entire geographic atrophy. OMAG provides depth-resolved information and detailed vascular images of DR and GA patients, providing a better visualization of vascular network compared to FA.

  18. A new rhodamine-based colorimetric chemosensor for naked-eye detection of Cu(2+) in aqueous solution.

    PubMed

    Hu, Yang; Zhang, Jing; Lv, Yuan-Zheng; Huang, Xiao-Huan; Hu, Sheng-li

    2016-03-15

    A new colorimetric probe 1 based on rhodamine B lactam was developed for naked-eye detection of Cu(2+). The optical feature of 1 for Cu(2+) was investigated by UV-vis absorption spectroscopy. Upon the addition of Cu(2+), the 1 displayed a distinct color change from colorless to pink, which can be directly detected by the naked eye. The stoichiometry of 1 to Cu(2+) complex was found to be 1:1 and the naked-eye detection limit was determined as low as 2 μM. The results suggest that the probe 1 may provide a convenient method for visual detection of Cu(2+) with high sensitivity.

  19. Eye blink correction: a test on the preservation of common ERP components using a regression based technique.

    PubMed

    Woltering, Steven; Bazargani, Narges; Liu, Zhong-Xu

    2013-01-01

    Eye blinks are a pervasive problem in electroencephalography research as they contaminate the brain signal. This paper tests the merits of a software tool employing the regression-based Gratton method that claims to remove the detrimental effects of the eye blink and leaves the activity of the brain. The efficacy of the correction tool was tested on five common stimulus-locked Event Related Potential (ERP) components used in a standard Go/Nogo task. Results suggested that the 'corrected' data could be predicted from data containing no eye blinks, suggesting the tool does not distort the data to great extent. This effect was found significant for all components, except for the P3. The conclusion is that this tool distorts the data at acceptable levels, yet caution should be taken when interpreting later components, like the P3.

  20. Eye blink correction: a test on the preservation of common ERP components using a regression based technique

    PubMed Central

    Bazargani, Narges; Liu, Zhong-Xu

    2013-01-01

    Eye blinks are a pervasive problem in electroencephalography research as they contaminate the brain signal. This paper tests the merits of a software tool employing the regression-based Gratton method that claims to remove the detrimental effects of the eye blink and leaves the activity of the brain. The efficacy of the correction tool was tested on five common stimulus-locked Event Related Potential (ERP) components used in a standard Go/Nogo task. Results suggested that the ‘corrected’ data could be predicted from data containing no eye blinks, suggesting the tool does not distort the data to great extent. This effect was found significant for all components, except for the P3. The conclusion is that this tool distorts the data at acceptable levels, yet caution should be taken when interpreting later components, like the P3. PMID:23682349

  1. A new rhodamine-based colorimetric chemosensor for naked-eye detection of Cu2 + in aqueous solution

    NASA Astrophysics Data System (ADS)

    Hu, Yang; Zhang, Jing; Lv, Yuan-Zheng; Huang, Xiao-Huan; Hu, Sheng-li

    2016-03-01

    A new colorimetric probe 1 based on rhodamine B lactam was developed for naked-eye detection of Cu2 +. The optical feature of 1 for Cu2 + was investigated by UV-vis absorption spectroscopy. Upon the addition of Cu2 +, the 1 displayed a distinct color change from colorless to pink, which can be directly detected by the naked eye. The stoichiometry of 1 to Cu2 + complex was found to be 1:1 and the naked-eye detection limit was determined as low as 2 μM. The results suggest that the probe 1 may provide a convenient method for visual detection of Cu2 + with high sensitivity.

  2. Is Making a Risky Choice Based on a Weighting and Adding Process? An Eye-Tracking Investigation

    ERIC Educational Resources Information Center

    Su, Yin; Rao, Li-Lin; Sun, Hong-Yue; Du, Xue-Lei; Li, Xingshan; Li, Shu

    2013-01-01

    The debate about whether making a risky choice is based on a weighting and adding process has a long history and is still unresolved. To address this long-standing controversy, we developed a comparative paradigm. Participants' eye movements in 2 risky choice tasks that required participants to choose between risky options in single-play and…

  3. Optic Disc Perfusion in Primary Open Angle and Normal Tension Glaucoma Eyes Using Optical Coherence Tomography-Based Microangiography

    PubMed Central

    Wen, Joanne C.; Zhang, Qinqin; Xin, Chen; Gupta, Divakar; Mudumbai, Raghu C.; Johnstone, Murray A.; Wang, Ruikang K.; Chen, Philip P.

    2016-01-01

    Purpose To investigate optic disc perfusion differences in normal, primary open-angle glaucoma (POAG), and normal tension glaucoma (NTG) eyes using optical microangiography (OMAG) based optical coherence tomography (OCT) angiography technique. Design Cross-sectional, observational study. Subjects Twenty-eight normal, 30 POAG, and 31 NTG subjects. Methods One eye from each subject was scanned with a 68 kHz Cirrus HD-OCT 5,000-based OMAG prototype system centered at the optic nerve head (ONH) (Carl Zeiss Meditec Inc, Dublin, CA). Microvascular images were generated from the OMAG dataset by detecting the differences in OCT signal between consecutive B-scans. The pre-laminar layer (preLC) was isolated by a semi-automatic segmentation program. Main Outcome Measures Optic disc perfusion, quantified as flux, vessel area density, and normalized flux (flux normalized by the vessel area) within the ONH. Results Glaucomatous eyes had significantly lower optic disc perfusion in preLC in all three perfusion metrics (p<0.0001) compared to normal eyes. The visual field (VF) mean deviation (MD) and pattern standard deviation (PSD) were similar between the POAG and NTG groups, and no differences in optic disc perfusion were observed between POAG and NTG. Univariate analysis revealed significant correlation between optic disc perfusion and VF MD, VF PSD, and rim area in both POAG and NTG groups (p≤0.0288). However, normalized optic disc perfusion was correlated with some structural measures (retinal nerve fiber layer thickness and ONH cup/disc ratio) only in POAG eyes. Conclusions Optic disc perfusion detected with OMAG was significantly reduced in POAG and NTG groups compared to normal controls, but no difference was seen between POAG and NTG groups with similar levels of VF damage. Disc perfusion was significantly correlated with VF MD, VF PSD, and rim area in glaucomatous eyes. Vascular changes at the optic disc as measured using OMAG may provide useful information for

  4. The benefit of Beam's eye view based 3D treatment planning for cervical cancer.

    PubMed

    Gerstner, N; Wachter, S; Knocke, T H; Fellner, C; Wambersie, A; Pötter, R

    1999-04-01

    The aim of this study was to evaluate the possibility of Beam's eye view (BEV) based three dimensional (3D) treatment planning, to reduce portions of organs at risk included in the treated volume without increasing the risk of geographical miss in external beam therapy of cervical cancer. Three dimensional dose distribution of BEV based 3D treatment plans was compared to the 3D dose distribution derived from a four-field-box-technique using standard portals. A total of 20 patients with cervical cancer stage FIGO IIB and FIGO IIIB was included. Dose distribution in the target volumes and in the organs at risk of BEV based treatment planning, was compared to the dose distribution of the standard field technique using dose-volume-histograms. In 4/20 patients (20%) a geographical miss at the cervix uteri was observed for the standard field technique. The BEV based treatment planning resulted in an adequate coverage of target volume and additionally in a reduction of portions of bladder and bowel volume included in the treated volume (-13.5, -10%). In contrast the BEV based technique resulted in an increase of portions of the rectum volume included in the treated volume compared to standard portals due to a shift of the rectum by the enlarged cervix uteri from its posterior to a lateral position. An overall 7% reduction of treated volume was observed, although the maximum width of lateral fields increased for the BEV technique. Moreover, we have found a remarkable impact of bladder fillings on the amount of bowel and bladder volume included in the treated volume. BEV based 3D treatment planning for external beam therapy of cervical cancer offers a possibility to avoid geographical miss of part of the CTV with reduced portions of bladder and bowel volume included in the treated volume.

  5. Correlation study in skin and eye irritation between rabbits and humans based on published literatures.

    PubMed

    Ishii, Satoko; Ishii, Kaori; Nakadate, Masahiro; Yamasaki, Kanji

    2013-05-01

    The purpose of this study was to investigate the correlations in skin and eye irritations between rabbits and humans using published international databases. We selected 60 and 56 compounds for skin and eye irritation, respectively. When the reactions were divided into irritation-negative or irritation-positive, including corrosion, similar reactions between rabbits and humans were detected for 53 compounds in skin irritation and 54 compounds in eye irritation, showing rates of agreement in skin and eye as 88% and 96%, respectively. These findings revealed that correlation in skin and eye irritations between rabbits and humans were high. However, corrosion was observed in rabbit skin treated with 14 compounds, 4 of which showed similar changes in humans, and in rabbit eyes treated with 9 compounds, 1 of which revealed similar changes in humans. These findings indicated that the incidence of corrosion was higher in rabbits than in humans. Our results showed that the data on rabbit irritations in the skin and eye were useful for identifying risk of irritation in human. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Neural bases of eye and gaze processing: The core of social cognition

    PubMed Central

    Itier, Roxane J.; Batty, Magali

    2014-01-01

    Eyes and gaze are very important stimuli for human social interactions. Recent studies suggest that impairments in recognizing face identity, facial emotions or in inferring attention and intentions of others could be linked to difficulties in extracting the relevant information from the eye region including gaze direction. In this review, we address the central role of eyes and gaze in social cognition. We start with behavioral data demonstrating the importance of the eye region and the impact of gaze on the most significant aspects of face processing. We review neuropsychological cases and data from various imaging techniques such as fMRI/PET and ERP/MEG, in an attempt to best describe the spatio-temporal networks underlying these processes. The existence of a neuronal eye detector mechanism is discussed as well as the links between eye gaze and social cognition impairments in autism. We suggest impairments in processing eyes and gaze may represent a core deficiency in several other brain pathologies and may be central to abnormal social cognition. PMID:19428496

  7. Eye detection based on head contour geometry and wavelet subband projection

    NASA Astrophysics Data System (ADS)

    Wang, Jing-Weing; Chen, Wen-Yuan

    2006-05-01

    We propose a novel two-step approach for eyes detection in complex scenes including both indoor and outdoor environments. This approach adopts face localization to eye extraction strategy. First, we use energy analysis to remove most noise-like regions to enhance face localization performance, and then use the head contour detection (HCD) approach to search for the best combinations of facial sides and head contours with an anthropometric measure, and thereafter the face-of-interest (FOI) region is located. In the meantime, via the deedging preprocessing for facial sides, a wavelet subband interorientation projection method is adopted to select eye-like candidates. Along with the geometric discrimination among the facial components, such as the eyes, nose, and mouth, this eye verification rule verifies the selected eyes candidates. The eye positions are then marked and refined by the bounding box of FOI region as the ellipse being the best fit of the facial oval shape. The experimental results demonstrate that the performance of our proposed method has significant improvement compared to others on three head-and-shoulder databases.

  8. The Effectiveness of Panoramic Maps Design: a Preliminary Study Based on Mobile Eye-Tracking

    NASA Astrophysics Data System (ADS)

    Balzarini, R.; Murat, M.

    2016-06-01

    This paper presents preliminary results from an ongoing research based on the study of visual attention through mobile eye-tracking techniques. The visual-cognitive approach investigates the reading-comprehension of a particular territorial representation: ski trails maps. The general issue of the study is to provide insights about the effectiveness of panoramic ski maps and more broadly, to suggest innovative efficient representation of the geographic information in mountain. According to some mountain operators, the information provided by paper ski maps no longer meets the needs of a large part of the customers; the question now arises of their adaptation to new digital practices (iPhone, tablets). In a computerized process perspective, this study particularly focuses on the representations, and the inferred information, which are really helpful to the users-skiers to apprehend the territory and make decisions, and which could be effectively replicated into a digital system. The most interesting output relies on the relevance of the panorama view: panorama still fascinates, but contrary to conventional wisdom, the information it provides does not seem to be useful to the skier. From a socio-historical perspective this study shows how empirical evidence-based approach can support the change: our results enhance the discussion on the effectiveness of the message that mountain operators want to convey to the tourist and therefore, on the renewal of (geographical) information in ski resorts.

  9. The Effect of Eye Fatigue on Reading, Based on Test Scores and the Presence of Deviant Eye Coordination, Either Esophoria, Exophoria or Hyperphoria.

    ERIC Educational Resources Information Center

    Gillis, George A.

    Studied were eye coordination and effects of fatigue on vision in the visual and academic functioning of 1049 students in grades 1 through 10. An earlier study (1966) examined the eye coordination of 1152 students in grades 1 through 12. The common Snellen Test of Visual Acuity failed to indicate 42% of students who were diagnosed by other tests…

  10. Quick-Eye: Examination of Human Performance Characteristics Using Eye Tracking and Manual-Based Control Systems for Monitoring Multiple Displays

    DTIC Science & Technology

    2013-03-01

    by using eye-tracking input instead of manual controls to switch control among multiple displays. 15. SUBJECT TERMS Eye tracking human - computer interaction interface...tracking has become an increasingly viable means of human - computer interaction . Specifically, those APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS...control methods; validate system performance against predictive models of human - computer interaction performance b. Relationship between response

  11. Updating OSHA Standards Based on National Consensus Standards; Eye and Face Protection. Final rule.

    PubMed

    2016-03-25

    On March 13, 2015, OSHA published in the Federal Register a notice of proposed rulemaking (NPRM) to revise its eye and face protection standards for general industry, shipyard employment, marine terminals, longshoring, and construction by updating the references to national consensus standards approved by the American National Standards Institute (ANSI). OSHA received no significant objections from commenters and therefore is adopting the amendments as proposed. This final rule updates the references in OSHA's eye and face standards to reflect the most recent edition of the ANSI/International Safety Equipment Association (ISEA) eye and face protection standard. It removes the oldest-referenced edition of the same ANSI standard. It also amends other provisions of the construction eye and face protection standard to bring them into alignment with OSHA's general industry and maritime standards.

  12. Looking at the aquatic contamination through fish eyes--a faithful picture based on metals burden.

    PubMed

    Pereira, Patrícia; Raimundo, Joana; Canário, João; Almeida, Armando; Pacheco, Mário

    2013-12-15

    This study describes for the first time metal accumulation in the eyes of native golden grey mullet (Liza aurata) coupled with water/sediment quality assessment. Sampling was performed in the Tagus estuary (Portugal) where a confined area (Barreiro) is severely contaminated by metal/loids. Levels of As, Cu, Pb, Hg and Cd in sediments from Barreiro were one order of magnitude higher than those from the reference site. Data on water column pointed also to a higher availability of Cu, Pb, Cd and Hg (including MeHg) at Barreiro. Accordingly, fish eyes accumulated higher levels of metal/loids at Barreiro than at the reference site. These findings support the use of fish eyes as a target organ in environmental health assessment since they reflect sediment and water contamination. It points also to the importance of evaluate eye changes at structural/functional levels in order to examine in what extent accumulated metals could compromise this perceptive system.

  13. Development of a Preference-Based Index from the National Eye Institute Visual Function Questionnaire-25

    PubMed Central

    Rentz, Anne M.; Kowalski, Jonathan W.; Walt, John G.; Hays, Ron D.; Brazier, John E.; Yu, Ren; Lee, Paul; Bressler, Neil; Revicki, Dennis A.

    2015-01-01

    Importance Understanding how individuals value health states is central to patient-centered care and to health policy decision making. Generic preference-based measures of health may not effectively capture the impact of ocular diseases. Recently, 6 items from the National Eye Institute Visual Function Questionnaire-25 were used to develop the Visual Function Questionnaire-Utility Index health state classification, which defines visual function health states. Objective To describe elicitation of preferences for health states generated from the Visual Function Questionnaire-Utility Index health state classification and development of an algorithm to estimate health preference scores for any health state. Design Non-intervention, cross-sectional study. Setting General community in four countries (Australia, Canada, United Kingdom, and United States) Participants 607 adult participants recruited from local newspaper advertisements. In the United Kingdom, an existing database of participants from previous studies was used for recruitment. Interventions Eight out of 15,625 possible health states from the Visual Function Questionnaire-Utility Index were valued using time trade-off technique. Main Outcome Measures A theta severity score was calculated for Visual Function Questionnaire-Utility Index–defined health states using item response theory analysis. Regression models were then used to develop an algorithm to assign health state preference values for all potential health states defined by the Visual Function Questionnaire-Utility Index. Results Health state preference values for the 8 states ranged from 0.343 (standard deviation, 0.395) to 0.956 (0.124). As expected, preference values declined with worsening visual function. Results indicate that the Visual Function Questionnaire-Utility Index describes states that participants view as spanning most of continuum from full health to dead. Conclusions and Relevance Visual Function Questionnaire-Utility Index health

  14. A novel biometric X-ray backscatter inspection of dangerous materials based on a lobster-eye objective

    NASA Astrophysics Data System (ADS)

    Xu, Jie; Wang, Xin; Mu, Baozhong; Zhan, Qi; Xie, Qing; Li, Yaran; Chen, Yifan; He, Yanan

    2016-10-01

    In order to counter drug-related crimes effectively, and to safeguard homeland security as well as public safety, it is important to inspect drugs, explosives and other contraband quickly and accurately from the express mail system, luggage, vehicles and other objects. In this paper, we discuss X-ray backscatter inspection system based on a novel lobster-eye X-ray objective, which is an effective inspection technology for drugs, explosives and other contraband inspection. Low atomic number materials, such as drugs and explosives, leads to strong Compton scattering after irradiated by X-ray, which is much stronger than high atomic number material, such as common metals, etc. By detecting the intensity of scattering signals, it is possible to distinguish between organics and inorganics. The lobster-eye X-ray optical system imitates the reflective eyes of lobsters, which field of view can be made as large as desired and it is practical to achieve spatial resolution of several millimeters for finite distance detection. A novel lobster-eye X-ray objective is designed based on modifying Schmidt geometry by using multi-lens structure, so as to reduce the difference of resolution between the horizontal and vertical directions. The demonstration experiments of X-ray backscattering imaging were carried out. A suitcase, a wooden box and a tire with several typical samples hidden in them were imaged by the X-ray backscattering inspection system based on a lobster-eye X-ray objective. The results show that this X-ray backscattering inspection system can get a resolution of less than five millimeters under the FOV of more than two hundred millimeters with 0.5 meter object distance, which can still be improved.

  15. Role of muscle pulleys in producing eye position-dependence in the angular vestibuloocular reflex: a model-based study

    NASA Technical Reports Server (NTRS)

    Thurtell, M. J.; Kunin, M.; Raphan, T.; Wall, C. C. (Principal Investigator)

    2000-01-01

    It is well established that the head and eye velocity axes do not always align during compensatory vestibular slow phases. It has been shown that the eye velocity axis systematically tilts away from the head velocity axis in a manner that is dependent on eye-in-head position. The mechanisms responsible for producing these axis tilts are unclear. In this model-based study, we aimed to determine whether muscle pulleys could be involved in bringing about these phenomena. The model presented incorporates semicircular canals, central vestibular pathways, and an ocular motor plant with pulleys. The pulleys were modeled so that they brought about a rotation of the torque axes of the extraocular muscles that was a fraction of the angle of eye deviation from primary position. The degree to which the pulleys rotated the torque axes was altered by means of a pulley coefficient. Model input was head velocity and initial eye position data from passive and active yaw head impulses with fixation at 0 degrees, 20 degrees up and 20 degrees down, obtained from a previous experiment. The optimal pulley coefficient required to fit the data was determined by calculating the mean square error between data and model predictions of torsional eye velocity. For active head impulses, the optimal pulley coefficient varied considerably between subjects. The median optimal pulley coefficient was found to be 0.5, the pulley coefficient required for producing saccades that perfectly obey Listing's law when using a two-dimensional saccadic pulse signal. The model predicted the direction of the axis tilts observed in response to passive head impulses from 50 ms after onset. During passive head impulses, the median optimal pulley coefficient was found to be 0.21, when roll gain was fixed at 0.7. The model did not accurately predict the alignment of the eye and head velocity axes that was observed early in the response to passive head impulses. We found that this alignment could be well predicted if

  16. Role of muscle pulleys in producing eye position-dependence in the angular vestibuloocular reflex: a model-based study

    NASA Technical Reports Server (NTRS)

    Thurtell, M. J.; Kunin, M.; Raphan, T.; Wall, C. C. (Principal Investigator)

    2000-01-01

    It is well established that the head and eye velocity axes do not always align during compensatory vestibular slow phases. It has been shown that the eye velocity axis systematically tilts away from the head velocity axis in a manner that is dependent on eye-in-head position. The mechanisms responsible for producing these axis tilts are unclear. In this model-based study, we aimed to determine whether muscle pulleys could be involved in bringing about these phenomena. The model presented incorporates semicircular canals, central vestibular pathways, and an ocular motor plant with pulleys. The pulleys were modeled so that they brought about a rotation of the torque axes of the extraocular muscles that was a fraction of the angle of eye deviation from primary position. The degree to which the pulleys rotated the torque axes was altered by means of a pulley coefficient. Model input was head velocity and initial eye position data from passive and active yaw head impulses with fixation at 0 degrees, 20 degrees up and 20 degrees down, obtained from a previous experiment. The optimal pulley coefficient required to fit the data was determined by calculating the mean square error between data and model predictions of torsional eye velocity. For active head impulses, the optimal pulley coefficient varied considerably between subjects. The median optimal pulley coefficient was found to be 0.5, the pulley coefficient required for producing saccades that perfectly obey Listing's law when using a two-dimensional saccadic pulse signal. The model predicted the direction of the axis tilts observed in response to passive head impulses from 50 ms after onset. During passive head impulses, the median optimal pulley coefficient was found to be 0.21, when roll gain was fixed at 0.7. The model did not accurately predict the alignment of the eye and head velocity axes that was observed early in the response to passive head impulses. We found that this alignment could be well predicted if

  17. Gain Control in Predictive Smooth Pursuit Eye Movements: Evidence for an Acceleration-Based Predictive Mechanism

    PubMed Central

    Eggert, Thomas

    2017-01-01

    Abstract The smooth pursuit eye movement system incorporates various control features enabling adaptation to specific tracking situations. In this work, we analyzed the interplay between two of these mechanisms: gain control and predictive pursuit. We tested human responses to high-frequency perturbations during step-ramp pursuit, as well as the pursuit of a periodically moving target. For the latter task, we found a nonlinear interaction between perturbation response and carrier acceleration. Responses to perturbations where the initial perturbation acceleration was contradirectional to carrier acceleration increased with carrier velocity, in a manner similar to that observed during step-ramp pursuit. In contrast, responses to perturbations with ipsidirectional initial perturbation and carrier acceleration were large for all carrier velocities. Modeling the pursuit system suggests that gain control and short-term prediction are separable elements. The observed effect may be explained by combining the standard gain control mechanism with a derivative-based short-term predictive mechanism. The nonlinear interaction between perturbation and carrier acceleration can be reproduced by assuming a signal saturation, which is acting on the derivative of the target velocity signal. Our results therefore argue for the existence of an internal estimate of target acceleration as a basis for a simple yet efficient short-term predictive mechanism. PMID:28560317

  18. Defragmented image based autostereoscopic 3D displays with dynamic eye tracking

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Kyu; Yoon, Ki-Hyuk; Yoon, Seon Kyu; Ju, Heongkyu

    2015-12-01

    We studied defragmented image based autostereoscopic 3D displays with dynamic eye tracking. Specifically, we examined the impact of parallax barrier (PB) angular orientation on their image quality. The 3D display system required fine adjustment of PB angular orientation with respect to a display panel. This was critical for both image color balancing and minimizing image resolution mismatch between horizontal and vertical directions. For evaluating uniformity of image brightness, we applied optical ray tracing simulations. The simulations took effects of PB orientation misalignment into account. The simulation results were then compared with recorded experimental data. Our optimal simulated system produced significantly enhanced image uniformity at around sweet spots in viewing zones. However this was contradicted by real experimental results. We offer quantitative treatment of illuminance uniformity of view images to estimate misalignment of PB orientation, which could account for brightness non-uniformity observed experimentally. Our study also shows that slight imperfection in the adjustment of PB orientation due to practical restrictions of adjustment accuracy can induce substantial non-uniformity of view images' brightness. We find that image brightness non-uniformity critically depends on misalignment of PB angular orientation, for example, as slight as ≤ 0.01 ° in our system. This reveals that reducing misalignment of PB angular orientation from the order of 10-2 to 10-3 degrees can greatly improve the brightness uniformity.

  19. Eye movements reveal the time-course of anticipating behaviour based on complex, conflicting desires.

    PubMed

    Ferguson, Heather J; Breheny, Richard

    2011-05-01

    The time-course of representing others' perspectives is inconclusive across the currently available models of ToM processing. We report two visual-world studies investigating how knowledge about a character's basic preferences (e.g. Tom's favourite colour is pink) and higher-order desires (his wish to keep this preference secret) compete to influence online expectations about subsequent behaviour. Participants' eye movements around a visual scene were tracked while they listened to auditory narratives. While clear differences in anticipatory visual biases emerged between conditions in Experiment 1, post-hoc analyses testing the strength of the relevant biases suggested a discrepancy in the time-course of predicting appropriate referents within the different contexts. Specifically, predictions to the target emerged very early when there was no conflict between the character's basic preferences and higher-order desires, but appeared to be relatively delayed when comprehenders were provided with conflicting information about that character's desire to keep a secret. However, a second experiment demonstrated that this apparent 'cognitive cost' in inferring behaviour based on higher-order desires was in fact driven by low-level features between the context sentence and visual scene. Taken together, these results suggest that healthy adults are able to make complex higher-order ToM inferences without the need to call on costly cognitive processes. Results are discussed relative to previous accounts of ToM and language processing.

  20. An iris localization algorithm based on geometrical features of cow eyes

    NASA Astrophysics Data System (ADS)

    Zhang, Menglu; Zhao, Lindu; Kong, Qiang

    2009-10-01

    Abrupt vicious affairs on meat food safety show rapid expansion, which poses a threat to food safety and human health. In order to trace the flow of meat products in the food supply chain, the research on the individual identification of large animals based on iris recognition has very important practical significance. Iris localization is the key step in the iris recognition system, and this paper makes the cow iris as an example to propose two-step localization method on the basis of studying and analyzing lots of cow geometrical features. Firstly, threshold transform and Sobel edge detection operator are used to make the image binarization processing and realize coarse location, and the coordinates of boundary points are determined with the quadratic B-spline interpolation curves. Secondly, the cow eye iris image is located from the coarseness to fine through fitting circles. This paper proposes two methods to determine the parameters of the inner and outer boundary circles, including fitting concentric and non-concentric circle. Experimental results show that fitting non-concentric circle algorithm can locate iris region quickly and efficiently and has better accuracy and good robustness.

  1. Your Eyes

    MedlinePlus

    ... the eye and keeps it healthy. previous continue Light, Lens, Action These next parts are really cool, ... the eye. previous continue Rods and Cones Process Light The retina uses special cells called rods and ...

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    ... News About Us Donate In This Section Eye Anatomy en Español email Send this article to a ... You at Risk For Glaucoma? Childhood Glaucoma Eye Anatomy Five Common Glaucoma Tests Glaucoma Facts and Stats ...

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    ... please turn Javascript on. Healthy Eyes Maintaining Your Vision Click for more information Taking good care of ... are qualified to perform eye exams. Aging and Vision Changes As you age, it is normal to ...

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    ... The Marfan Foundation Marfan & Related Disorders What is Marfan Syndrome? What are Related Disorders? What are the Signs? ... Emergencies Eye Emergencies Lung Emergencies Surgeries Eye Emergencies Marfan syndrome significantly increases your risk of retinal detachment, a ...

  6. Your Eyes

    MedlinePlus

    ... the eye and keeps it healthy. previous continue Light, Lens, Action These next parts are really cool, ... the eye. previous continue Rods and Cones Process Light The retina uses special cells called rods and ...

  7. The influence of crystalline lens accommodation on post-saccadic oscillations in pupil-based eye trackers.

    PubMed

    Nyström, Marcus; Andersson, Richard; Magnusson, Måns; Pansell, Tony; Hooge, Ignace

    2015-02-01

    It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate gaze direction from the location of the pupil. Since the size of the lens wobbles increases with accommodative effort, one would predict a similar increase of PSO-amplitude in data recorded with a pupil based eye tracker. In four experiments, we investigated the role of lens accommodation on PSOs in a video-based eye tracker. In Experiment 1, we replicated previous results showing that PSO-amplitudes increase at near viewing distances (large vergence angles), when the lens is highly accommodated. In Experiment 2a, we manipulated the accommodative state of the lens pharmacologically using eye drops at a fixed viewing distance and found, in contrast to Experiment 1, no significant difference in PSO-amplitude related to the accommodative state of the lens. Finally, in Experiment 2b, the effect of vergence angle was investigated by comparing PSO-amplitudes at near and far while maintaining a fixed lens accommodation. Despite the pharmacologically fixed degree of accommodation, PSO-amplitudes were systematically larger in the near condition. In summary, PSOs cannot exhaustively be explained by lens wobbles. Possible confounds related to pupil size and eye-camera angle are investigated in Experiments 3 and 4, and alternative mechanisms behind PSOs are probed in the discussion.

  8. A new measurement method for color discrimination thresholds of human eyes based on PWM light-mixing technology

    NASA Astrophysics Data System (ADS)

    Zhang, Jiyan; Dong, Jinxin

    2016-09-01

    The color discrimination is a powerful tool for detection of eye diseases, and it is is necessary to produce different kinds of color rapidly and precisely for testing color discrimination thresholds of human eyes. Three channels' pulse-width modulation (PWM) and light-mixing technology is a new way to mixing color, and a new measurement method for color discrimination thresholds of human eyes based on PWM light-mix technology can generate kinds of color stimuli. In this study, 5 youth volunteers were measured via this equipment after the test for the stability of the device's illumination and chrominance. Though the theory of Macadam ellipses and the interleaved staircase method, a psychophysical experiment was made to study the color discrimination threshold of the human eyes around a basic color center. By analyzing the data of the chromatic ellipse and the color discrimination threshold, the result shows that each color is not uniform in a single color region and the color difference threshold of normal human is around the third Macadam ellipses. The experimental results show that the repeatability and accuracy of the observer can meet the accuracy requirements of the relevant experiments, and the data is reliable and effective, which means the measurement method is an effective way to measure the color discrimination thresholds of human visual system.

  9. Self-reported comorbidities and visual function in a population-based study: the Los Angeles Latino Eye Study.

    PubMed

    Globe, Denise R; Varma, Rohit; Torres, Mina; Wu, Joanne; Klein, Ronald; Azen, Stanley P

    2005-06-01

    To assess the association of self-reported systemic and ocular comorbid disease and visual function in Latino subjects. National Eye Institute 25-item Visual Function Questionnaire (NEI-VFQ-25) and eye examination data were obtained from 5380 participants in the Los Angeles Latino Eye Study, a population-based prevalence study of eye disease in Latino subjects 40 years and older. We developed and contrasted 5 comorbidity measures. One-way analysis of variance was used to assess the association between comorbidity and visual impairment and self-reported visual function. Regression analyses determined the association of sociodemographic variables, clinical variables, and the best measure of comorbidity with the NEI-VFQ-25 composite score. The main outcome measure was self-reported visual function as assessed by the NEI-VFQ-25 composite score. On average, visual function subscale scores were lowest for those participants with the most systemic comorbid conditions (P<.05). This was more evident in participants with moderate or severe visual impairment compared with those with mild or no visual impairment (P<.05). Self-reported systemic comorbidities were associated with self-reported visual function. This association was greater at more severe levels of visual impairment. Of the 5 comorbidity measures assessed, the measure that summed the number of self-reported systemic comorbidities correlated most with self-reported visual function.

  10. [Software-based visualization of patient flow at a university eye clinic].

    PubMed

    Greb, O; Abou Moulig, W; Hufendiek, K; Junker, B; Framme, C

    2017-03-01

    This article presents a method for visualization and navigation of patient flow in outpatient eye clinics with a high level of complexity. A network-based software solution was developed targeting long-term process optimization by structural analysis and temporal coordination of process navigation. Each examination unit receives a separate waiting list of patients in which the patient flow for every patient is recorded in a timeline. Time periods and points in time can be executed by mouse clicks and the desired diagnostic procedure can be entered. Recent progress in any of these diagnostic requests, as well as a variety of information on patient progress are collated and drawn into the corresponding timeline which can be viewed by any of the personnel involved. The software called TimeElement has been successfully tested in the practical implemenation for several months. As an example the patient flow regarding time stamps of defined events for intravitreous injections on 250 patients was recorded and an average attendance time of 169.71 min was found, whereby the time was also automatically recorded for each individual stage. Recording of patient flow data is a fundamental component of patient flow management, waiting time reduction, patient flow navigation with time and coordination in particular regarding timeline-based visualization for each individual patient. Long-term changes in process management can be planned and evaluated by comparing patient flow data. As using the software itself causes structural changes within the organization, a questionnaire is being planned for appraisal by the personnel involved.

  11. Modeling of micro cat's eye retroreflectors using a matrix-based three-dimensional ray tracing technique.

    PubMed

    Yang, Bing-jun; Chao, Keng-hsing; Tsai, Jui-che

    2012-09-01

    In this paper we develop a three-dimensional (3D) ray tracing tool based on the ABCD ray transfer matrices. With symmetric optical components and under paraxial approximation, two sets of 2×2 ABCD matrices, each for a two-dimensional subspace, can be used to describe the 3D ray propagation completely. Compared to commercial ray-tracing software packages, our tool requires no tedious drawing, and the results for various conditions, such as different device dimensions and incident angles, can be easily obtained by simply changing the parameter values used for the calculation. We have employed this matrix-based 3D ray tracing tool to model cat's eye retroreflectors. The cat's eye performance, including the retroreflection efficiency, acceptance angle (i.e., field of view), and beam divergence and deviation, is fully studied. The application of this 3D ray tracing technique can be further extended to other optical components.

  12. A Model-Based Approach for the Measurement of Eye Movements Using Image Processing

    NASA Technical Reports Server (NTRS)

    Sung, Kwangjae; Reschke, Millard F.

    1997-01-01

    This paper describes a video eye-tracking algorithm which searches for the best fit of the pupil modeled as a circular disk. The algorithm is robust to common image artifacts such as the droopy eyelids and light reflections while maintaining the measurement resolution available by the centroid algorithm. The presented algorithm is used to derive the pupil size and center coordinates, and can be combined with iris-tracking techniques to measure ocular torsion. A comparison search method of pupil candidates using pixel coordinate reference lookup tables optimizes the processing requirements for a least square fit of the circular disk model. This paper includes quantitative analyses and simulation results for the resolution and the robustness of the algorithm. The algorithm presented in this paper provides a platform for a noninvasive, multidimensional eye measurement system which can be used for clinical and research applications requiring the precise recording of eye movements in three-dimensional space.

  13. What the human eye tells the brain: a new approach toward a hardware-based modeling of mental functions

    NASA Astrophysics Data System (ADS)

    Lauinger, N.

    2007-09-01

    A better understanding of intelligent information processing in human vision can be reached through a closer look at the macro- and micro-hardware available in the hierarchy of cortical processors along the main visual pathway connecting the retina, the CGL (corpus geniculatum laterale) and area V1 (cortical visual area 17). The building of the eye is driven by the brain and the engineering of the main visual pathway back to V1 seems to be driven by the eyes. The human eye offers to the brain much more intelligent information about the outer visible world than a camera producing flat 2D images on a CCD. Intelligent processing of visual information in human vision - a strong cooperation between eyes and brain - relays on axes related symmetry operations relevant for navigation in 4D spectral space-times, on a hierarchy of dynamically balanced equilibrium states, on diffractive-optical transformation of the Visible into RGB space, on range mapping based on RGB data (monocular and binocular 3D vision), on illuminant-adaptive optical correlations of local onto global RGB data (color constancy performances) and on invariant fourier-optical log-polar processing of image data (generic object classification; identification of objects). These performances are more compatible with optical processing of modern diffractive-optical sensors and interference-optical correlators than with cameras. The R+D project NAMIROS (Nano- and Micro-3D gratings for Optical Sensors) [8], coordinated by an interdisciplinary team of specialists at Corrsys 3D Sensors AG, describes the roadmap towards a technical realization of outstanding high-tech performances corresponding to human eye-brain co-processing.

  14. Distribution of conjunctival ultraviolet autoflourescence in a population-based study: the Norfolk Island Eye Study

    PubMed Central

    Sherwin, J C; Hewitt, A W; Kearns, L S; Coroneo, M T; Griffiths, L R; Mackey, D A

    2011-01-01

    Objective The objective of this study was to describe the distribution of conjunctival ultraviolet autofluorescence (UVAF) in an adult population. Methods We conducted a cross-sectional, population-based study in the genetic isolate of Norfolk Island, South Pacific Ocean. In all, 641 people, aged 15 to 89 years, were recruited. UVAF and standard (control) photographs were taken of the nasal and temporal interpalpebral regions bilaterally. Differences between the groups for non-normally distributed continuous variables were assessed using the Wilcoxon–Mann–Whitney ranksum test. Trends across categories were assessed using Cuzick's non-parametric test for trend or Kendall's rank correlation τ. Results Conjunctival UVAF is a non-parametric trait with a positively skewed distribution. Median amount of conjunctival UVAF per person (sum of four measurements; right nasal/temporal and left nasal/temporal) was 28.2 mm2 (interquartile range 14.5–48.2). There was an inverse, linear relationship between UVAF and advancing age (P<0.001). Males had a higher sum of UVAF compared with females (34.4 mm2 vs23.2 mm2, P<0.0001). There were no statistically significant differences in area of UVAF between right and left eyes or between nasal and temporal regions. Conclusion We have provided the first quantifiable estimates of conjunctival UVAF in an adult population. Further data are required to provide information about the natural history of UVAF and to characterise other potential disease associations with UVAF. UVR protective strategies should be emphasised at an early age to prevent the long-term adverse effects on health associated with excess UVR. PMID:21494284

  15. Optimization-based technique for separation and detection of saccadic movements and eye-blinking in electrooculography biosignals.

    PubMed

    Krupiński, Robert; Mazurek, Przemysław

    2011-01-01

    Electrooculography (EOG) gives the possibility of eye tracking using biosignal measurements. Typical EOG signal consists of rapid value changes (saccades) separated by almost constant values. Additionally, the pulse shape from eyelid blinking is observed. The separation of them is possible using numerous methods, like median filtering. The proposed optimization method based on a model fitting using the variable number of parameters gives the possibility of features localization even for nearby saccades and blinking pulses.

  16. Towards Quantum Experiments with Human Eye Detectors Based on Cloning via Stimulated Emission ?

    NASA Astrophysics Data System (ADS)

    De Martini, Francesco

    2010-05-01

    In a recent theoretical paper published in Physical Review Letters, Sekatsky, Brunner, Branciard, Gisin, Simon report an extended investigation on some properties of the human eye that affect its behavior as a quantum detector. We believe that the content of this work, albeit appealing at fist sight, is highly questionable simply because the human eye cannot be adopted as a sensing device within any quantum measurement apparatus. Furthermore, the criticism raised by these Authors against a real experiment on Micro—Macro entanglement recently published in Physical Review Letters (100, 253601, 2008) is found misleading and misses its target.

  17. Behavioural and eye-movement outcomes in response to text-based reading treatment for acquired alexia.

    PubMed

    Kim, Esther S; Lemke, Shannon F

    2016-01-01

    Text-based reading treatments, such as Multiple Oral Rereading (MOR) and Oral Reading for Language in Aphasia (ORLA) have been used successfully to remediate reading impairments in individuals with acquired alexia, but the mechanisms underlying such improvements are not well understood. In this study, an individual with acquired alexia who demonstrated reliance on a sub-lexical reading strategy (i.e., presence of spelling regularity effect and phonologically plausible errors) underwent 12 weeks of text-based reading treatment combining MOR and ORLA procedures. Behavioural assessments of single-word and text reading, along with eye-tracking assessments were conducted pre-treatment, post-treatment and at 5 month follow-up. Improved reading fluency (rate, accuracy) was observed for both trained and untrained passages. Evidence from behavioural and eye-tracking assessment suggested text-based reading treatment facilitated use of a lexical-semantic reading strategy. Increased frequency and lexicality effects, as well as a shift in initial landing position towards the centre of the word (the "optimal viewing position") were observed at post-treatment and follow-up assessments. These results demonstrate the potential utility of using eye movements as a parameter of interest in addition to traditional behavioural outcomes when investigating response to reading treatment.

  18. High-sensitive and high-efficient biochemical analysis method using a bionic electronic eye in combination with a smartphone-based colorimetric reader system.

    PubMed

    Kaiqi Su; Quchao Zou; Ning Hu; Ping Wang

    2015-01-01

    Bionic electronic eye (Bionic e-Eye), a developed smartphone-based colorimetric reader system, consists of smartphone or pad (iPhone 4s or iPad 3) as detection instrument and portable accessory as illumination provider, integrating with a wide-angle lens, a piece of lowest-power electro luminescent and a custom-made dark hood. A 96-well microtiter plate (MTP) was positioned on the electro luminescent and Bionic e-Eye captures the detection images by the back camera of smartphone. Being similar to human visual system, the hue, saturation and value (HSV, also called hex cone model) color model was employed in image processing algorithm of Bionic e-Eye. Optimized system dimension was determined by the system steadiness experiment of different photograph distances. Moreover, the commercially available BCA protein assay and CCK8 cell number assay were carried out to evaluate this Bionic e-Eye. Analytical performance of Bionic e-Eye had the better precision, higher sensitivity than microtiter plate reader (MTPR) and previous smartphone-based colorimetric reader for both two assays. Also, Bionic e-Eye using optical image detection had simultaneous and synchronous working mode, while MPTR using machine moving detection had asynchronous working mode in high throughput detection. Therefore, Bionic e-Eye will be an ideal point-of-care (POC) colorimetric detection device in the field of clinical application, industrial quality control, environment monitoring, and food assessment.

  19. Advanced Clinical Imaging and Tissue-based Biomarkers of the Eye for Toxicology Studies in Minipigs.

    PubMed

    Atzpodien, Elke-Astrid; Jacobsen, Bjoern; Funk, Juergen; Altmann, Bernd; Silva Munoz, Manuel A; Singer, Thomas; Gyger, Cyrill; Hasler, Pascal; Maloca, Peter

    2016-04-01

    There is increased interest to use minipigs in ocular toxicology studies due to their anatomical similarities with human eyes and as a substitute for nonhuman primates. This requires adaptation of enhanced optical coherence tomography (OCT) techniques and of ocular relevant immunohistochemistry (IHC) or in situ hybridization (ISH) markers to porcine eyes. In this study, OCT and OCT angiography (AngioOCT) were performed on adult Göttingen minipigs. To increase structural information on retinal and choroidal vasculature, OCT data were speckle denoized and choroidal blood vessels were segmented with threshold filtering. In addition, we established a set of IHC and ISH markers on Davidson's fixed paraffin-embedded minipig eyes: neurofilament-160, neuronal nuclei, calretinin, protein kinase C-α, vimentin, glial fibrillary acidic protein, glutamine synthetase, ionized calcium-binding adaptor molecule-1, rhodopsin, synaptophysin, postsynaptic density protein-95, retinal pigment epithelium (RPE)-specific protein-65, von Willebrand factor, α-smooth muscle actin, desmin, and Ki-67, thus enabling visualization of retinal neuronal and glial cells, photoreceptors, synapses, RPE, blood vessels, myocytes, macrophages, or cell proliferation. Using ISH, transcripts of vascular endothelial growth factor A, angiopoietin-2, and endothelial tyrosine kinase were visualized. This article describes for the first time in minipig eyes speckle noise-free OCT, AngioOCT, and a set of IHC/ISH markers on Davidson's fixed paraffin-embedded tissues and helps to establish the minipig for ocular toxicology and pharmacology studies.

  20. Eye-tracking-based assessment of cognitive function in low-resource settings

    PubMed Central

    Forssman, Linda; Ashorn, Per; Ashorn, Ulla; Maleta, Kenneth; Matchado, Andrew; Kortekangas, Emma; Leppänen, Jukka M

    2017-01-01

    Background Early development of neurocognitive functions in infants can be compromised by poverty, malnutrition and lack of adequate stimulation. Optimal management of neurodevelopmental problems in infants requires assessment tools that can be used early in life, and are objective and applicable across economic, cultural and educational settings. Objective and design The present study examined the feasibility of infrared eye tracking as a novel and highly automated technique for assessing visual-orienting and sequence-learning abilities as well as attention to facial expressions in young (9-month-old) infants. Techniques piloted in a high-resource laboratory setting in Finland (N=39) were subsequently field-tested in a community health centre in rural Malawi (N=40). Results Parents' perception of the acceptability of the method (Finland 95%, Malawi 92%) and percentages of infants completing the whole eye-tracking test (Finland 95%, Malawi 90%) were high, and percentages of valid test trials (Finland 69–85%, Malawi 68–73%) satisfactory at both sites. Test completion rates were slightly higher for eye tracking (90%) than traditional observational tests (87%) in Malawi. The predicted response pattern indicative of specific cognitive function was replicated in Malawi, but Malawian infants exhibited lower response rates and slower processing speed across tasks. Conclusions High test completion rates and the replication of the predicted test patterns in a novel environment in Malawi support the feasibility of eye tracking as a technique for assessing infant development in low-resource setting. Further research is needed to the test–retest stability and predictive validity of the eye-tracking scores in low-income settings. PMID:27551061

  1. Eye-tracking-based assessment of cognitive function in low-resource settings.

    PubMed

    Forssman, Linda; Ashorn, Per; Ashorn, Ulla; Maleta, Kenneth; Matchado, Andrew; Kortekangas, Emma; Leppänen, Jukka M

    2017-04-01

    Early development of neurocognitive functions in infants can be compromised by poverty, malnutrition and lack of adequate stimulation. Optimal management of neurodevelopmental problems in infants requires assessment tools that can be used early in life, and are objective and applicable across economic, cultural and educational settings. The present study examined the feasibility of infrared eye tracking as a novel and highly automated technique for assessing visual-orienting and sequence-learning abilities as well as attention to facial expressions in young (9-month-old) infants. Techniques piloted in a high-resource laboratory setting in Finland (N=39) were subsequently field-tested in a community health centre in rural Malawi (N=40). Parents' perception of the acceptability of the method (Finland 95%, Malawi 92%) and percentages of infants completing the whole eye-tracking test (Finland 95%, Malawi 90%) were high, and percentages of valid test trials (Finland 69-85%, Malawi 68-73%) satisfactory at both sites. Test completion rates were slightly higher for eye tracking (90%) than traditional observational tests (87%) in Malawi. The predicted response pattern indicative of specific cognitive function was replicated in Malawi, but Malawian infants exhibited lower response rates and slower processing speed across tasks. High test completion rates and the replication of the predicted test patterns in a novel environment in Malawi support the feasibility of eye tracking as a technique for assessing infant development in low-resource setting. Further research is needed to the test-retest stability and predictive validity of the eye-tracking scores in low-income settings. 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/.

  2. A novel attention training paradigm based on operant conditioning of eye gaze: Preliminary findings.

    PubMed

    Price, Rebecca B; Greven, Inez M; Siegle, Greg J; Koster, Ernst H W; De Raedt, Rudi

    2016-02-01

    Inability to engage with positive stimuli is a widespread problem associated with negative mood states across many conditions, from low self-esteem to anhedonic depression. Though attention retraining procedures have shown promise as interventions in some clinical populations, novel procedures may be necessary to reliably attenuate chronic negative mood in refractory clinical populations (e.g., clinical depression) through, for example, more active, adaptive learning processes. In addition, a focus on individual difference variables predicting intervention outcome may improve the ability to provide such targeted interventions efficiently. To provide preliminary proof-of-principle, we tested a novel paradigm using operant conditioning to train eye gaze patterns toward happy faces. Thirty-two healthy undergraduates were randomized to receive operant conditioning of eye gaze toward happy faces (train-happy) or neutral faces (train-neutral). At the group level, the train-happy condition attenuated sad mood increases following a stressful task, in comparison to train-neutral. In individual differences analysis, greater physiological reactivity (pupil dilation) in response to happy faces (during an emotional face-search task at baseline) predicted decreased mood reactivity after stress. These Preliminary results suggest that operant conditioning of eye gaze toward happy faces buffers against stress-induced effects on mood, particularly in individuals who show sufficient baseline neural engagement with happy faces. Eye gaze patterns to emotional face arrays may have a causal relationship with mood reactivity. Personalized medicine research in depression may benefit from novel cognitive training paradigms that shape eye gaze patterns through feedback. Baseline neural function (pupil dilation) may be a key mechanism, aiding in iterative refinement of this approach. (c) 2016 APA, all rights reserved).

  3. Eye development.

    PubMed

    Baker, Nicholas E; Li, Ke; Quiquand, Manon; Ruggiero, Robert; Wang, Lan-Hsin

    2014-06-15

    The eye has been one of the most intensively studied organs in Drosophila. The wealth of knowledge about its development, as well as the reagents that have been developed, and the fact that the eye is dispensable for survival, also make the eye suitable for genetic interaction studies and genetic screens. This article provides a brief overview of the methods developed to image and probe eye development at multiple developmental stages, including live imaging, immunostaining of fixed tissues, in situ hybridizations, and scanning electron microscopy and color photography of adult eyes. Also summarized are genetic approaches that can be performed in the eye, including mosaic analysis and conditional mutation, gene misexpression and knockdown, and forward genetic and modifier screens.

  4. Liquid Crystal based adaptive optics system to compensate both low and high order aberrations in a model eye

    NASA Astrophysics Data System (ADS)

    Mu, Quanquan; Cao, Zhaoliang; Li, Dayu; Hu, Lifa; Xuan, Li

    2007-02-01

    Based on a simple eye model system, a high resolution adaptive optics retina imaging system was built to demonstrate the availability of using liquid crystal devices as a wave-front corrector for both low and high order aberrations. Myopia glass was used to introduce large low order aberrations. A fiber bundle was used to simulate the retina. After correction, its image at different diopters became very clear. We can get a root mean square (RMS) correction precision of lower than 0.049λ (λ=0.63μm) for over to 10 diopters and the modulation transfer function (MTF) retains 511p/mm, which is nearly the diffraction limited resolution for a 2.7mm pupil diameter. The closed loop bandwidth was nearly 4 Hz, which is capable to track most of the aberration dynamics in a real eye.

  5. Ancient mechanisms of visual sense organ development based on comparison of the gene networks controlling larval eye, ocellus, and compound eye specification in Drosophila.

    PubMed

    Friedrich, Markus

    2006-12-01

    Key mechanisms of development are strongly constrained, and hence often shared in the formation of highly diversified homologous organs. This diagnostic is applied to uncovering ancient gene activities in the control of visual sense organ development by comparing the gene networks, which regulate larval eye, ocellus and compound eye specification in Drosophila. The comparison reveals a suite of shared aspects that are likely to predate the diversification of arthropod visual sense organs and, consistent with this, have notable similarities in the developing vertebrate visual system: (I) Pax-6 genes participate in the patterning of primordia of complex visual organs. (II) Primordium determination and differentiation depends on formation of a transcription factor complex that contains the products of the selector genes Eyes absent and Sine oculis. (III) The TGF-beta signaling factor Decapentaplegic exerts transcriptional activation of eyes absent and sine oculis. (IV) Canonical Wnt signaling contributes to primordium patterning by repression of eyes absent and sine oculis. (V) Initiation of determination and differentiation is controlled by hedgehog signaling. (VI) Egfr signaling drives retinal cell fate specification. (VII) The proneural transcription factor atonal regulates photoreceptor specification. (VII) The zinc finger gene glass regulates photoreceptor specification and differentiation.

  6. Relationship Between Peripapillary Choroid and Retinal Nerve Fiber Layer Thickness in a Population-Based Sample of Nonglaucomatous Eyes.

    PubMed

    Gupta, Preeti; Cheung, Carol Y; Baskaran, Mani; Tian, Jing; Marziliano, Pina; Lamoureux, Ecosse L; Cheung, Chui Ming Gemmy; Aung, Tin; Wong, Tien Yin; Cheng, Ching-Yu

    2016-01-01

    To describe the relationship between peripapillary choroidal thickness and retinal nerve fiber layer (RNFL) thickness in a population-based sample of nonglaucomatous eyes. Population-based, cross-sectional study. A total of 478 nonglaucomatous subjects aged over 40 years were recruited from the Singapore Malay Eye Study (SiMES-2). All participants underwent a detailed ophthalmic examination, including Cirrus and Spectralis optical coherence tomography (OCT) for the measurements of RNFL thickness and peripapillary choroidal thickness, respectively. Associations between peripapillary choroidal thickness and RNFL thickness were assessed using linear regression models with generalized estimating equations. Of the 424 included subjects (843 nonglaucomatous eyes), 60.9% were women, and the mean (SD) age was 66.74 (10.44) years. The mean peripapillary choroidal thickness was 135.59 ± 56.74 μm and the mean RNFL thickness was 92.92 ± 11.41 μm. In terms of distribution profile, peripapillary choroid was thickest (150.04 ± 59.72 μm) at the superior and thinnest (110.71 ± 51.61 μm) at the inferior quadrant, whereas RNFL was thickest (118.60 ± 19.83 μm) at the inferior and thinnest (67.36 ± 11.36 μm) at the temporal quadrant. We found that thinner peripapillary choroidal thickness (PPCT) was independently associated with thinner RNFL thickness globally (regression coefficient [β] = -1.334 μm for per-SD decrease in PPCT, P = .003), and in the inferior (β = -2.565, P = .001) and superior (β = -2.340, P = .001) quadrants even after adjusting for potential confounders. Thinner peripapillary choroid was independently associated with thinner RNFL globally and in the inferior and superior regions. This structure-structure relationship may need further exploration in glaucomatous eyes prior to its application in clinical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. ADAPTIVE EYE MODEL - Poster Paper

    NASA Astrophysics Data System (ADS)

    Galetskiy, Sergey O.; Kudryashov, Alexey V.

    2008-01-01

    We propose experimental adaptive eye model based on flexible 18-electrode bimorph mirror reproducing human eye aberrations up to 4th radial order of Zernike polynomials at frequency of 10Hz. The accuracy of aberrations reproduction in most cases is better than λ/10 RMS. The model is introduced to aberrometer for human eye aberrations compensation to improve visual acuity test.

  8. Diabetes eye exams

    MedlinePlus

    Diabetic retinopathy - eye exams; Diabetes - eye exams; Glaucoma - diabetic eye exam; Macular edema - diabetic eye exam ... if the doctor who takes care of your diabetes checks your eyes, you need an eye exam ...

  9. Dissociating spatial and letter-based word length effects observed in readers' eye movement patterns.

    PubMed

    Hautala, Jarkko; Hyönä, Jukka; Aro, Mikko

    2011-08-01

    In previous eye movement research on word length effects, spatial width has been confounded with the number of letters. McDonald (2006) unconfounded these factors by rendering all words in sentences in constant spatial width. In the present study, the Arial font with proportional letter spacing was used for varying the number of letters while equating for spatial width, while the Courier font with monospaced letter spacing was used to measure the contribution of spatial width to the observed word length effect. Number of letters in words affected single fixation duration on target words, whereas words' spatial width determined fixation locations in words and the probability of skipping a word. The results support the existence of distinct subsystems for deciding where and when to move eyes in text (Rayner & McConkie, 1976). The number-of-letters effect in fixation duration may be explained by visual acuity, visual crowding, and/or serial letter processing.

  10. Indian Soldiers Need Eye Protection

    PubMed Central

    2017-01-01

    Combat-related eye injuries entail enormous financial, social and psychological cost. Military Combat Eye Protection (MCEP) decreases both the incidence and severity of eye injuries. Experts have recognised the need for MCEP for Indian soldiers. We aim to review the combat-related eye injuries and combat eye protection among the Indian soldiers. Global practices of MCEP are also reviewed. We also aim to offer our recommendations for Indian soldiers. We carried out Medline search for combat-related eye injuries and MCEP and separately searched for eye injuries among Indian soldiers during war and other operations. We present the findings as results. Recommendations are based on the opinions of the experts. Combat-related eye injuries increased from 3% of injured in the 1965 Indo-Pakistan War to 4.8% in 1971 war. During peace-keeping operations in Sri Lanka (1987-89) eye injuries increased to 10.5% of the injured. Statistics on eye injuries during counterinsurgency operations are not available. MCEP have shown reduction in eye injuries, and thus MCEP forms a part of personal equipment of the soldiers in developed countries. Indian soldiers do not have provision of MCEP. Combat-related eye injuries among Indian Army soldiers have been increasing. Data on eye injuries during counterinsurgency operations are not available. Indian soldiers do not have provision of MCEP. Provision of MCEP is therefore desirable. Awareness program among the commanders and the soldiers shall result in attitudinal changes and increased compliance. PMID:28384904

  11. Awareness of Glaucoma and Eye Health Services Among Faith-based Communities in Kumasi, Ghana.

    PubMed

    Murdoch, Calum; Opoku, Kennedy; Murdoch, Ian

    2016-10-01

    To determine awareness of glaucoma, "hinta anifraye" and available eye health services among urban communities in Kumasi, Ghana. "Hinta anifraye" is a recently developed term for glaucoma in the local Twi language. Convenience sampling was used to survey the communities of 4 churches and 2 mosques in Kumasi, recruiting participants as they arrived to attend religious services. Ten interviewers collected data by quantitative, interviewer-administered questionnaires. An awareness grading system was devised to categorize participant knowledge from level 0 to 4. Of a total 484 respondents, 269 (56%; 95% confidence interval, 52%-60%) had heard of glaucoma, and 284 (60%; 95% confidence interval, 56%-64%) had heard of either glaucoma or hinta anifraye. Only 142 (29%) had disease-specific knowledge of symptoms or causes. TV and radio were the main reported sources of information. Education, religious community, English language, male sex, and older age were all found to be significant indicators of awareness, with education shown to be a key confounding factor. Overall 436 (90%) mentioned either a hospital or doctor as a place they knew they could seek help for an eye problem. Awareness of glaucoma is higher than previously suggested from similar studies, but still very low from a global perspective. The findings suggest that media is a useful tool in disseminating health messages. Awareness of professional care was found to be remarkably high. Eye health promotion is recommended to raise awareness of glaucoma among this population.

  12. An acoustic Maxwell’s fish-eye lens based on gradient-index metamaterials

    NASA Astrophysics Data System (ADS)

    Yuan, Bao-guo; Tian, Ye; Cheng, Ying; Liu, Xiao-jun

    2016-10-01

    We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging. Project supported by the National Basic Research Program of China (Grant No. 2012CB921504), the National Natural Science Foundation of China (Grant Nos. 11574148, 11474162, 1274171, 11674172, and 11674175), and the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant Nos. 20110091120040 and 20120091110001).

  13. Eye Health

    PubMed Central

    Connell, A. M. S.

    1988-01-01

    The status of eye care in the Caribbean is discussed. Methods of primary eye care providers at all levels from primary to tertiary in the region are presented against a background of the major causes of blindness, cataract, glaucoma, and diabetic retinopathy. Epidemiological surveys examining prevalence, risk factors, and intervention programs are being undertaken. PMID:3404562

  14. Eyes - bulging

    MedlinePlus

    ... emotional support is important. When to Contact a Medical Professional Call your health care provider if: You have bulging eyes and the cause has not yet been diagnosed. Bulging eyes are accompanied by other symptoms. ... The provider will ask about your medical history and do a physical exam. Some questions ...

  15. 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…

  16. 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…

  17. Personal identification by eyes.

    PubMed

    Marinović, Dunja; Njirić, Sanja; Coklo, Miran; Muzić, Vedrana

    2011-09-01

    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems.

  18. Optical performance simulation of free-form optics for an eye implant based on a measurement data enhanced model.

    PubMed

    Sieber, Ingo; Li, Likai; Gengenbach, Ulrich; Beckert, Erik; Steinkopf, Ralf; Yi, Allen Y

    2016-08-20

    This paper describes the application of a modeling approach for precise optical performance prediction of free-form optics-based subsystems on a demonstration model of an eye implant. The simulation model is enhanced by surface data measured on the free-form lens parts. The manufacturing of the free-form lens parts is realized by two different manufacturing processes: ultraprecision diamond machining and microinjection molding. Evaluation of both processes is conducted by a simulation of the optical performance on the basis of their surface measurement comparisons with the nominal geometry. The simulation results indicate that improvements from the process optimization of microinjection molding were obtained for the best manufacturing accuracy.

  19. Metamaterial-based half Maxwell fish-eye lens for broadband directive emissions

    NASA Astrophysics Data System (ADS)

    Dhouibi, Abdallah; Nawaz Burokur, Shah; de Lustrac, André; Priou, Alain

    2013-01-01

    The broadband directive emission from a metamaterial surface is numerically and experimentally reported. The metasurface, composed of non-resonant complementary closed ring structures, is designed to obey the refractive index of a half Maxwell fish-eye lens. A planar microstrip Vivaldi antenna is used as transverse magnetic polarized wave launcher for the lens. A prototype of the lens associated with its feed structure has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Measurements agree quantitatively and qualitatively with theoretical simulations.

  20. Towards Quantum Experiments with Human Eyes as Detectors Based on Cloning via Stimulated Emission

    NASA Astrophysics Data System (ADS)

    Sekatski, Pavel; Brunner, Nicolas; Branciard, Cyril; Gisin, Nicolas; Simon, Christoph

    2009-09-01

    We show theoretically that a large Bell inequality violation can be obtained with human eyes as detectors, in a “micro-macro” experiment where one photon from an entangled pair is greatly amplified via stimulated emission. The violation is robust under photon loss. This leads to an apparent paradox, which we resolve by noting that the violation proves the existence of entanglement before the amplification. The same is true for the micro-macro experiments performed so far with conventional detectors. However, we also prove that there is genuine micro-macro entanglement even for high loss.

  1. Interactions between landscape elements and tranquility evaluation based on eye tracking experiments (L).

    PubMed

    Ren, Xinxin; Kang, Jian

    2015-11-01

    Visual attention in tranquility evaluations has been examined by eye tracking experiments using audiovisual materials collected in traditional villages of China. The results show that without sound stimuli, the attention areas in tranquility evaluations are more concentrated, compared with those in visual aesthetic quality evaluations. With sound stimuli, the attention areas of tranquility evaluations disperse significantly from those without sound stimuli, where artificial sounds tend to expand the visual attention area on corresponding artificial landscape elements, whereas natural sounds promote larger attention areas on natural landscape elements. During information extraction for tranquility evaluations, both with and without sound stimuli, buildings and facilities, the sky, and vegetation are attractive landscape elements.

  2. Analysis of sharpness Fano resonance curve based on eye-like resonators

    NASA Astrophysics Data System (ADS)

    Lou, Xiao-wei; Cui, Jin-jiang; Dong, Ning-ning; Xu, Jian-gen; Tan, Hui-ming

    2014-11-01

    For given intrinsic losses of a single ring resonator sensor, there exists the maximum sharpness, at the extinction ratio of -6dB. However, the maximum sharpness of a single ring resonator sensor is sensitive for the coupling coefficient. In order to obtain the maximum sharpness, the coupling region of the single rings must have a higher precision of manufacture. To solve this problem, this paper proposed eye-like resonator which is formed by a ring resonator (named inner loop) embedd in the dual-bus-coupled ring resonator (named outer loop). Eye-like resonators can generate the asymmetric Fano-resonance spectra of the drop port, numerical calculation of spectra on the drop port is utilized by the transfer matrix method. As the round trip loss varies, the maximum value of sharpness and the corresponding transmission at the resonant point can be obtained by tuning the phase ratio of the outer loop to the inner loop. The maximum value of sharpness increases with the round trip loss, as the outer loop and inner loop coupling coefficient changing, the maximum value of sharpness of Fano-resonance change slowly in a wide range. As the round trip loss and coupling coefficients of the outer loop and inner loop varies, the corresponding transmission at the resonant point remains almost the same, about -6dB. The sharpness of Fano resonant peak is insensitive for the coupling coefficients, which can reduce the requirements of manufacture of coupling region.

  3. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit.

    PubMed

    Mahdipour, Seyed Ali; Mowlavi, Ali Asghar

    2016-01-01

    Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth-dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8MeV proton, 190.1MeV alpha, and 1060MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam׳s Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owing to the beam broadening caused by scattering, can be a good choice for the large-size tumors.

  4. Linear fitting interpolation based on FOV division for correcting wide angle fish-eye lens distortion

    NASA Astrophysics Data System (ADS)

    Li, An; Wu, Yi-si; Chen, Chi; Zheng, Zhen-rong

    2015-09-01

    The wide angle lens, like fish eye lens, suffers great optical distortion that causes severe deformation of the real world. A method to correct the strong distortion was presented in this work. Due to the nonlinear distribution of the distortion, linear algorithms are generally not under consideration to establish the math model of distorted-to-ideal images. However, this method employed the calibration pattern that comprised of regular array of dots to divides the full field of view (FOV) to subsections, each subsection is a small FOV, the mapping parameters between the distorted image and ideal image in each small FOV can be calculated by employing the very simple linear polynomial. Thus, applying the determined parameters to their corresponding sub-FOVs, respectively, all the ideal pixel coordinates of the distorted image can be obtained. The method employed linear polynomial characterizes the geometric deformation between the distorted and ideal images directly. Therefore, it contains both of radial distortion and tangential distortion and there is no need of concerning any intrinsic or extrinsic parameters of the optical systems. So, this algorithm reliefs the computational work that employed by conventional radial models and other mathematical models. Experiments performed on off-axis optical systems which exist complicated distortion, such as the head mounted displays (HMDs), had already yielded accurate correcting results. Likewise, in this paper, the experiments refer to the fish-eye lens also verify the effectiveness and flexibility of this method, as well, high correcting accuracy is achieved.

  5. Ion therapy for uveal melanoma in new human eye phantom based on GEANT4 toolkit

    SciTech Connect

    Mahdipour, Seyed Ali; Mowlavi, Ali Asghar

    2016-07-01

    Radiotherapy with ion beams like proton and carbon has been used for treatment of eye uveal melanoma for many years. In this research, we have developed a new phantom of human eye for Monte Carlo simulation of tumors treatment to use in GEANT4 toolkit. Total depth−dose profiles for the proton, alpha, and carbon incident beams with the same ranges have been calculated in the phantom. Moreover, the deposited energy of the secondary particles for each of the primary beams is calculated. The dose curves are compared for 47.8 MeV proton, 190.1 MeV alpha, and 1060 MeV carbon ions that have the same range in the target region reaching to the center of tumor. The passively scattered spread-out Bragg peak (SOBP) for each incident beam as well as the flux curves of the secondary particles including neutron, gamma, and positron has been calculated and compared for the primary beams. The high sharpness of carbon beam's Bragg peak with low lateral broadening is the benefit of this beam in hadrontherapy but it has disadvantages of dose leakage in the tail after its Bragg peak and high intensity of neutron production. However, proton beam, which has a good conformation with tumor shape owing to the beam broadening caused by scattering, can be a good choice for the large-size tumors.

  6. Black Eye

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  7. Eye Symptoms

    MedlinePlus

    ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  8. Eye Infections

    MedlinePlus

    ... become red, he probably has a condition called conjunctivitis . Also known as pinkeye, this inflammation, which can be painful and itchy, ... bacteria, antibiotic eye drops are the usual treatment. Conjunctivitis caused by viruses should not be treated with ...

  9. Are higher blood mercury levels associated with dry eye symptoms in adult Koreans? A population-based cross-sectional study

    PubMed Central

    Chung, So-Hyang

    2016-01-01

    Objectives The purpose of this study was to investigate whether blood mercury concentrations associated with the presence of dry eye symptoms in a nationally representative Korean population. Methods Population-based prospective cross-sectional study using the heavy metal data set of the 2010–2012 Korean National Health and Nutrition Examination Survey (KNHANES). A total of 4761 adult Koreans were the eligible population in this study. Of the 7162 survey participants, 2401 were excluded because they were <19 years of age, there were missing data in the heavy metal data set, or they had diabetes, rheumatoid arthritis, thyroid disease, asthma, depression and/or under-the-eye surgery. Blood mercury levels were measured on the day the participants completed a questionnaire regarding the presence of dry eye symptoms (persistent dryness or eye irritation). The population was divided into low and high groups by median level (4.26 and 2.89 µg/L for males and females, respectively). Results Self-reported dry eye symptoms were present in 13.0% of the cohort. Participants with dry eye symptoms were significantly more likely to have blood mercury levels exceeding the median than those without dry eye symptoms (45.7% vs 51.7%, p=0.021). Logistic regression analysis showed that, after adjusting for age, gender, education, total household income, smoking status, heavy alcohol use, sleep time, perceived stress status, total cholesterol levels and atopy history, dry eye symptoms were significantly associated with blood mercury levels that exceeded the median (reference: lower mercury group; OR, 1.324; 95% CI 1.059 to 1.655; p<0.05). Conclusions High blood mercury levels were associated with dry eye symptoms in a nationally representative Korean population. PMID:27121705

  10. Are higher blood mercury levels associated with dry eye symptoms in adult Koreans? A population-based cross-sectional study.

    PubMed

    Chung, So-Hyang; Myong, Jun-Pyo

    2016-04-27

    The purpose of this study was to investigate whether blood mercury concentrations associated with the presence of dry eye symptoms in a nationally representative Korean population. Population-based prospective cross-sectional study using the heavy metal data set of the 2010-2012 Korean National Health and Nutrition Examination Survey (KNHANES). A total of 4761 adult Koreans were the eligible population in this study. Of the 7162 survey participants, 2401 were excluded because they were <19 years of age, there were missing data in the heavy metal data set, or they had diabetes, rheumatoid arthritis, thyroid disease, asthma, depression and/or under-the-eye surgery. Blood mercury levels were measured on the day the participants completed a questionnaire regarding the presence of dry eye symptoms (persistent dryness or eye irritation). The population was divided into low and high groups by median level (4.26 and 2.89 µg/L for males and females, respectively). Self-reported dry eye symptoms were present in 13.0% of the cohort. Participants with dry eye symptoms were significantly more likely to have blood mercury levels exceeding the median than those without dry eye symptoms (45.7% vs 51.7%, p=0.021). Logistic regression analysis showed that, after adjusting for age, gender, education, total household income, smoking status, heavy alcohol use, sleep time, perceived stress status, total cholesterol levels and atopy history, dry eye symptoms were significantly associated with blood mercury levels that exceeded the median (reference: lower mercury group; OR, 1.324; 95% CI 1.059 to 1.655; p<0.05). High blood mercury levels were associated with dry eye symptoms in a nationally representative Korean population. 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/

  11. Corneal thickness in a population-based, cross-sectional study: the Tehran Eye Study.

    PubMed

    Hashemi, Hassan; Yazdani, Kamran; Mehravaran, Shiva; KhabazKhoob, Mehdi; Mohammad, Kazem; Parsafar, Hiva; Fotouhi, Akbar

    2009-05-01

    To determine the distribution of corneal thickness at 6 different points in an Iranian population and find any possible relationship between the thickness values and some independent variables. As part of the "Tehran Eye Study," 410 people (800 eyes) aged 14 years and older, residing in the first 4 municipality areas of Tehran, were selected through a stratified random cluster sampling method. The participants were examined with Orbscan II to measure the corneal thickness at the central, thinnest, and 4 peripheral points of the cornea. In addition, the relationships between central corneal thickness (CCT) values and variables of age, sex, refractive error, pupil diameter, corneal diameter, anterior chamber depth (ACD), and body mass index were assessed. The design effect was also considered, and all estimates were standardized for age and sex. The reported results pertain to the right eyes only. The mean thickness (+/-SD) at the central and thinnest points was 555.6 +/- 39.9 and 550.7 +/- 40.6 microm, respectively. The minimum corneal thickness was below 500 microm in 9.6% of the participants. The superior area showed the largest thickness, and the thinnest point was most commonly in the inferotemporal quadrant. The mean "distance" and "thickness difference" between the central and thinnest points were 0.52 +/- 0.31 mm and 4.85 +/- 6.2 microm, respectively, and they showed a significant direct relationship (r = 0.708 and P < 0.001). Neither sex had a significant relationship with thickness values at different areas. Participants younger than 20 years, compared with those older than 20, had significantly thicker corneas (P = 0.001 for the central and thinnest points, P < 0.001 for peripheral areas). In the multiple regression model, age and ACD showed significant inverse correlations with CCT. The mean CCT in the present study was 555.6 microm, which is relatively higher in comparison with that in other ethnic groups. In the multiple regression model, age and ACD

  12. Preventing Eye Injuries

    MedlinePlus

    ... Stories Español Eye Health / Eye Health A-Z Eye Injuries Sections Preventing Eye Injuries Recognizing and Treating ... Infographic Five Steps to Safer Champagne Celebrations Preventing Eye Injuries Reviewed by: Brenda Pagan-Duran MD Mar. ...

  13. About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro study.

    PubMed

    Galante, R; Paradiso, P; Moutinho, M G; Fernandes, A I; Mata, J L G; Matos, A P A; Colaço, R; Saramago, B; Serro, A P

    2015-01-01

    The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug-loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate-based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. pHEMA-UV revealed some superficial porosity and a lower short-range order than pHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered.

  14. Thyroid Eye Disease: Towards an Evidence Base for Treatment in the 21st Century

    PubMed Central

    Gillespie, Erin F.; Smith, Terry J.; Douglas, Raymond S.

    2012-01-01

    Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves’ disease. Incomplete understanding of its pathogenesis has hindered development of targeted therapies that might alter the natural course of disease. Smoking cessation and maintenance of euthyroidism appear to reduce the rate of onset and severity of TED. Recent evidence suggests that selenium may lessen the inflammatory symptoms in mild disease. Corticosteroids remain the primary treatment for patients with moderate to severe active TED. Surgical decompression is commonly undertaken in the chronic stable phase, and only rarely in the active phase when vision is threatened by compressive optic neuropathy. Orbital radiotherapy remains an adjunctive strategy during active disease. Targeted immunotherapies have the potential to alter disease progression, but further evidence is needed to establish safety and efficacy. In this article, we review evidence from prospective therapeutic trials of several treatment modalities. We focus on moderate to severe active TED. PMID:22354545

  15. Thyroid eye disease: towards an evidence base for treatment in the 21st century.

    PubMed

    Gillespie, Erin F; Smith, Terry J; Douglas, Raymond S

    2012-06-01

    Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves' disease. Incomplete understanding of its pathogenesis has hindered development of targeted therapies that might alter the natural course of disease. Smoking cessation and maintenance of euthyroidism appear to reduce the rate of onset and severity of TED. Recent evidence suggests that selenium may lessen the inflammatory symptoms in mild disease. Corticosteroids remain the primary treatment for patients with moderate to severe active TED. Surgical decompression is commonly undertaken in the chronic stable phase, and only rarely in the active phase when vision is threatened by compressive optic neuropathy. Orbital radiotherapy remains an adjunctive strategy during active disease. Targeted immunotherapies have the potential to alter disease progression, but further evidence is needed to establish safety and efficacy. In this article, we review evidence from prospective therapeutic trials of several treatment modalities. We focus on moderate to severe active TED.

  16. Screening neonatal jaundice based on the sclera color of the eye using digital photography.

    PubMed

    Leung, Terence S; Kapur, Karan; Guilliam, Ashley; Okell, Jade; Lim, Bee; MacDonald, Lindsay W; Meek, Judith

    2015-11-01

    A new screening technique for neonatal jaundice is proposed exploiting the yellow discoloration in the sclera. It involves taking digital photographs of newborn infants' eyes (n = 110) and processing the pixel colour values of the sclera to predict the total serum bilirubin (TSB) levels. This technique has linear and rank correlation coefficients of 0.75 and 0.72 (both p<0.01) with the measured TSB. The mean difference ( ± SD) is 0.00 ± 41.60 µmol/l. The receiver operating characteristic curve shows that this technique can identify subjects with TSB above 205 µmol/l with sensitivity of 1.00 and specificity of 0.50, showing its potential as a screening device.

  17. Screening neonatal jaundice based on the sclera color of the eye using digital photography

    PubMed Central

    Leung, Terence S.; Kapur, Karan; Guilliam, Ashley; Okell, Jade; Lim, Bee; MacDonald, Lindsay W.; Meek, Judith

    2015-01-01

    A new screening technique for neonatal jaundice is proposed exploiting the yellow discoloration in the sclera. It involves taking digital photographs of newborn infants’ eyes (n = 110) and processing the pixel colour values of the sclera to predict the total serum bilirubin (TSB) levels. This technique has linear and rank correlation coefficients of 0.75 and 0.72 (both p<0.01) with the measured TSB. The mean difference ( ± SD) is 0.00 ± 41.60 µmol/l. The receiver operating characteristic curve shows that this technique can identify subjects with TSB above 205 µmol/l with sensitivity of 1.00 and specificity of 0.50, showing its potential as a screening device. PMID:26601015

  18. Multimodal eye recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

    2010-04-01

    Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

  19. Magnetic eye tracking in mice

    PubMed Central

    Payne, Hannah L

    2017-01-01

    Eye movements provide insights about a wide range of brain functions, from sensorimotor integration to cognition; hence, the measurement of eye movements is an important tool in neuroscience research. We describe a method, based on magnetic sensing, for measuring eye movements in head-fixed and freely moving mice. A small magnet was surgically implanted on the eye, and changes in the magnet angle as the eye rotated were detected by a magnetic field sensor. Systematic testing demonstrated high resolution measurements of eye position of <0.1°. Magnetic eye tracking offers several advantages over the well-established eye coil and video-oculography methods. Most notably, it provides the first method for reliable, high-resolution measurement of eye movements in freely moving mice, revealing increased eye movements and altered binocular coordination compared to head-fixed mice. Overall, magnetic eye tracking provides a lightweight, inexpensive, easily implemented, and high-resolution method suitable for a wide range of applications. PMID:28872455

  20. Eye Symptom Questionnaire to Evaluate Anterior Eye Health.

    PubMed

    Woodward, Maria A; Valikodath, Nita G; Newman-Casey, Paula Anne; Niziol, Leslie M; Musch, David C; Lee, Paul P

    2017-06-14

    Ophthalmologists assess eye complaints with a careful history and eye examination; however, other types of physicians have limited tools to evaluate anterior segment (AS) eye diseases. We identified the eye symptom questions that providers should ask to help determine the presence and urgency of AS eye diseases. Persons with and without AS disease completed a self-report eye symptom questionnaire (ESQ) based on the National Institutes of Health Toolbox symptom items in an academic center's corneal and comprehensive eye clinics. Gold standard ophthalmic examination determined the presence and urgency of AS disease. The association between reported symptom severity and the probability of AS disease, or urgent AS disease, was evaluated using logistic regression models, and sensitivity and specificity of the ESQ were also calculated. A total of 324 eyes of 162 subjects were included in the study. Of these, AS disease was present in 255 eyes (79%); of which, 111 eyes showed urgent disease. Increasing symptom severity for eye pain (odds ratio [OR]=2.58; P<0.001), glare (OR=2.61; P=0.001), and blurry vision (OR=1.98; P<0.001) were associated with increased odds of AS disease. Increasing symptom severity for eye pain (OR=2.02; P<0.001), eye redness (OR=1.69; P=0.02), and blurry vision (OR=1.41, P=0.01) were associated with increased odds of urgent AS disease. For the primary analysis with mild symptoms considered relevant, the sensitivity of the ESQ to detect AS disease was 83% and to detect urgent AS disease was 92%. Symptoms of eye pain, glare, redness, and blurry vision indicate the presence and urgency of AS disease.

  1. Statistical eye model for normal eyes.

    PubMed

    Rozema, Jos J; Atchison, David A; Tassignon, Marie-José

    2011-06-23

    To create a binocular statistical eye model based on previously measured ocular biometric data. Thirty-nine parameters were determined for a group of 127 healthy subjects (37 male, 90 female; 96.8% Caucasian) with an average age of 39.9 ± 12.2 years and spherical equivalent refraction of -0.98 ± 1.77 D. These parameters described the biometry of both eyes and the subjects' age. Missing parameters were complemented by data from a previously published study. After confirmation of the Gaussian shape of their distributions, these parameters were used to calculate their mean and covariance matrices. These matrices were then used to calculate a multivariate Gaussian distribution. From this, an amount of random biometric data could be generated, which were then randomly selected to create a realistic population of random eyes. All parameters had Gaussian distributions, with the exception of the parameters that describe total refraction (i.e., three parameters per eye). After these non-Gaussian parameters were omitted from the model, the generated data were found to be statistically indistinguishable from the original data for the remaining 33 parameters (TOST [two one-sided t tests]; P < 0.01). Parameters derived from the generated data were also significantly indistinguishable from those calculated with the original data (P > 0.05). The only exception to this was the lens refractive index, for which the generated data had a significantly larger SD. A statistical eye model can describe the biometric variations found in a population and is a useful addition to the classic eye models.

  2. The Q368STOP myocilin mutation in a population-based cohort: the Blue Mountains Eye Study.

    PubMed

    Baird, Paul N; Richardson, Andrea J; Craig, Jamie E; Rochtchina, Elena; Mackey, David A; Mitchell, Paul

    2005-06-01

    To investigate the prevalence of the Q368STOP myocilin mutation in a population-based cohort: the Blue Mountains Eye Study (BMES). Population-based study. DNA was extracted from 2,142 individuals collected through the BMES, including 31 individuals with glaucoma. All individuals were screened for the presence of the Q368STOP mutation of myocilin. Genotyping of the microsatellite markers My5, My3, D1S2815, and D1S1619 was also undertaken. None of the 31 open-angle glaucoma-positive individuals presented with the Q368STOP mutation. However, two individuals (aged 56 and 72) with no clinical signs of OAG, were identified with this mutation. Allele sharing at the four microsatellite markers defining the Q368STOP disease haplotype for OAG was found in these two individuals. The Q368STOP myocilin mutation occurs at a low prevalence (0.09%) in a general, older population.

  3. [Population-based study of tear production in healthy individuals and patients with dry eye syndrome in Altai Republic].

    PubMed

    Onishchenko, A L; Kolbasko, A V; Shirina, M A

    2012-01-01

    For the first time population-based study of tear production was performed, prevalence and risk factors of dry eye syndrome (DES) were determined in native ethnic group of Altai Republic--tubalars. Authors examined 673 people, representing 44% of the whole tubalar population. The mean total tear production (Shirmer test I) was 13,3 +/- 0,3 mm in healthy (without DES signs) tubalars. It ranges in 22,6% of healthy tubalars from 0 to 5 mm, in 20,8%--6 to 11 mm, in 20,5%--12 to 17 mm, in 34,5%-- > 17 mm. Prevalence of DES in tubalar population is 86,18 per thousand. Total tear production (Shirmer test I) in tubalars with DES ranges from 0 to 5 mm in 34%, 6-11 mm in 31,5%, 12-17 mm in 21% and > 17 mm in 13% of eyes. This results showed Shirmer test I to be nonspecific in diagnosis of DES. In author's opinion this test may be useful for follow-up and for assessment of treatment efficacy.

  4. Acupuncture therapy is more effective than artificial tears for dry eye syndrome: evidence based on a meta-analysis.

    PubMed

    Yang, Lei; Yang, Zongguo; Yu, Hong; Song, Hui

    2015-01-01

    Background. The efficacy of acupuncture in dry eye syndrome patients remains controversial. Methods. Pubmed, Ovid, Cochrane libraries, CNKI, Wanfang, and CQVIP databases were electronically searched until October 1, 2014. Outcomes including tear break-up time (BUT), Schirmer I test (SIT), and cornea fluorescein staining (CFS) were analyzed. A meta-analysis was performed using both fixed- and random-effects models based on heterogeneity across studies. Results. Seven studies were included in this study; 198 and 185 patients were randomly treated with acupuncture and artificial tears, respectively. The overall BUT of patients in acupuncture group was significantly longer than that of the artificial tears group after treatment (P < 0.00001). The SIT was significantly higher in the acupuncture group than that in the artificial tears group after treatment (P = 0.001). The CFS of patients in acupuncture group was significantly improved compared to that in artificial group (P < 0.0001). Conclusions. Acupuncture therapy is effective for the dry eye patients, partly better than artificial tear treatment.

  5. The Wills Eye Glaucoma App: Interest of Patients and Their Caregivers in a Smartphone-based and Tablet-based Glaucoma Application.

    PubMed

    Waisbourd, Michael; Dhami, Hermandeep; Zhou, Chen; Hsieh, Michael; Abichandani, Pramod; Pro, Michael J; Moster, Marlene R; Katz, L Jay; Hark, Lisa A; Myers, Jonathan S

    2016-09-01

    To evaluate the interest of glaucoma patients and their caregivers in a smartphone-based and tablet-based glaucoma application (App), developed by the Wills Eye Glaucoma Research Center in collaboration with Drexel University. Cross-sectional survey of patients with glaucoma and their caregivers. Main outcome measures are answers to survey questions regarding how receptive participants are to using the Glaucoma App. Fifty subjects completed the survey. The mean age (SD) was 59.5 (±17.3) years. A total of 88.6% of the participants lived in a household with access to a smartphone or tablet. The majority (72.3%) of participants would consider downloading the Glaucoma App, and younger participants (<65 y) were more likely to do so compared with their older (≥65 y) counterparts, P=0.025. Participants were more likely to download the App if it was free of charge, compared with a version that costs $3, P=0.018. Although only about one third (37.8%) of participants used eye drop reminders, nearly 3 of 4 (72.9%) participants were receptive to using the automated reminder feature of the Glaucoma App. Glaucoma patients and their caregivers were very interested in using a Glaucoma App; however, many were not willing to spend $3 for an App they seem to value. The free Wills Eye Glaucoma App currently available on the Apple store, includes educational videos, eye drop and appointment reminders, medical and ocular data storage, visual field tutorial, and intraocular pressure tracker. These features aim to increase patients' level of knowledge about glaucoma and improve their adherence to medication and follow-up appointment recommendations.

  6. The development of competency-based education for mid-level eye care professionals: a process to foster an appropriate, widely accepted and socially accountable initiative.

    PubMed

    du Toit, R; Palagyi, A; Brian, G

    2010-08-01

    The Western Pacific region has a dearth of appropriately educated eye care providers, training programs and large and increasing eye health needs. To ensure regional eye health needs would be met, an iterative process sought triangulations between the literature and consultations with local stakeholders from various fields. This information was used to develop competencies to meet quality standards for educational outcomes. A framework for social accountability was used to evaluate the proposed educational initiative, and the subsequent eye care service the graduates could provide. Current human resource development and deployment is inadequate to protect and restore ocular and visual health in the region. Some of these service needs could be met by task-shifting from conventional health professionals to appropriately trained mid-level personnel. A competency-based curriculum was developed to meet eye care needs and define this new cadre of mid-level professionals in relation to other professionals. This initiative met the relevance, equity, cost effectiveness and quality criteria for social accountability. The consultative process resulted in broad acceptance of the need for an appropriately educated mid-level cadre that could be recruited, educated, deployed, supported and retained in the Western Pacific region to supplement and substitute for established eye care professionals. This process also provided validation of the initiative prior to implementation, as being appropriate to the region, meeting educational standards and social accountability criteria for outcomes. It could be replicated in other regions that wish to develop such an education for new cadres of health care professionals.

  7. Eye-Directed Overpressure Airwave-Induced Trauma Causes Lasting Damage to the Anterior and Posterior Globe: A Model for Testing Cell-Based Therapies

    PubMed Central

    Bricker-Anthony, Courtney; Hines-Beard, Jessica

    2016-01-01

    Abstract Purpose: Characterization of the response of the Balb/c mouse to an eye-directed overpressure airwave, with the hypothesis that this mouse strain and model is useful for testing potential therapeutics for the treatment of traumatic eye injury. Methods: The left eyes of adult Balb/c mice were exposed to an eye-directed overpressure airwave. Intraocular pressure (IOP) was measured and eyes were inspected for gross pathology changes. Optical coherence tomography and histology were used to examine the structural integrity of the retina and optic nerve. Immunohistochemistry, in vivo molecular fluorophores, and a multiplex enzyme-linked immunosorbent assay were utilized to identify changes in cell death, neuroinflammation, and oxidative stress. Results: This model induced a transient increase in IOP, corneal injuries, infrequent large retinal detachments, retinal pigment epithelium (RPE) vacuolization, glial reactivity, and retinal cell death. Both the corneal damage and RPE vacuolization persisted with time. Optic nerve degeneration occurred as early as 7 days postinjury and persisted out to 60 days. Retinal cell death, increased levels of reactive oxygen species, and neuroinflammation were detected at 7 days postinjury. Conclusions: The injury profile of the Balb/c mouse is consistent with commonly observed pathologies in blast-exposed patients. The damage is throughout the eye and persistent, making this mouse model useful for testing cell-based therapies. PMID:26982447

  8. Eye-Directed Overpressure Airwave-Induced Trauma Causes Lasting Damage to the Anterior and Posterior Globe: A Model for Testing Cell-Based Therapies.

    PubMed

    Bricker-Anthony, Courtney; Hines-Beard, Jessica; Rex, Tonia S

    2016-06-01

    Characterization of the response of the Balb/c mouse to an eye-directed overpressure airwave, with the hypothesis that this mouse strain and model is useful for testing potential therapeutics for the treatment of traumatic eye injury. The left eyes of adult Balb/c mice were exposed to an eye-directed overpressure airwave. Intraocular pressure (IOP) was measured and eyes were inspected for gross pathology changes. Optical coherence tomography and histology were used to examine the structural integrity of the retina and optic nerve. Immunohistochemistry, in vivo molecular fluorophores, and a multiplex enzyme-linked immunosorbent assay were utilized to identify changes in cell death, neuroinflammation, and oxidative stress. This model induced a transient increase in IOP, corneal injuries, infrequent large retinal detachments, retinal pigment epithelium (RPE) vacuolization, glial reactivity, and retinal cell death. Both the corneal damage and RPE vacuolization persisted with time. Optic nerve degeneration occurred as early as 7 days postinjury and persisted out to 60 days. Retinal cell death, increased levels of reactive oxygen species, and neuroinflammation were detected at 7 days postinjury. The injury profile of the Balb/c mouse is consistent with commonly observed pathologies in blast-exposed patients. The damage is throughout the eye and persistent, making this mouse model useful for testing cell-based therapies.

  9. Evaluation of the clinical efficacy and safety of an eye counter pad containing caffeine and vitamin K in emulsified Emu oil base

    PubMed Central

    Ahmadraji, Fatemeh; Shatalebi, Mohammad Ali

    2015-01-01

    Background: People strive to maintain the best look and have a youthful appearance. The skin around the eye is an area without many oil glands and collagen in comparison to the body rest, so it is more prone to fine lines and dehydration, which makes it look dull. The aim of this research is to develop and evaluate in vivo efficacy of an anti-wrinkle and dark circle eye pad consisting of 3% w/w caffeine and 1% vitamin K in a convenient, healthy, and cosmeceutical base. Materials and Methods: Pre-emulsions containing selected ingredients in a specified effective concentration were prepared. The selected formulation, based upon pharmaceutical parameters, was coated on a nonwoven fabric in an eye counter shape, and stored in a jar. Then in vivo trial was carried out for investigation of its anti-wrinkling efficacy on 11 healthy women. In a single blind trial, the sample pad was applied under the right eye and the placebo pad, consisting of water, was placed under the left eye simultaneously. The efficacy and safety of the formulation was evaluated visually and with a multi skin test MC 900 instrument. Result: After four weeks, the skin around the right eye of all the subjects experienced a reduction in the depth of wrinkles and dark circles, and from a subjective point of view, the appearance and elasticity of the skin were improved. Conclusions: The caffeine pad containing vitamin K in an Emu oil base shows an improvement in eye counter appearance with anti-dark circle capacity and as an emollient. PMID:25625116

  10. Clinical evaluation of a dose monitoring software tool based on Monte Carlo Simulation in assessment of eye lens doses for cranial CT scans.

    PubMed

    Guberina, Nika; Suntharalingam, Saravanabavaan; Naßenstein, Kai; Forsting, Michael; Theysohn, Jens; Wetter, Axel; Ringelstein, Adrian

    2016-10-01

    The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner. Eye lens doses calculated by the dose monitoring tool based on MCS and assessed with TLDs were compared. Eye lens doses are summarized as follows: (I) CT angiography (a) MCS 7 mSv, (b) TLD 5 mSv; (II) unenhanced, cranial CT scan with gantry angulation, (c) MCS 45 mSv, (d) TLD 5 mSv; (III) unenhanced, cranial CT scan without gantry angulation (e) MCS 38 mSv, (f) TLD 35 mSv. Intermodality comparison shows an inaccurate calculation of eye lens doses in unenhanced cranial CT protocols at the single source CT scanner due to the disregard of gantry angulation. On the contrary, the dose monitoring tool showed an accurate calculation of eye lens doses at the dual source CT scanner without gantry angulation and for CT angiography examinations. The dose monitoring software tool based on MCS gave accurate estimates of eye lens doses in cranial CT protocols. However, knowledge of protocol and software specific influences is crucial for correct assessment of eye lens doses in routine clinical use.

  11. An Eye-Blinking-Based Beamforming Control Protocol for Hearing Aid Users With Neurological Motor Disease or Limb Amputation.

    PubMed

    Yoon, Jungmin; Nam, Kyoung Won; Lee, Jun Chang; Jang, Dong Pyo; Kim, In Young

    2017-02-01

    For hearing-impaired individuals with neurological motor deficits or finger/arm amputation due to accident or disease, hearing aid adjustment using a conventional finger manipulation-based remote controller is unavailable, and a more dedicated, hands-free alternative is required. In this study, we propose an eye-blinking-based beamforming control scheme for hearing aid users. Three electroencephalogram signals measured around the ears were utilized to detect eye-blinking patterns based on a three-layer artificial neural network. The performance of the proposed control scheme was evaluated by both subjective experiments and objective index comparison tests in simulated situations. Experimental results from the subjective test demonstrated that without the pretraining phase, the accuracy and latency time were 68.57 ± 18.50% and 10.06 ± 0.94 s, respectively; in contrast, after the pretraining phase, both the accuracy and latency time were improved to 91.00 ± 4.69% and 8.60 ± 1.05 s, respectively. In index comparison tests, the proposed control scheme exhibited improvements in the signal-to-noise ratio (SNR) as well as the segmental SNR in all tested situations, as compared to a conventional forward-focusing beamforming algorithm. We believe that the proposed control scheme provides a novel, hands-free way in which to control the operation of hearing aids for hearing-impaired patients with additional motor deficits or amputation. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  12. A naked eye aggregation assay for Pb2+ detection based on glutathione-coated gold nanostars

    NASA Astrophysics Data System (ADS)

    D'Agostino, Agnese; Taglietti, Angelo; Bassi, Barbara; Donà, Alice; Pallavicini, Piersandro

    2014-10-01

    Gold nanostars (AuNS) with a mean hydrodynamic size of 40 nm, obtained with a seed-growth approach using a zwitterionic surfactant (laurylsulfobetaine, LSB), were successfully coated with glutathione (GSH), obtaining a stable and purified solid product which can be easily stored and re-dissolved on need in 0.1 M aqueous solution of Hepes buffered at pH 7. Upon exposure to micromolar concentrations of Pb2+ cation, the GSH-coated nano-objects undergo a fast aggregation followed by sedimentation leading to complete precipitation in about an hour. The subsequent disappearing of the intense LSPR extinction can of course be followed spectrophotometrically but, most importantly, can be easily detected with the naked eye. No signs of this event are noticed when other divalent cations are added to the colloidal suspension in the same condition. A careful investigation was performed to study this selectivity and the behaviour of aggregation as a function of time and Pb2+ cation concentration. We demonstrate that an easy, rapid, instrument-free, visual detection of micromolar levels of Pb2+ is thus possible with this assay, showing a good selectivity towards other investigated metal cations.

  13. Synthesis and characterization of azo-guanidine based alcoholic media naked eye DNA sensor

    PubMed Central

    Hashmat, Uzma; Yousaf, Muhammad; Lal, Bhajan; Ullah, Shafiq; Holder, Alvin A.; Badshah, Amin

    2016-01-01

    DNA sensing always has an open meadow of curiosity for biotechnologists and other researchers. Recently, in this field, we have introduced an emerging class of molecules containing azo and guanidine functionalities. In this study, we have synthesized three new compounds (UA1, UA6 and UA7) for potential application in DNA sensing in alcoholic medium. The synthesized materials were characterized by elemental analysis, FTIR, UV-visible, 1H NMR and 13C NMR spectroscopies. Their DNA sensing potential were investigated by UV-visible spectroscopy. The insight of interaction with DNA was further investigated by electrochemical (cyclic voltammetry) and hydrodynamic (viscosity) studies. The results showed that compounds have moderate DNA binding properties, with the binding constants range being 7.2 × 103, 2.4 × 103 and 0.2 × 103 M−1, for UA1, UA6 and UA7, respectively. Upon binding with DNA, there was a change in colour (a blue shift in the λmax value) which was observable with a naked eye. These results indicated the potential of synthesized compounds as DNA sensors with detection limit 1.8, 5.8 and 4.0 ng µl−1 for UA1, UA6 and UA7, respectively. PMID:28018613

  14. On biometrics with eye movements.

    PubMed

    Zhang, Youming; Juhola, Martti

    2016-04-07

    Eye movements are a relatively novel data source for biometric identification. When video cameras applied to eye tracking become smaller and more efficient, this data source could offer interesting opportunities for the development of eye movement biometrics. In the present article, we study primarily biometric identification as seen as a classification task of multiple classes, and secondarily biometric verification considered as binary classification. Our research is based on the saccadic eye movement signal measurements from 109 young subjects. In order to test the data measured, we use a procedure of biometric identification according to the one-versus-one (subject) principle. In a development from our previous research, which also involved biometric verification based on saccadic eye movements, we now apply another eye movement tracker device with a higher sampling frequency of 250 Hz. The results obtained are good, with correct identification rates at 80-90% at their best.

  15. SMARTPHONE-BASED DILATED FUNDUS PHOTOGRAPHY AND NEAR VISUAL ACUITY TESTING AS INEXPENSIVE SCREENING TOOLS TO DETECT REFERRAL WARRANTED DIABETIC EYE DISEASE.

    PubMed

    Toy, Brian C; Myung, David J; He, Lingmin; Pan, Carolyn K; Chang, Robert T; Polkinhorne, Alison; Merrell, Douglas; Foster, Doug; Blumenkranz, Mark S

    2016-05-01

    To compare clinical assessment of diabetic eye disease by standard dilated examination with data gathered using a smartphone-based store-and-forward teleophthalmology platform. 100 eyes of 50 adult patients with diabetes from a health care safety-net ophthalmology clinic. All patients underwent comprehensive ophthalmic examination. Concurrently, a smartphone was used to estimate near visual acuity and capture anterior and dilated posterior segment photographs, which underwent masked, standardized review. Quantitative comparison of clinic and smartphone-based data using descriptive, kappa, Bland-Altman, and receiver operating characteristic analyses was performed. Smartphone visual acuity was successfully measured in all eyes. Anterior and posterior segment photography was of sufficient quality to grade in 96 and 98 eyes, respectively. There was good correlation between clinical Snellen and smartphone visual acuity measurements (rho = 0.91). Smartphone-acquired fundus photographs demonstrated 91% sensitivity and 99% specificity to detect moderate nonproliferative and worse diabetic retinopathy, with good agreement between clinic and photograph grades (kappa = 0.91 ± 0.1, P < 0.001; AUROC = 0.97, 95% confidence interval, 0.93-1). The authors report a smartphone-based telemedicine system that demonstrated sensitivity and specificity to detect referral-warranted diabetic eye disease as a proof-of-concept. Additional studies are warranted to evaluate this approach to expanding screening for diabetic retinopathy.

  16. Development towards Compact Nitrocellulose-Based Interferometric Biochips for Dry Eye MMP9 Label-Free In-Situ Diagnosis.

    PubMed

    Santamaría, Beatriz; Laguna, María F; López-Romero, David; Hernandez, Ana L; Sanza, Francisco J; Lavín, Álvaro; Casquel, Rafael; Maigler, María V; Espinosa, Rocío L; Holgado, Miguel

    2017-05-19

    A novel compact optical biochip based on a thin layer-sensing surface of nitrocellulose is used for in-situ label-free detection of metalloproteinase (MMP9) related to dry eye disease. In this article, a new integrated chip with different interferometric transducers layout with an optimal sensing surface is reported for the first time. We demonstrate that specific antibodies can be immobilized onto these transducers with a very low volume of sample and with good orientation. Many sensing transducers constitute the presented biochip in order to yield statistical data and stability in the acquired measurements. As a result, we report the recognition curve for pure recombinant MMP9, tests of model tears with MMP9, and real tear performance from patients, with a promising limit of detection.

  17. Development towards Compact Nitrocellulose-Based Interferometric Biochips for Dry Eye MMP9 Label-Free In-Situ Diagnosis

    PubMed Central

    Santamaría, Beatriz; Laguna, María F.; López-Romero, David; Hernandez, Ana L.; Sanza, Francisco J.; Lavín, Álvaro; Casquel, Rafael; Maigler, María V.; Espinosa, Rocío L.; Holgado, Miguel

    2017-01-01

    A novel compact optical biochip based on a thin layer-sensing surface of nitrocellulose is used for in-situ label-free detection of metalloproteinase (MMP9) related to dry eye disease. In this article, a new integrated chip with different interferometric transducers layout with an optimal sensing surface is reported for the first time. We demonstrate that specific antibodies can be immobilized onto these transducers with a very low volume of sample and with good orientation. Many sensing transducers constitute the presented biochip in order to yield statistical data and stability in the acquired measurements. As a result, we report the recognition curve for pure recombinant MMP9, tests of model tears with MMP9, and real tear performance from patients, with a promising limit of detection. PMID:28534808

  18. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  19. Eye Twitching

    MedlinePlus

    ... aspects of life. Hemifacial spasm involves twitches of muscles on one side of the face, including the eyelid. Eye twitching usually goes away on its own within a few days or weeks with rest, stress relief and decreased caffeine. Schedule an appointment with your doctor if: The ...

  20. Googly Eyes

    ERIC Educational Resources Information Center

    Boss, Susan

    2009-01-01

    Beverage take-out trays are funky in their form and function. In this article, the author describes how to make googly eye masks out of discarded take-out trays and other common recycled or discarded materials. (Contains 1 online resource.)

  1. Increased Burden of Vision Impairment and Eye Diseases in Persons with Chronic Kidney Disease — A Population-Based Study

    PubMed Central

    Wong, Chee Wai; Lamoureux, Ecosse L.; Cheng, Ching-Yu; Cheung, Gemmy Chui Ming; Tai, E. Shyong; Wong, Tien Y.; Sabanayagam, Charumathi

    2016-01-01

    Background Chronic kidney disease (CKD) has been shown to be associated with diabetic retinopathy (DR) and age-related macular degeneration (AMD), leading causes of blindness in elderly adults in previous studies. However, the association of CKD with visual impairment (VI) is not clear. We aimed to examine the association of CKD with VI and other age-related ocular diseases in a population-based sample of Asian adults. Methods We analyzed data from 10,033 adults aged 40–80 years who participated in the Singapore Epidemiology of Eye Diseases (SEED, 2004–11) Study. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 from serum creatinine. VI was defined as best-corrected visual acuity < 20/40 in the better eye. Cataract, retinopathy, DR, glaucoma and AMD were assessed using standardized ocular examination, retinal photography and visual field assessments. The associations of CKD with VI and ocular conditions were examined using logistic regression models adjusted for age, sex, race, smoking, alcohol intake, education status, body mass index, systolic blood pressure, diabetes mellitus, cholesterol levels and cardiovascular disease. Findings The prevalence of VI and ocular disease were significantly higher in participants with CKD (36.1% and 84.7%) than in those without (12.9% and 54.3%, both p < 0.001). In multivariable models, CKD was significantly associated with VI (odds ratio [95% confidence interval] = 1.34 [1.14–1.58]), any ocular disease (1.28 [1.03–1.61]), cataract (1.24 [1.01–1.52]), any retinopathy (1.77 [1.45–2.15]), and DR (1.94 [1.47–2.54]). Interpretation The burden of VI and eye diseases is high among persons with CKD. Our findings suggest that it may be useful to screen for ocular disease and VI in persons with CKD. PMID:27077127

  2. TH-E-17A-10: Markerless Lung Tumor Tracking Based On Beams Eye View EPID Images

    SciTech Connect

    Chiu, T; Kearney, V; Liu, H; Jiang, L; Foster, R; Mao, W; Rozario, T; Bereg, S; Klash, S

    2014-06-15

    Purpose: Dynamic tumor tracking or motion compensation techniques have proposed to modify beam delivery following lung tumor motion on the flight. Conventional treatment plan QA could be performed in advance since every delivery may be different. Markerless lung tumor tracking using beams eye view EPID images provides a best treatment evaluation mechanism. The purpose of this study is to improve the accuracy of the online markerless lung tumor motion tracking method. Methods: The lung tumor could be located on every frame of MV images during radiation therapy treatment by comparing with corresponding digitally reconstructed radiograph (DRR). A kV-MV CT corresponding curve is applied on planning kV CT to generate MV CT images for patients in order to enhance the similarity between DRRs and MV treatment images. This kV-MV CT corresponding curve was obtained by scanning a same CT electron density phantom by a kV CT scanner and MV scanner (Tomotherapy) or MV CBCT. Two sets of MV DRRs were then generated for tumor and anatomy without tumor as the references to tracking the tumor on beams eye view EPID images. Results: Phantom studies were performed on a Varian TrueBeam linac. MV treatment images were acquired continuously during each treatment beam delivery at 12 gantry angles by iTools. Markerless tumor tracking was applied with DRRs generated from simulated MVCT. Tumors were tracked on every frame of images and compared with expected positions based on programed phantom motion. It was found that the average tracking error were 2.3 mm. Conclusion: This algorithm is capable of detecting lung tumors at complicated environment without implanting markers. It should be noted that the CT data has a slice thickness of 3 mm. This shows the statistical accuracy is better than the spatial accuracy. This project has been supported by a Varian Research Grant.

  3. Naked-eye sensitive ELISA-like assay based on gold-enhanced peroxidase-like immunogold activity.

    PubMed

    Wang, Shasha; Chen, Zhaopeng; Choo, Jaebum; Chen, Lingxin

    2016-02-01

    A naked-eye sensitive ELISA-like assay was developed based on gold-enhanced peroxidase-like activity of gold nanoparticles (AuNPs). Using human IgG (H-IgG) as an analytical model, goat anti-human IgG antibody (anti-IgG) adsorbed on microtiter plate and AuNPs-labeled anti-IgG acted as capture antibody and detection antibody, respectively. Because the surfaces of AuNPs were blocked by protein molecules, the peroxidase-like activity of AuNPs was almost inhibited, evaluated by the catalytic oxidation of peroxidase enzyme substrate 3,3',5,5'-tetramethylbenzidine (TMB), which could produce a bright blue color in the presence of H2O2. Fortunately, the catalytic ability of AuNPs was dramatically increased by the deposition of gold due to the formation of a new gold shell on immunogold. Under optimal reaction conditions, the colorimetric immunoassay presented a good linear relationship in the range of 0.7-100 ng/mL and the limit of detection (LOD) of 0.3 ng/mL calculated by 3σ/S for UV-vis detection, and obtained LOD of 5 ng/mL for naked-eye detection. The obtained results were competitive with conventional sandwich ELISA with the LOD of 1.6 ng/mL. Furthermore, this developed colorimetric immunoassay was successfully applied to diluted human serum and fetal bovine serum samples, and predicted a broad prospect for the use of peroxidase-like activity involving nanomaterials in bioassay and diagnostics.

  4. Building metamemorial knowledge over time: insights from eye tracking about the bases of feeling-of-knowing and confidence judgments

    PubMed Central

    Chua, Elizabeth F.; Solinger, Lisa A.

    2015-01-01

    Metamemory processes depend on different factors across the learning and memory time-scale. In the laboratory, subjects are often asked to make prospective feeling-of-knowing (FOK) judgments about target retrievability, or are asked to make retrospective confidence judgments (RCJs) about the retrieved target. We examined distinct and shared contributors to metamemory judgments, and how they were built over time. Eye movements were monitored during a face-scene associative memory task. At test, participants viewed a studied scene, then rated their FOK that they would remember the associated face. This was followed by a forced choice recognition test and RCJs. FOK judgments were less accurate than RCJ judgments, showing that the addition of mnemonic experience can increase metacognitive accuracy over time. However, there was also evidence that the given FOK rating influenced RCJs. Turning to eye movements, initial analyses showed that higher cue fluency was related to both higher FOKs and higher RCJs. However, further analyses revealed that the effects of the scene cue on RCJs were mediated by FOKs. Turning to the target, increased viewing time and faster viewing of the correct associate related to higher FOKs, consistent with the idea that target accessibility is a basis of FOKs. In contrast, the amount of viewing directed to the chosen face, regardless of whether it was correct, predicted higher RCJs, suggesting that choice experience is a significant contributor RCJs. We also examined covariates of the change in RCJ rating from the FOK rating, and showed that increased and faster viewing of the chosen face predicted raising one’s confidence above one’s FOK. Taken together these results suggest that metamemory judgments should not be thought of only as distinct subjective experiences, but complex processes that interact and evolve as new psychological bases for subjective experience become available. PMID:26347677

  5. Eye Complications in IBD

    MedlinePlus

    ... Home > Resources > Eye Complications in IBD Go Back Eye Complications in IBD Email Print + Share Approximately 10% ... doctor’s attention sooner rather than later. TYPES OF EYE DISORDERS UVEITIS One of the most common eye ...

  6. Eye Injuries at Work

    MedlinePlus

    ... Ophthalmologist Patient Stories Español Eye Health / Tips & Prevention Eye Injuries Sections Preventing Eye Injuries Recognizing and Treating ... Numbers — Infographic Five Steps to Safer Champagne Celebrations Eye Injuries at Work Edited by: Shirley Dang Feb. ...

  7. Conjunctivitis (Pink Eye)

    MedlinePlus

    ... can be embedded on web pages. Conjunctivitis (Pink Eye) One-Page Overview Pink, itchy eyes? Conjunctivitis – or ... yourself from getting and spreading pink eye . Pink Eye: What To Do Discusses causes and treatment, when ...

  8. Eye Injuries at Home

    MedlinePlus

    ... Ophthalmologist Patient Stories Español Eye Health / Tips & Prevention Eye Injuries Sections Preventing Eye Injuries Recognizing and Treating ... Numbers — Infographic Five Steps to Safer Champagne Celebrations Eye Injuries at Home Reviewed by: Brenda Pagan-Duran ...

  9. Eye muscle repair - discharge

    MedlinePlus

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  10. Why Do Eyes Water?

    MedlinePlus

    ... Happens in the Operating Room? Why Do Eyes Water? KidsHealth > For Kids > Why Do Eyes Water? A ... out of your nose. continue Why Do Eyes Water? Eyes water for lots of different reasons besides ...

  11. Why Do Eyes Water?

    MedlinePlus

    ... Lifesaver Kids Talk About: Coaches Why Do Eyes Water? KidsHealth > For Kids > Why Do Eyes Water? Print ... out of your nose. continue Why Do Eyes Water? Eyes water for lots of different reasons besides ...

  12. Eye Movement Disorders

    MedlinePlus

    ... t work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder ... of the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over ...

  13. Video-Based Eye Tracking to Detect the Attention Shift: A Computer Classroom Context-Aware System

    ERIC Educational Resources Information Center

    Kuo, Yung-Lung; Lee, Jiann-Shu; Hsieh, Min-Chai

    2014-01-01

    Eye and head movements evoked in response to obvious visual attention shifts. However, there has been little progress on the causes of absent-mindedness so far. The paper proposes an attention awareness system that captures the conditions regarding the interaction of eye gaze and head pose under various attentional switching in computer classroom.…

  14. Video-Based Eye Tracking to Detect the Attention Shift: A Computer Classroom Context-Aware System

    ERIC Educational Resources Information Center

    Kuo, Yung-Lung; Lee, Jiann-Shu; Hsieh, Min-Chai

    2014-01-01

    Eye and head movements evoked in response to obvious visual attention shifts. However, there has been little progress on the causes of absent-mindedness so far. The paper proposes an attention awareness system that captures the conditions regarding the interaction of eye gaze and head pose under various attentional switching in computer classroom.…

  15. Object-based visual attention in 8-month-old infants: evidence from an eye-tracking study.

    PubMed

    Bulf, Hermann; Valenza, Eloisa

    2013-10-01

    Visual attention is one of the infant's primary tools for gathering relevant information from the environment for further processing and learning. The space-based component of visual attention in infants has been widely investigated; however, the object-based component of visual attention has received scarce interest. This scarcity is surprising, given the importance of objects in driving infants' attention and predispositions to attend to object information. Here, we investigated the object-based component of attention in 8-month-old infants. An eye tracker measured the saccade latencies to find a target that could appear in a previously cued end of 2 bars (valid targets), in the other end of the cued bar (invalid same-object targets), or in the other bar but at the same distance from the cue (invalid different-object targets). Bars were unoccluded or partly occluded; if attention is object based, it should also operate on objects that require perceptual completion. After verifying in a sample of adults (Experiment 1) that a measure of saccade latency suitably assessed space-based and object-based attention, we tested 8-month-old infants (Experiment 2) using the same procedure. The results showed that in both adults and infants, target detection was faster for valid targets than for invalid ones (space-based effect). Moreover, for both the unoccluded and partly occluded conditions, detection was faster on invalid within-object trials than on invalid between-objects trials (object-based effect). These findings demonstrate that visual objects can operate as units of attention for infants by the age of 8 months, offering implications for cognitive development.

  16. How to administer eye drops and eye ointment.

    PubMed

    Shaw, Mary

    2016-05-25

    Rationale and key points Eye drops and eye ointment are the mainstay of treatment of ocular conditions. Failure to prioritise administration of these medicines can prolong the condition and may present a risk to the patient's vision. ▶ Eye drops and eye ointments are used to treat acute and chronic conditions of the eye and surrounding structures. Eye drops must be instilled before applying eye ointment, since the ointment will affect the absorption of the eye drop. ▶ Nurses require knowledge of the technique, side effects and potential interactions associated with systemically or topically applied medicines to the eye to ensure patient safety and optimum outcomes. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How this article will change your practice. 2. How you intend to develop your knowledge and skills regarding treatment of ocular conditions. Subscribers can update their reflective accounts at rcni.com/portfolio.

  17. Classification of binary intentions for individuals with impaired oculomotor function: ‘eyes-closed’ SSVEP-based brain-computer interface (BCI)

    NASA Astrophysics Data System (ADS)

    Lim, Jeong-Hwan; Hwang, Han-Jeong; Han, Chang-Hee; Jung, Ki-Young; Im, Chang-Hwan

    2013-04-01

    Objective. Some patients suffering from severe neuromuscular diseases have difficulty controlling not only their bodies but also their eyes. Since these patients have difficulty gazing at specific visual stimuli or keeping their eyes open for a long time, they are unable to use the typical steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) systems. In this study, we introduce a new paradigm for SSVEP-based BCI, which can be potentially suitable for disabled individuals with impaired oculomotor function. Approach. The proposed electroencephalography (EEG)-based BCI system allows users to express their binary intentions without needing to open their eyes. A pair of glasses with two light emitting diodes flickering at different frequencies was used to present visual stimuli to participants with their eyes closed, and we classified the recorded EEG patterns in the online experiments conducted with five healthy participants and one patient with severe amyotrophic lateral sclerosis (ALS). Main results. Through offline experiments performed with 11 participants, we confirmed that human SSVEP could be modulated by visual selective attention to a specific light stimulus penetrating through the eyelids. Furthermore, the recorded EEG patterns could be classified with accuracy high enough for use in a practical BCI system. After customizing the parameters of the proposed SSVEP-based BCI paradigm based on the offline analysis results, binary intentions of five healthy participants were classified in real time. The average information transfer rate of our online experiments reached 10.83 bits min-1. A preliminary online experiment conducted with an ALS patient showed a classification accuracy of 80%. Significance. The results of our offline and online experiments demonstrated the feasibility of our proposed SSVEP-based BCI paradigm. It is expected that our ‘eyes-closed’ SSVEP-based BCI system can be potentially used for communication of

  18. Tear Film Stability in Sjögren Syndrome Patients Treated with Hyaluronic Acid Versus Crosslinked Hyaluronic Acid-Based Eye Drops.

    PubMed

    Cagini, Carlo; Torroni, Giovanni; Fiore, Tito; Cerquaglia, Alessio; Lupidi, Marco; Aragona, Pasquale; Iaccheri, Barbara

    2017-09-01

    To compare the stability of the tear film after instillation of eye drops containing hyaluronic acid (HA) or crosslinked hyaluronic acid (CLHA)-based in patients with Sjögren syndrome-related dry eye (SSDE). Forty subjects were included in this study and were divided into 2 groups: the first group (control group) consisted of 20 healthy volunteers; the second group (study group) constituted of 20 suffering from SSDE; before and 5, 30, and 60 min after instillation of eye drops the surface regularity index (SRI) and surface asymmetry index (SAI) were registered. Comparing HA and CLHA, in the control group, SAI show statistically significant difference in the time 0 and in time 5, whereas there is no a statistically significant difference after 30 and 60 min from instillation. For SRI there is no statistically significant difference at any time. In SSDE group there is no statistically significant difference in the time 0 and 5, whereas there is a statistically significant difference after 60 min for SAI, and after 30 and 60 min for SRI from instillation. Both SRI and SAI in dry eyes were significantly greater than in control eyes (P < 0.05). Our study showed a better efficacy of CLHA compared with HA in maintaining the stability of the tear film in a patient suffering from SSDE.

  19. Eye contricks

    PubMed Central

    Wade, Nicholas J

    2011-01-01

    Pictorial images are icons as well as eye-cons: they provide distillations of objects or ideas into simpler shapes. They create the impression of representing that which cannot be presented. Even at the level of the photograph, the links between icon and object are tenuous. The dimensions of depth and motion are missing from icons, and these alone introduce all manner of potential ambiguities. The history of art can be considered as exploring the missing link between icon and object. Eye-cons can also be illusions—tricks of vision so that what is seen does not necessarily correspond to what is physically presented. Pictorial images can be spatialised or stylised; spatialised images generally share some of the projective characteristics of the object represented. Written words are also icons, but they do not resemble the objects they represent—they are stylised or conventional. Icons as stylised words and spatialised images were set in delightful opposition by René Magritte in a series of pipe paintings, and this theme is here alluded to. Most of visual science is now concerned with icons—two-dimensional displays on computer monitors. Is vision now the science of eye-cons? PMID:23145240

  20. A Featured-Based Strategy for Stereovision Matching in Sensors with Fish-Eye Lenses for Forest Environments

    PubMed Central

    Herrera, Pedro Javier; Pajares, Gonzalo; Guijarro, Maria; Ruz, José J.; Cruz, Jesús M.; Montes, Fernando

    2009-01-01

    This paper describes a novel feature-based stereovision matching process based on a pair of omnidirectional images in forest stands acquired with a stereovision sensor equipped with fish-eye lenses. The stereo analysis problem consists of the following steps: image acquisition, camera modelling, feature extraction, image matching and depth determination. Once the depths of significant points on the trees are obtained, the growing stock volume can be estimated by considering the geometrical camera modelling, which is the final goal. The key steps are feature extraction and image matching. This paper is devoted solely to these two steps. At a first stage a segmentation process extracts the trunks, which are the regions used as features, where each feature is identified through a set of attributes of properties useful for matching. In the second step the features are matched based on the application of the following four well known matching constraints, epipolar, similarity, ordering and uniqueness. The combination of the segmentation and matching processes for this specific kind of sensors make the main contribution of the paper. The method is tested with satisfactory results and compared against the human expert criterion. PMID:22303134

  1. Quantification of changes in oil sands mining infrastructure land based on RapidEye and SPOT5

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Lantz, Nicholas; Guindon, Bert; Shipman, Todd; Chao, Dennis; Raymond, Don

    2013-10-01

    Natural resources development, spanning exploration, production and transportation activities, alters local land surface at various spatial scales. Quantification of these anthropogenic changes, both permanent and reversible, is needed for compliance assessment and for development of effective sustainable management strategies. Multi-spectral high resolution imagery data from SPOT5 and RapidEye were used for extraction and quantification of the anthropogenic and natural changes for a case study of Alberta bitumen (oil sands) mining located near Fort McMurray, Canada. Two test sites representative of the major Alberta bitumen production extraction processes, open pit and in-situ extraction, were selected. A hybrid change detection approach, combining pixel- and object-based target detection and extraction, is proposed based on Change Vector Analysis (CVA). The extraction results indicate that the changed infrastructure landscapes of these two sites have different footprints linked with their differing oil sands production processes. Pixeland object-based accuracy assessments have been applied for validation of the change detection results. For manmade disturbances, other than fine linear features such as the seismic lines, accuracies of about 80% have been achieved at the pixel level while, at the object level, these rise to 90-95%. Since many disturbance features are transient, the land surface changes by re-growth of vegetation and the capability for natural restoration on the mining sites have been assessed.

  2. Black Eye: First Aid

    MedlinePlus

    First aid Black eye: First aid Black eye: First aid By Mayo Clinic Staff A black eye is caused by bleeding under the skin around the eye. Most injuries that cause a black eye aren't serious. But a black eye ...

  3. Meeting report: the road to science-based policy - ESOF through the eyes of young scientists.

    PubMed

    Sinjab, Ansam; Nöske, Katharina

    2014-12-01

    Communication and common understanding between politicians, scientists, and the society can lead to evidence-based science policy, a core principle that guides high caliber research and open innovation for a sustainable future. © 2014 WILEY Periodicals, Inc.

  4. Autologous serum eye drops for dry eye

    PubMed Central

    Pan, Qing; Angelina, Adla; Zambrano, Andrea; Marrone, Michael; Stark, Walter J; Heflin, Thomas; Tang, Li; Akpek, Esen K

    2014-01-01

    Background Theoretically, autologous serum eye drops (AS) have a potential advantage over traditional therapies based on the assumption that AS serve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AS in dry eye treatment has gained popularity as a second-line therapy in the treatment of dry eye. Published studies on the subject indicate that autologous serum could be an effective treatment for dry eye. Objectives To evaluate the efficacy and safety of AS compared to artificial tears for treating dry eye. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLD MEDLINE, (January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to April 2013), the meta Register of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (September 2013) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013. Selection criteria We included randomized controlled trials (RCTs) in which AS was compared to artificial tears in the treatment of dry eye in adults. Data collection and analysis Two review authors independently screened all titles and abstracts and assessed full-text articles of potentially eligible trials. Two review authors extracted data and assessed the methodological quality and characteristics of the included trials.We contacted investigators for missing data

  5. Autologous serum eye drops for dry eye.

    PubMed

    Pan, Qing; Angelina, Adla; Zambrano, Andrea; Marrone, Michael; Stark, Walter J; Heflin, Thomas; Tang, Li; Akpek, Esen K

    2013-08-27

    =Theoretically, autologous serum eye drops (AS) have a potential advantage over traditional therapies based on the assumption that ASserve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AS in dry eye treatment has gained popularity as a second-line therapy in the treatment of dry eye.Published studies on the subject indicate that autologous serum could be an effective treatment for dry eye. To evaluate the efficacy and safety of AS compared to artificial tears for treating dry eye. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3),Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE,(January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences(LILACS) (January 1982 to April 2013), themetaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov(www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (September 2013) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013. We included randomized controlled trials (RCTs) in which AS was compared to artificial tears in the treatment of dry eye in adults. Two review authors independently screened all titles and abstracts and assessed full-text articles of potentially eligible trials. Two review authors extracted data and assessed the methodological quality and characteristics of the included trials.We contacted investigators for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95

  6. A MATLAB-based eye tracking control system using non-invasive helmet head restraint in the macaque.

    PubMed

    De Luna, Paolo; Mohamed Mustafar, Mohamed Faiz Bin; Rainer, Gregor

    2014-09-30

    Tracking eye position is vital for behavioral and neurophysiological investigations in systems and cognitive neuroscience. Infrared camera systems which are now available can be used for eye tracking without the need to surgically implant magnetic search coils. These systems are generally employed using rigid head fixation in monkeys, which maintains the eye in a constant position and facilitates eye tracking. We investigate the use of non-rigid head fixation using a helmet that constrains only general head orientation and allows some freedom of movement. We present a MATLAB software solution to gather and process eye position data, present visual stimuli, interact with various devices, provide experimenter feedback and store data for offline analysis. Our software solution achieves excellent timing performance due to the use of data streaming, instead of the traditionally employed data storage mode for processing analog eye position data. We present behavioral data from two monkeys, demonstrating that adequate performance levels can be achieved on a simple fixation paradigm and show how performance depends on parameters such as fixation window size. Our findings suggest that non-rigid head restraint can be employed for behavioral training and testing on a variety of gaze-dependent visual paradigms, reducing the need for rigid head restraint systems for some applications. While developed for macaque monkey, our system of course can work equally well for applications in human eye tracking where head constraint is undesirable. Copyright © 2014. Published by Elsevier B.V.

  7. Improving eye safety in citrus harvest crews through the acceptance of personal protective equipment, community-based participatory research, social marketing, and community health workers.

    PubMed

    Tovar-Aguilar, J Antonio; Monaghan, Paul F; Bryant, Carol A; Esposito, Andrew; Wade, Mark; Ruiz, Omar; McDermott, Robert J

    2014-01-01

    For the last 10 years, the Partnership for Citrus Workers Health (PCWH) has been an evidence-based intervention program that promotes the adoption of protective eye safety equipment among Spanish-speaking farmworkers of Florida. At the root of this program is the systematic use of community-based preventive marketing (CBPM) and the training of community health workers (CHWs) among citrus harvester using popular education. CBPM is a model that combines the organizational system of community-based participatory research (CBPR) and the strategies of social marketing. This particular program relied on formative research data using a mixed-methods approach and a multilevel stakeholder analysis that allowed for rapid dissemination, effective increase of personal protective equipment (PPE) usage, and a subsequent impact on adoptive workers and companies. Focus groups, face-to-face interviews, surveys, participant observation, Greco-Latin square, and quasi-experimental tests were implemented. A 20-hour popular education training produced CHWs that translated results of the formative research to potential adopters and also provided first aid skills for eye injuries. Reduction of injuries is not limited to the use of safety glasses, but also to the adoption of timely intervention and regular eye hygiene. Limitations include adoption in only large companies, rapid decline of eye safety glasses without consistent intervention, technological limitations of glasses, and thorough cost-benefit analysis.

  8. Quadcopter flight control using a low-cost hybrid interface with EEG-based classification and eye tracking.

    PubMed

    Kim, Byung Hyung; Kim, Minho; Jo, Sungho

    2014-08-01

    We propose a wearable hybrid interface where eye movements and mental concentration directly influence the control of a quadcopter in three-dimensional space. This noninvasive and low-cost interface addresses limitations of previous work by supporting users to complete their complicated tasks in a constrained environment in which only visual feedback is provided. The combination of the two inputs augments the number of control commands to enable the flying robot to travel in eight different directions within the physical environment. Five human subjects participated in the experiments to test the feasibility of the hybrid interface. A front view camera on the hull of the quadcopter provided the only visual feedback to each remote subject on a laptop display. Based on the visual feedback, the subjects used the interface to navigate along pre-set target locations in the air. The flight performance was evaluated by comparing with a keyboard-based interface. We demonstrate the applicability of the hybrid interface to explore and interact with a three-dimensional physical space through a flying robot.

  9. The Eyes Have It: A Problem-Based Learning Exercise in Molecular Evolution

    ERIC Educational Resources Information Center

    White, Harold B.

    2007-01-01

    Molecular evolution provides an interesting context in which to use problem-based learning because it integrates a variety of topics in biology, biochemistry, and molecular biology. This three-stage problem for advanced students deals with the structure, multiple functions, and properties of lactate dehydrogenase isozymes, and the related…

  10. The Eyes Have It: A Problem-Based Learning Exercise in Molecular Evolution

    ERIC Educational Resources Information Center

    White, Harold B.

    2007-01-01

    Molecular evolution provides an interesting context in which to use problem-based learning because it integrates a variety of topics in biology, biochemistry, and molecular biology. This three-stage problem for advanced students deals with the structure, multiple functions, and properties of lactate dehydrogenase isozymes, and the related…

  11. Conveying Clinical Reasoning Based on Visual Observation via Eye-Movement Modelling Examples

    ERIC Educational Resources Information Center

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nystrom, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Complex perceptual tasks, like clinical reasoning based on visual observations of patients, require not only conceptual knowledge about diagnostic classes but also the skills to visually search for symptoms and interpret these observations. However, medical education so far has focused very little on how visual observation skills can be…

  12. Conveying Clinical Reasoning Based on Visual Observation via Eye-Movement Modelling Examples

    ERIC Educational Resources Information Center

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nystrom, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2012-01-01

    Complex perceptual tasks, like clinical reasoning based on visual observations of patients, require not only conceptual knowledge about diagnostic classes but also the skills to visually search for symptoms and interpret these observations. However, medical education so far has focused very little on how visual observation skills can be…

  13. Project-Based Learning through the Eyes of Teachers and Students in Adult ESL Classrooms

    ERIC Educational Resources Information Center

    Petersen, Cristina; Nassaji, Hossein

    2016-01-01

    The use of projects and project-based learning has recently received much attention as a way of promoting meaning-focused communication and integrating different language skills into second and foreign language classrooms. However, perspectives on the effective implementation of projects have not been fully explored. This study examines and…

  14. Project-Based Learning through the Eyes of Teachers and Students in Adult ESL Classrooms

    ERIC Educational Resources Information Center

    Petersen, Cristina; Nassaji, Hossein

    2016-01-01

    The use of projects and project-based learning has recently received much attention as a way of promoting meaning-focused communication and integrating different language skills into second and foreign language classrooms. However, perspectives on the effective implementation of projects have not been fully explored. This study examines and…

  15. Co-morbidity of depression and anxiety in common age-related eye diseases: a population-based study of 662 adults

    PubMed Central

    Eramudugolla, Ranmalee; Wood, Joanne; Anstey, Kaarin J.

    2013-01-01

    This study examined the prevalence of co-morbid age-related eye disease and symptoms of depression and anxiety in late life, and the relative roles of visual function and disease in explaining symptoms of depression and anxiety. A community-based sample of 662 individuals aged over 70 years was recruited through the electoral roll. Vision was measured using a battery of tests including high and low contrast visual acuity, contrast sensitivity, motion sensitivity, stereoacuity, Useful Field of View, and visual fields. Depression and anxiety symptoms were measured using the Goldberg scales. The prevalence of self-reported eye disease [cataract, glaucoma, or age-related macular degeneration (AMD)] in the sample was 43.4%, with 7.7% reporting more than one form of ocular pathology. Of those with no eye disease, 3.7% had clinically significant depressive symptoms. This rate was 6.7% among cataract patients, 4.3% among those with glaucoma, and 10.5% for AMD. Generalized linear models adjusting for demographics, general health, treatment, and disability examined self-reported eye disease and visual function as correlates of depression and anxiety. Depressive symptoms were associated with cataract only, AMD, comorbid eye diseases and reduced low contrast visual acuity. Anxiety was significantly associated with self-reported cataract, and reduced low contrast visual acuity, motion sensitivity and contrast sensitivity. We found no evidence for elevated rates of depressive or anxiety symptoms associated with self-reported glaucoma. The results support previous findings of high rates of depression and anxiety in cataract and AMD, and in addition show that mood and anxiety are associated with objective measures of visual function independently of self-reported eye disease. The findings have implications for the assessment and treatment of mental health in the context of late-life visual impairment. PMID:24106477

  16. Co-morbidity of depression and anxiety in common age-related eye diseases: a population-based study of 662 adults.

    PubMed

    Eramudugolla, Ranmalee; Wood, Joanne; Anstey, Kaarin J

    2013-01-01

    This study examined the prevalence of co-morbid age-related eye disease and symptoms of depression and anxiety in late life, and the relative roles of visual function and disease in explaining symptoms of depression and anxiety. A community-based sample of 662 individuals aged over 70 years was recruited through the electoral roll. Vision was measured using a battery of tests including high and low contrast visual acuity, contrast sensitivity, motion sensitivity, stereoacuity, Useful Field of View, and visual fields. Depression and anxiety symptoms were measured using the Goldberg scales. The prevalence of self-reported eye disease [cataract, glaucoma, or age-related macular degeneration (AMD)] in the sample was 43.4%, with 7.7% reporting more than one form of ocular pathology. Of those with no eye disease, 3.7% had clinically significant depressive symptoms. This rate was 6.7% among cataract patients, 4.3% among those with glaucoma, and 10.5% for AMD. Generalized linear models adjusting for demographics, general health, treatment, and disability examined self-reported eye disease and visual function as correlates of depression and anxiety. Depressive symptoms were associated with cataract only, AMD, comorbid eye diseases and reduced low contrast visual acuity. Anxiety was significantly associated with self-reported cataract, and reduced low contrast visual acuity, motion sensitivity and contrast sensitivity. We found no evidence for elevated rates of depressive or anxiety symptoms associated with self-reported glaucoma. The results support previous findings of high rates of depression and anxiety in cataract and AMD, and in addition show that mood and anxiety are associated with objective measures of visual function independently of self-reported eye disease. The findings have implications for the assessment and treatment of mental health in the context of late-life visual impairment.

  17. Fly eye based sensor model and animation using matlab - biomed 2011.

    PubMed

    Anderson, Jeffrey R; Barrett, Steven F; Wright, Cameron H G

    2011-01-01

    A new optical sensor based on the common house fly, Musca domestica, has been under development for some time at the University of Wyoming. Each sensor consists of a series of photodiodes with overlapping Gaussian field of views. The photodiodes share a common facet lens. This type of sensor provides higher movement detection and resolution than can be obtained in current charged-couple detector (CCD) arrays that are commonly used in digital imaging systems. The purpose of this research is to aid in the application and development of the fly based sensor by creating a MATLAB simulation tool to model and study the response signals from various input stimuli. In particular, the sensor detection capability and limits for line, edge and pulse stimuli will be modeled, and analyzed. Increased knowledge of the detection characteristics and limits of this type of sensor will provide insight and guidance to determine possible sensor applications. The signal analysis makes use of the Gaussian profiles that are created in MATLAB. A user-selectable input signal can be applied, while observing the output signal. The information is animated, and plotted for study and analysis. This interactive MATLAB model is a powerful tool to help understand the complex interactions of the optical signals. This sensor configuration has a variety of applications in wheelchair odometry, power line detection by unmanned aerial systems (AES), high speed railroad line inspection, and remote building monitoring.

  18. Eye Examination Findings Among Children. United States.

    ERIC Educational Resources Information Center

    Health Services and Mental Health Administration (DHEW), Bethesda, MD.

    Reported were extensive statistical data on the prevalence of abnormal eye conditions found on examination, heterophoria test results, and history of eye problems as well as extent of interrelationship of the eye examination and vision test findings among children aged 6 to 11 years in the United States, based on findings from the Health…

  19. Line-feature-based calibration method of structured light plane parameters for robot hand-eye system

    NASA Astrophysics Data System (ADS)

    Qi, Yuhan; Jing, Fengshui; Tan, Min

    2013-03-01

    For monocular-structured light vision measurement, it is essential to calibrate the structured light plane parameters in addition to the camera intrinsic parameters. A line-feature-based calibration method of structured light plane parameters for a robot hand-eye system is proposed. Structured light stripes are selected as calibrating primitive elements, and the robot moves from one calibrating position to another with constraint in order that two misaligned stripe lines are generated. The images of stripe lines could then be captured by the camera fixed at the robot's end link. During calibration, the equations of two stripe lines in the camera coordinate system are calculated, and then the structured light plane could be determined. As the robot's motion may affect the effectiveness of calibration, so the robot's motion constraints are analyzed. A calibration experiment and two vision measurement experiments are implemented, and the results reveal that the calibration accuracy can meet the precision requirement of robot thick plate welding. Finally, analysis and discussion are provided to illustrate that the method has a high efficiency fit for industrial in-situ calibration.

  20. Tricolor R/G/B Laser Diode Based Eye-Safe White Lighting Communication Beyond 8 Gbit/s.

    PubMed

    Wu, Tsai-Chen; Chi, Yu-Chieh; Wang, Huai-Yung; Tsai, Cheng-Ting; Huang, Yu-Fang; Lin, Gong-Ru

    2017-12-01

    White light generation by mixing red, green, and blue laser diodes (RGB LDs) was demonstrated with Commission International de l'Eclairage coordinates of (0.2928, 0.2981), a correlated color temperature of 8382 K, and a color rendering index of 54.4 to provide a maximal illuminance of 7540 lux. All the white lights generated using RGB LDs were set within the risk group-1 criterion to avoid the blue-light hazard to human eyes. In addition, the RGB-LD mixed white light was diffused using a frosted glass to avoid optical aberration and to improve the performance of the lighting source. In addition, visible light communication (VLC) by using RGB-LD mixed white-light carriers and a point-to-point scheme over 1 m was performed in the directly modulated 16-QAM OFDM data format. In back-to-back transmission, the maximal allowable data rate at 10.8, 10.4, and 8 Gbps was determined for R, G, and B LDs, respectively. Moreover, the RGB-LD mixed white light-based indoor wavelength-division multiplexing (WDM)-VLC system yielded a total allowable transmission data rate of 8.8 Gbps over 0.5 m in free space. Such a high-speed RGB-LD mixed WDM-VLC system without any channel interference can be used to simultaneously provide data transmission and white lighting in an indoor environment.

  1. Synthesis and evaluation of simple naked-eye colorimetric chemosensors for anions based on azo dye-thiosemicarbazones

    NASA Astrophysics Data System (ADS)

    Radchatawedchakoon, Widchaya; Sangsuwan, Withsakorn; Kruanetr, Senee; Sakee, Uthai

    2014-03-01

    A series of novel, highly selective azo dye-thiosemicarbazones based anion sensors (3e-f) have been synthesized from the condensation reaction between thiosemicarbazide and six different azo salicylaldehydes. The structure of the sensors was confirmed by spectroscopic methods. The selectivity and sensitivity in the recognition for acetate anion over other anions such as fluoride, chloride, iodide and dihydrogenphosphate anions were determined by naked-eyes and UV-vis spectra. The color of the solution containing sensor had an obvious change from light yellow to orange only after the addition of acetate anion in aqueous solution (water/dimethylsulfoxide, 7:3, v/v) while other anions did not cause obvious color change. The anion recognition property of the receptor via proton-transfer is monitored by UV-vis titration and 1H NMR spectroscopy. Under condition in aqueous solution of sensor 3e (water/dimethylsulfoxide, 7:3, v/v), linearity range for the quantification of acetate anion was 1-22 μM and limit of detection (LOD) of acetate anion was 0.71 μM.

  2. Burn severity estimation using GeoEye imagery, object-based image analysis (OBIA), and Composite Burn Index (CBI) measurements

    NASA Astrophysics Data System (ADS)

    Dragozi, E.; Gitas, Ioannis Z.; Stavrakoudis, Dimitris G.; Minakou, C.

    2015-06-01

    Forest fires greatly influence the stability and functions of the forest ecosystems. The ever increasing need for accurate and detailed information regarding post-fire effects (burn severity) has led to several studies on the matter. In this study the combined use of Very High Resolution (VHR) satellite data (GeoEye), Objectbased image analysis (OBIA) and Composite Burn Index (CBI) measurements in estimating burn severity, at two different time points (2011 and 2012) is assessed. The accuracy of the produced maps was assessed and changes in burn severity between the two dates were detected using the post classification comparison approach. It was found that the produced burn severity map for 2011 was approximately 10% more accurate than that of 2012. This was mainly attributed to the increased heterogeneity of the study area in the second year, which led to an increased number of mixed class objects and consequently made it more difficult to spectrally discriminate between the severity classes. Following the post-classification analysis, the severity class changes were mainly attributed to the trees' ability to survive severe fire damage and sprout new leaves. Moreover, the results of the study suggest that when classifying CBI-based burn severity using VHR imagery it would be preferable to use images captured soon after the fire.

  3. Synthesis and evaluation of simple naked-eye colorimetric chemosensors for anions based on azo dye-thiosemicarbazones.

    PubMed

    Radchatawedchakoon, Widchaya; Sangsuwan, Withsakorn; Kruanetr, Senee; Sakee, Uthai

    2014-01-01

    A series of novel, highly selective azo dye-thiosemicarbazones based anion sensors (3e-f) have been synthesized from the condensation reaction between thiosemicarbazide and six different azo salicylaldehydes. The structure of the sensors was confirmed by spectroscopic methods. The selectivity and sensitivity in the recognition for acetate anion over other anions such as fluoride, chloride, iodide and dihydrogenphosphate anions were determined by naked-eyes and UV-vis spectra. The color of the solution containing sensor had an obvious change from light yellow to orange only after the addition of acetate anion in aqueous solution (water/dimethylsulfoxide, 7:3, v/v) while other anions did not cause obvious color change. The anion recognition property of the receptor via proton-transfer is monitored by UV-vis titration and (1)H NMR spectroscopy. Under condition in aqueous solution of sensor 3e (water/dimethylsulfoxide, 7:3, v/v), linearity range for the quantification of acetate anion was 1-22 μM and limit of detection (LOD) of acetate anion was 0.71 μM. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Quantification of anthropogenic and natural changes in oil sands mining infrastructure land based on RapidEye and SPOT5

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Guindon, Bert; Lantz, Nicholas; Shipman, Todd; Chao, Dennis; Raymond, Don

    2014-06-01

    Natural resources development, spanning exploration, production and transportation activities, alters local land surface at various spatial scales. Quantification of these anthropogenic changes, both permanent and reversible, is needed for compliance assessment and for development of effective sustainable management strategies. Multi-spectral high resolution imagery data from SPOT5 and RapidEye were used for extraction and quantification of the anthropogenic and natural changes for a case study of Alberta bitumen (oil sands) mining located in the Western Boreal Plains near Fort McMurray, Canada. Two test sites representative of the major Alberta bitumen production extraction processes, open pit and in situ extraction, were selected. A hybrid change detection approach, combining pixel- and object-based target detection and extraction, is proposed based on Change Vector Analysis (CVA). The extraction results indicate that the changed infrastructure landscapes of these two sites have different footprints linked with their differing oil sands production processes. Pixel- and object-based accuracy assessments have been applied for validation of the change detection results. For manmade disturbances, except for those fine linear features such as the seismic lines, accuracies of about 80% have been achieved at the pixel level while, at the object level, these rise to 90-95%. Since many disturbance features are transient, a new landscape index, entitled the Re-growth Index, has been formulated at single object level specifically to monitor restoration of these features to their natural state. It is found that the temporal behaviour of the Re-growth Index in an individual patch varies depending on the type of natural land cover. In addition, the Re-growth Index is also useful for assessing the detectability of disturbed sites.

  5. Driver face tracking using semantics-based feature of eyes on single FPGA

    NASA Astrophysics Data System (ADS)

    Yu, Ying-Hao; Chen, Ji-An; Ting, Yi-Siang; Kwok, Ngaiming

    2017-06-01

    Tracking driver's face is one of the essentialities for driving safety control. This kind of system is usually designed with complicated algorithms to recognize driver's face by means of powerful computers. The design problem is not only about detecting rate but also from parts damages under rigorous environments by vibration, heat, and humidity. A feasible strategy to counteract these damages is to integrate entire system into a single chip in order to achieve minimum installation dimension, weight, power consumption, and exposure to air. Meanwhile, an extraordinary methodology is also indispensable to overcome the dilemma of low-computing capability and real-time performance on a low-end chip. In this paper, a novel driver face tracking system is proposed by employing semantics-based vague image representation (SVIR) for minimum hardware resource usages on a FPGA, and the real-time performance is also guaranteed at the same time. Our experimental results have indicated that the proposed face tracking system is viable and promising for the smart car design in the future.

  6. Visual signal processing using fly-eye-based algorithm to detect the road edge

    NASA Astrophysics Data System (ADS)

    Truong, Nancy; Agassounon, William

    2007-04-01

    Rollover incidents of military vehicles have resulted in soldiers incurring injuries or losing their lives. A recent report identified that one cause of vehicle rollovers is the driver's inability to assess rollover threat, such as a cliff, soft ground, water, or culvert on the passenger side of the vehicle. The vehicle's width hinders the driver's field of view. To reduce the number of military vehicles rolling over, a road edge detection and driver warning system is being developed to warn the driver of potential rollover threats and keep the driver from veering off the side of the road. This system utilizes a unique, ultra-fast, image-processing algorithm based on the neurobiology of insect vision, specifically fly vision. The system consists of a Long-Wavelength Infrared (LWIR) camera and visible spectrum monochrome video camera system, a long-range laser scanner, a processing module in which a biomimetic image processor detects road edges in real-time, and a Driver's Vision Enhancer (DVE) which displays the road image, detected boundaries and road-side terrain steepness in real-time for the driver.

  7. Eye-gaze independent EEG-based brain-computer interfaces for communication

    NASA Astrophysics Data System (ADS)

    Riccio, A.; Mattia, D.; Simione, L.; Olivetti, M.; Cincotti, F.

    2012-08-01

    The present review systematically examines the literature reporting gaze independent interaction modalities in non-invasive brain-computer interfaces (BCIs) for communication. BCIs measure signals related to specific brain activity and translate them into device control signals. This technology can be used to provide users with severe motor disability (e.g. late stage amyotrophic lateral sclerosis (ALS); acquired brain injury) with an assistive device that does not rely on muscular contraction. Most of the studies on BCIs explored mental tasks and paradigms using visual modality. Considering that in ALS patients the oculomotor control can deteriorate and also other potential users could have impaired visual function, tactile and auditory modalities have been investigated over the past years to seek alternative BCI systems which are independent from vision. In addition, various attentional mechanisms, such as covert attention and feature-directed attention, have been investigated to develop gaze independent visual-based BCI paradigms. Three areas of research were considered in the present review: (i) auditory BCIs, (ii) tactile BCIs and (iii) independent visual BCIs. Out of a total of 130 search results, 34 articles were selected on the basis of pre-defined exclusion criteria. Thirteen articles dealt with independent visual BCIs, 15 reported on auditory BCIs and the last six on tactile BCIs, respectively. From the review of the available literature, it can be concluded that a crucial point is represented by the trade-off between BCI systems/paradigms with high accuracy and speed, but highly demanding in terms of attention and memory load, and systems requiring lower cognitive effort but with a limited amount of communicable information. These issues should be considered as priorities to be explored in future studies to meet users’ requirements in a real-life scenario.

  8. Eye-gaze independent EEG-based brain-computer interfaces for communication.

    PubMed

    Riccio, A; Mattia, D; Simione, L; Olivetti, M; Cincotti, F

    2012-08-01

    The present review systematically examines the literature reporting gaze independent interaction modalities in non-invasive brain-computer interfaces (BCIs) for communication. BCIs measure signals related to specific brain activity and translate them into device control signals. This technology can be used to provide users with severe motor disability (e.g. late stage amyotrophic lateral sclerosis (ALS); acquired brain injury) with an assistive device that does not rely on muscular contraction. Most of the studies on BCIs explored mental tasks and paradigms using visual modality. Considering that in ALS patients the oculomotor control can deteriorate and also other potential users could have impaired visual function, tactile and auditory modalities have been investigated over the past years to seek alternative BCI systems which are independent from vision. In addition, various attentional mechanisms, such as covert attention and feature-directed attention, have been investigated to develop gaze independent visual-based BCI paradigms. Three areas of research were considered in the present review: (i) auditory BCIs, (ii) tactile BCIs and (iii) independent visual BCIs. Out of a total of 130 search results, 34 articles were selected on the basis of pre-defined exclusion criteria. Thirteen articles dealt with independent visual BCIs, 15 reported on auditory BCIs and the last six on tactile BCIs, respectively. From the review of the available literature, it can be concluded that a crucial point is represented by the trade-off between BCI systems/paradigms with high accuracy and speed, but highly demanding in terms of attention and memory load, and systems requiring lower cognitive effort but with a limited amount of communicable information. These issues should be considered as priorities to be explored in future studies to meet users' requirements in a real-life scenario.

  9. Validation of a paleo river system derived by ground based electromagnetic induction measurements with satellite based RapidEye images

    NASA Astrophysics Data System (ADS)

    Rudolph, Sebastian; von Hebel, Christian; Ali, Mohammed; Stadler, Anja; Herbst, Michael; Montzka, Carsten; Pätzold, Stefan; Weihermüller, Lutz; van der Kruk, Jan; Vereecken, Harry

    2013-04-01

    Morphological remnants of an inactive river system that has been filled by younger sediments can provide datable proxies about past climatic conditions. However, sediment composition of their infillings is a challenge for agriculture, in particular for precision agriculture. Differential crop development and yield reduction are often a consequence of lateral and vertical textural inhomogeneities. Several studies have shown that buried river systems can be traced by the use of remote sensing. However, the appearance of crop marks strongly depends on environmental conditions, and therefore, the reliance of remotely acquired data can become time and cost expensive. Soil physical properties which are related to textural differences can be mapped fast and cost-effective by the use of near surface geophysics. Especially electromagnetic induction (EMI), which measures soil apparent conductivity (ECa), has become a tool of choice to characterize large areas in high resolution. The introduction of multiple coil EMI systems as well as the quantification of respective measurements enables a reliable multilayer inversion. The aim of this study was to map a postglacial river system on agricultural fields and to mark out buried remains such as trenches and bomb craters of World War II. In summer 2012 ten fields (17 ha) were mapped with the CMD MiniExplorer, a multiple coil EMI system especially appropriate for near surface applications, after the harvest of winter wheat and sugar beet. At elevated sandy sites meander like patterns with higher conductivity were mapped. ECa measurements were verified by textural data taken from directed soil samples and vertical ECa logs. Sediment thickness was evaluated on soil cores and electrical resistivity tomography (ERT) transects. Furthermore, ERT quantified ECa measurements were correlated with satellite as well as destructive derived leaf area index (LAI) measurements. In 3 of 71 LAI maps derived by multispectral RapidEye imagery crop

  10. Making a photomap of the human eye based on the spherical shape of its sclera and the circular contour of its iris

    NASA Astrophysics Data System (ADS)

    Ethrog, U.

    Iridology was defined as a method of diagnostic used in alternative medicine to analyze health status by studying colors, marks and signs in the sclera of the eye which according to iridologists can be demarcated into zones corresponding to parts of the human body. These are then made into "iridology charts" for comparison with photo images of a patient's eyes. Due to the large tilt angles of the images relative to the eye's geometrical axis, accurate comparison is not possible, and this paper suggests the use of photogrammetric methods for making a photomap for each of the patient's eyes which is then compared to its respective iridology chart. Because of the small overlapping area between any two successive images (about 20%) and the lack of control points, we were prevented from using conventional photogrammetric methods and instead had to develop an alternative photogrammetric method based on the spherical shape of the sclera and the circular shape of the iris contour. Accuracy tests showed that this method is relatively accurate and has small residuals following the process of bundle adjustment.

  11. Appositional Closure Identified by Ultrasound Biomicroscopy in Population-Based Primary Angle-Closure Glaucoma Suspects: The Liwan Eye Study

    PubMed Central

    Kong, Xiangbin; Foster, Paul J.; Huang, Qunxiao; Zheng, Yingfeng; Huang, Wenyong; Cai, Xiaoyu

    2011-01-01

    Purpose. To describe the characteristics of the iridocorneal angle using ultrasound biomicroscopy (UBM) in Chinese people classified gonioscopically as having suspected primary angle-closure (PACS) glaucoma. Methods. PACS were defined as not having visible posterior (usually pigmented) trabecular meshwork in two or more quadrants examined by static gonioscopy. The PACS and 1 of 10 those who did not meet this criterion were identified from a population-based survey. Iridotrabecular meshwork contact (ITC) was identified and further classified into low and high, according to standard UBM images. Those with high ITC were further classified according the configuration of ITC: B-type, with contiguous ITC from the base of the angle, and S-type, with ITC localized to the region of Schwalbe's line. Results. ITC was identified in 78.6% of the superior, 40.2% of the nasal, 59.8% of the inferior, and 25.6% of the temporal quadrants in the PACS (n = 117). These proportions were 43.9%, 15.8%, 29.8%, and 14.0% in the controls (n = 57), respectively. About two thirds of the eyes with ITC were classified as high. In those with high ITC, the number with B- and S-type ITC was very similar. The proportions of any high ITCs increased substantially from 15.4% in those with Shaffer angle grade 4 and 45.0% in grade 3, to 71.0% in grade 2, 70.2% in grade 1, and 86.4% in grade 0. Conclusions. More ITC is identified on UBM imaging than by gonioscopy. Careful consideration should be given to the assessment modality regarded as the reference standard in defining anatomic risk factors for glaucomatous visual loss and the need for treatment. PMID:21357394

  12. Billie's eyes.

    PubMed

    Dunning, S E

    1993-03-01

    The author, a nurse, is personally opposed to abortion; however, her earlier encounter with a victim of an illegal abortion has prevented her from joining campaigns to reinstate bans on abortion rights. The woman, "Billie," presented to an inner-city Chicago hospital in 1970 with hemorrhaging. She had delayed going for treatment because she feared being imprisoned for having obtained an abortion. She rapidly entered septic shock, with hypotension, confusion, and hallucinations. Physicians removed her infected uterus and ovaries. Subsequent kidney failure necessitated the transfer of this young woman to another hospital where she could receive dialysis. The author was unable to obtain follow-up information on whether Billie survived. She remains haunted by the memory of Billie's wide, frightened eyes as she was placed in the ambulance. It is this memory, and the knowledge that desperate women like Billie will find someone, somewhere to perform an illegal abortion, that is behind the author's reluctant support for the right to choose.

  13. Factors Associated with Disability in Rural Bangladesh: Bangladesh Population-Based Diabetes and Eye Study (BPDES).

    PubMed

    Islam, Fakir M Amirul; Bhowmik, Jahar L; Islam, Silvia Z; Renzaho, Andre M N; Hiller, Janet E

    2016-01-01

    To assess factors associated with disability in a rural district of Bangladesh. Using a population-based systematic sampling technique, data were collected from 3104 adults aged ≥ 30 years from the Banshgram union of Narail district. Data collected included an interviewer administered questionnaire to report physical disabilities including impairment that prevents engagement with paid work, visual, hearing, and mobility as well as mental disabilities. Socio-demographic and anthropometric factors including educational attainment and body mass index, as well as clinical factors such as blood pressure, and fasting blood glucose were also collected. Binary and multinomial logistic regression techniques were used to explore the association of various socio-demographic and clinical factors with disability. The mean (SD), minimum and maximum ages of the participants were 51 (12), 30 and 89 years. Of total participants, 65% were female. The prevalence of disability varied from 29.1% for visual impairment (highest) to 16.5% for hearing, 14.7% for movement difficulties and 1.6% (lowest) for any other disability that prevented engagement with paid work. Overall, the prevalence of a single disability was 28.6% and that of two or more disabilities was 14.7%. Older age, gender (female), lower socio-economic status (SES), and hypertension were associated with a higher prevalence of most of the disability components. The prevalence of hearing problems (24.5% vs. 13.3%, p<0.001) and movement difficulties (24.9% vs. 13.0%, p<0.001) was significantly higher among lower-income participants than their higher-income counterparts after controlling for age. Prevalence of visual impairment (54.6% vs. 9.2%, p<0.001), hearing (32.2% vs. 6.7%, p<0.001) and movement difficulties (29.2% vs. 5.5%, p<0.001) were significantly higher in people of aged 60 years or older than those aged 30-34 years. After multivariate adjustment, the prevalence of single disability (prevalence risk ratio [PRR] 1

  14. Factors Associated with Disability in Rural Bangladesh: Bangladesh Population-Based Diabetes and Eye Study (BPDES)

    PubMed Central

    Islam, Fakir M. Amirul; Bhowmik, Jahar L.; Islam, Silvia Z.; Renzaho, Andre M. N.; Hiller, Janet E.

    2016-01-01

    Background To assess factors associated with disability in a rural district of Bangladesh. Methods Using a population-based systematic sampling technique, data were collected from 3104 adults aged ≥ 30 years from the Banshgram union of Narail district. Data collected included an interviewer administered questionnaire to report physical disabilities including impairment that prevents engagement with paid work, visual, hearing, and mobility as well as mental disabilities. Socio-demographic and anthropometric factors including educational attainment and body mass index, as well as clinical factors such as blood pressure, and fasting blood glucose were also collected. Binary and multinomial logistic regression techniques were used to explore the association of various socio-demographic and clinical factors with disability. Results The mean (SD), minimum and maximum ages of the participants were 51 (12), 30 and 89 years. Of total participants, 65% were female. The prevalence of disability varied from 29.1% for visual impairment (highest) to 16.5% for hearing, 14.7% for movement difficulties and 1.6% (lowest) for any other disability that prevented engagement with paid work. Overall, the prevalence of a single disability was 28.6% and that of two or more disabilities was 14.7%. Older age, gender (female), lower socio-economic status (SES), and hypertension were associated with a higher prevalence of most of the disability components. The prevalence of hearing problems (24.5% vs. 13.3%, p<0.001) and movement difficulties (24.9% vs. 13.0%, p<0.001) was significantly higher among lower-income participants than their higher-income counterparts after controlling for age. Prevalence of visual impairment (54.6% vs. 9.2%, p<0.001), hearing (32.2% vs. 6.7%, p<0.001) and movement difficulties (29.2% vs. 5.5%, p<0.001) were significantly higher in people of aged 60 years or older than those aged 30–34 years. After multivariate adjustment, the prevalence of single disability

  15. Formation of the hurricane eye

    NASA Astrophysics Data System (ADS)

    Vigh, Jonathan L.

    This dissertation consists of three distinct studies which investigate aspects of eye formation. The first study reviews eye phenomenon in a variety of vortices ranging from simple vortices to the menagerie of geophysical vortices, emphasizing similarities and differences to the eyes formed in hurricanes. The hurricane eye is found to be a paradoxical structure imposed by conservation of angular momentum and the boundaries of the vortex. A comprehensive definition for hurricane eye formation is proposed and various eye formation mechanisms are summarized. The next study presents a simple theoretical argument to isolate the conditions under which a tropical cyclone can rapidly develop a warm-core thermal structure and subsequently approach a steady state. The theoretical argument is based on the balanced vortex model and, in particular, on the associated transverse circulation equation and the geopotential tendency equation. The transverse circulation and the temperature tendency in a tropical vortex depend not only on the diabatic forcing, but also on the spatial distributions of the static stability, the baroclinity, and the inertial stability. The vortex response to diabatic heating depends critically on whether the heating occurs in the low inertial stability region outside the radius of maximum wind or in the high inertial stability region inside the radius of maximum wind. This result suggests that rapid intensification is favored for storms which have at least some of the eyewall convection inside the radius of maximum wind. The development of an eye partially removes diabatic heating from the high inertial stability region of the storm center, yet rapid intensification may continue if the eyewall heating continues to become more efficient. As the warm core matures and static stability increases over the inner core, conditions there become less favorable for deep upright convection and the storm tends to approach a steady state. The final study characterizes

  16. A new cell-based method for assessing the eye irritation potential of chemicals: an alternative to the Draize test.

    PubMed

    Cho, Sun-A; An, Susun; Lee, Eunyoung; Shin, Kyeho; Cho, Jun-Cheol; Lee, Tae Ryong

    2012-07-20

    Using a human corneal cell line (HCE-T cells) and 2 evaluation criteria, we developed a new alternative method to assess the eye irritation potential of chemicals. We exposed HCE-T cells to different concentrations of 38 chemicals for 1h and measured relative cell viability (RCV) as an endpoint at each concentration. Using the RCV values, we calculated the RCV50. We also exposed HCE-T cells to 3 fixed concentrations of the 38 chemicals (5%, 0.5%, and 0.05%) for 1h and measured the RCV at each concentration. Using the RCV values at 5%, 0.5%, and 0.05%, we developed a new criterion for eye irritation potential (total eye irritation score, TEIS) and estimated the ocular irritancy. We then assessed the correlation of the results of RCV50 and TEIS with those of the Draize rabbit eye irritation. Both the RCV50 and TEIS results exhibited good positive correlations (sensitivity: 80.77%, specificity: 83.33%, and accuracy: 81.58% for TEIS; sensitivity: 73.08-76.92%, specificity: 75.00%, and accuracy: 73.68-76.32% for RCV50). We conclude that the new in vitro model using HCE-T cells is a good alternative evaluation model for the prediction of the eye irritation potential of chemicals. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Numerical study on statistical properties of speckle pattern in laser projection display based on human eye model

    NASA Astrophysics Data System (ADS)

    Cui, Zhe; Wang, Anting; Ma, Qianli; Ming, Hai

    2013-12-01

    In this paper, the laser speckle pattern on human retina for a laser projection display is simulated. By introducing a specific eye model `Indiana Eye', the statistical properties of the laser speckle are numerical investigated. The results show that the aberrations of human eye (mostly spherical and chromatic) will decrease the speckle contrast felt by people. When the wavelength of the laser source is 550 nm (green), people will feel the strongest speck pattern and the weakest when the wavelength is 450 nm (blue). Myopia and hyperopia will decrease the speckle contrast by introducing large spherical aberrations. Although aberration is good for speckle reduction, but it will degrade the imaging capability of the eye. The results show that laser source (650 nm) will have the best image quality on the retina. At last, we compare the human eye with an aberration-free imaging system. Both the speckle contrast and the image quality appear different behavior in these two imaging systems. The results are useful when a standardized measurement procedure for speckle contrast needs to be built.

  18. Adaptive optics for reduced threshold energy in femtosecond laser induced optical breakdown in water based eye model

    NASA Astrophysics Data System (ADS)

    Hansen, Anja; Krueger, Alexander; Ripken, Tammo

    2013-03-01

    In ophthalmic microsurgery tissue dissection is achieved using femtosecond laser pulses to create an optical breakdown. For vitreo-retinal applications the irradiance distribution in the focal volume is distorted by the anterior components of the eye causing a raised threshold energy for breakdown. In this work, an adaptive optics system enables spatial beam shaping for compensation of aberrations and investigation of wave front influence on optical breakdown. An eye model was designed to allow for aberration correction as well as detection of optical breakdown. The eye model consists of an achromatic lens for modeling the eye's refractive power, a water chamber for modeling the tissue properties, and a PTFE sample for modeling the retina's scattering properties. Aberration correction was performed using a deformable mirror in combination with a Hartmann-Shack-sensor. The influence of an adaptive optics aberration correction on the pulse energy required for photodisruption was investigated using transmission measurements for determination of the breakdown threshold and video imaging of the focal region for study of the gas bubble dynamics. The threshold energy is considerably reduced when correcting for the aberrations of the system and the model eye. Also, a raise in irradiance at constant pulse energy was shown for the aberration corrected case. The reduced pulse energy lowers the potential risk of collateral damage which is especially important for retinal safety. This offers new possibilities for vitreo-retinal surgery using femtosecond laser pulses.

  19. A first approach to a neuropsychological screening tool using eye-tracking for bedside cognitive testing based on the Edinburgh Cognitive and Behavioural ALS Screen.

    PubMed

    Keller, Jürgen; Krimly, Amon; Bauer, Lisa; Schulenburg, Sarah; Böhm, Sarah; Aho-Özhan, Helena E A; Uttner, Ingo; Gorges, Martin; Kassubek, Jan; Pinkhardt, Elmar H; Abrahams, Sharon; Ludolph, Albert C; Lulé, Dorothée

    2017-08-01

    Reliable assessment of cognitive functions is a challenging task in amyotrophic lateral sclerosis (ALS) patients unable to speak and write. We therefore present an eye-tracking based neuropsychological screening tool based on the Edinburgh Cognitive and Behavioural ALS Screen (ECAS), a standard screening tool for cognitive deficits in ALS. In total, 46 ALS patients and 50 healthy controls matched for age, gender and education were tested with an oculomotor based and a standard paper-and-pencil version of the ECAS. Significant correlation between both versions was observed for ALS patients and healthy controls in the ECAS total score and in all of its ALS-specific domains (all r > 0.3; all p < 0.05). The eye-tracking version of the ECAS reliably distinguished between ALS patients and healthy controls in the ECAS total score (p < 0.05). Also, cognitively impaired and non-impaired patients could be reliably distinguished with a specificity of 95%. This study provides first evidence that the eye-tracking based ECAS version is a promising approach for assessing cognitive deficits in ALS patients who are unable to speak or write.

  20. Eye Injuries (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Eye Injuries KidsHealth > For Parents > Eye Injuries Print A ... sand, dirt, and other foreign bodies on the eye surface) Wash your hands thoroughly before touching the ...

  1. Diabetes - eye care

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000078.htm Diabetes - eye care To use the sharing features on this ... prevent them from getting worse. You Need Regular eye Exams Every year, you should have an eye ...

  2. Eye muscle repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  3. Eye Cosmetic Safety

    MedlinePlus

    ... when they are new. FDA has an Import Alert in effect for cosmetics -- including eye cosmetics -- contaminated ... in the area of the eye. An import alert for cosmetics containing illegal colors lists several eye ...

  4. Dilating Eye Drops

    MedlinePlus

    ... sometimes used to treat eye diseases, such as amblyopia and inflammation. How long do dilating drops last? ... used to treat certain eye diseases, such as amblyopia and inflammation in the eye. These therapeutic dilating ...

  5. Assessment of IrisPlex-based multiplex for eye and skin color prediction with application to a Portuguese population.

    PubMed

    Dario, Paulo; Mouriño, Helena; Oliveira, Ana Rita; Lucas, Isabel; Ribeiro, Teresa; Porto, Maria João; Costa Santos, Jorge; Dias, Deodália; Corte Real, Francisco

    2015-11-01

    DNA phenotyping research is one of the most emergent areas of forensic genetics. Predictions of externally visible characteristics are possible through analysis of single nucleotide polymorphisms. These tools can provide police with "intelligence" in cases where there are no obvious suspects and unknown biological samples found at the crime scene do not result in any criminal DNA database hits. IrisPlex, an eye color prediction assay, revealed high prediction rates for blue and brown eye color in European populations. However, this is less predictive in some non-European populations, probably due to admixing. When compared to other European countries, Portugal has a relatively admixed population, resulting from a genetic influx derived from its proximity to and historical relations with numerous African territories. The aim of this work was to evaluate the utility of IrisPlex in the Portuguese population. Furthermore, the possibility of supplementing this multiplex with additional markers to also achieve skin color prediction within this population was evaluated. For that, IrisPlex was augmented with additional SNP loci. Eye and skin color prediction was estimated using the multinomial logistic regression and binomial logistic regression models, respectively. The results demonstrated eye color prediction accuracies of the IrisPlex system of 90 and 60% for brown and blue eye color, respectively, and 77% for intermediate eye color, after allele frequency adjustment. With regard to skin color, it was possible to achieve a prediction accuracy of 93%. In the future, phenotypic determination multiplexes must include additional loci to permit skin color prediction as presented in this study as this can be an advantageous tool for forensic investigation.

  6. Rapid eye movement sleep behaviour disorder in young- and older-onset Parkinson disease: a questionnaire-based study.

    PubMed

    Mahale, R; Yadav, R; Pal, P K

    2014-06-01

    Rapid eye movement sleep behavior disorder (RBD) is common in Parkinson disease (PD). To determine the frequency of clinically probable RBD (cpRBD) in young-onset (21 to < or =40 years; YOPD) and older-onset PD (>40 years; OOPD) and characterize its pattern. A total of 156 patients with PD (YOPD-51, OOPD-105) were clinically examined and the presence of RBD was diagnosed using the minimal criteria for diagnosis of RBD (International Classification of Sleep Disorders, ICSD-1). RBD screening questionnaire based on the minimal criteria was used. The bed-partners were also interviewed with Mayo sleep questionnaire. Other scales included Unified Parkinson Disease Rating Scale part III (UPDRS III), Hoehn & Yahr stage, Mini Mental Status Examination, Pittsburgh Sleep Quality Index, Parkinson Disease Sleep Scale, Epworth Sleep Scale, Hamilton Anxiety Rating Scale and Hamilton Depression Rating Scale. cpRBD was diagnosed in 30 (19.2%) patients, majority being OOPD rather than YOPD (86.7% vs. 13.3%; P=0.01). The frequency of RBD was significantly higher (P=0.016) in OOPD (24.8%) compared to those with YOPD (7.8%). Most often (72.4%) RBD occurred after the onset of parkinsonian symptoms. RBD was independently associated with higher global PSQI scores, total ESS scores and total PDSS scores after adjusting for the effects of age, gender, Hoehn & Yahr stage and duration of illness. Patients with RBD were older with later-onset motor symptoms, a more advanced stage, poorer sleep quality, and more frequent daytime sleepiness. Older-onset PD had a higher frequency of RBD than young-onset PD. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Function and visual impairment in a population-based study of older adults. The SEE project. Salisbury Eye Evaluation.

    PubMed

    West, S K; Munoz, B; Rubin, G S; Schein, O D; Bandeen-Roche, K; Zeger, S; German, S; Fried, L P

    1997-01-01

    The Salisbury Eye Evaluation (SEE) project investigates the impact of vision on functional status in a population-based sample of elderly persons. The prevalence of self-reports of functional status and the association with visual acuity loss are described. A random sample of men and women 65 to 84 years of age from Salisbury, Maryland were recruited for home interviews and clinic examinations. Of the eligible sample, 78% responded to the home questionnaire and 65% responded to the questionnaire and the clinic examination. Binocular visual acuity of each person was measured using ETDRS charts and protocols. Questions were asked concerning activities of daily living, instrumental activities of daily living, physical function, social interaction, and activities of daily vision. Analyses of the association of presenting visual acuity worse than 20/40 with the measures of function were carried out and adjusted for age, race, and sex. All measures of functional status showed a decline with age; women and blacks were more likely to report difficulties. The age-adjusted proportions of those with visual impairment were not significantly different between men and women (7.2% versus 6.7%; P = 0.60). Black persons had almost twice the rate (10.4%) of white persons (5.6%; P < 0.001). Age, race, gender, and visual impairment were all significantly related to declines in functional status in multivariate models. Data on functional status in the project population were similar to national data and confirmed higher rates of disability in women and blacks. Binocular visual acuity worse than 20/40 appeared to have an impact on all the self-report measures of functional status. Further analyses on the interaction of vision with other comorbid conditions on function status clearly are indicated.

  8. Evaluating Experience-Based Geologic Field Instruction: Lessons Learned from A Large-Scale Eye-Tracking Experiment

    NASA Astrophysics Data System (ADS)

    Tarduno, J. A.; Walders, K.; Bono, R. K.; Pelz, J.; Jacobs, R.

    2015-12-01

    A course centered on experience-based learning in field geology has been offered ten times at the University of Rochester. The centerpiece of the course is a 10-day field excursion to California featuring a broad cross-section of the geology of the state, from the San Andreas Fault to Death Valley. Here we describe results from a large-scale eye-tracking experiment aimed at understanding how experts and novices acquire visual geologic information. One ultimate goal of the project is to determine whether expert gaze patterns can be quantified to improve the instruction of beginning geology students. Another goal is to determine if aspects of the field experience can be transferred to the classroom/laboratory. Accordingly, ultra-high resolution segmented panoramic images have been collected at key sites visited during the field excursion. We have found that strict controls are needed in the field to obtain meaningful data; this often involves behavior atypical of geologists (e.g. limiting the field of view prior to data collection and placing time limits on scene viewing). Nevertheless some general conclusions can be made from a select data set. After an initial quick search, experts tend to exhibit scanning behavior that appears to support hypothesis testing. Novice fixations appear to define a scattered search pattern and/or one distracted by geologic noise in a scene. Noise sources include modern erosion features and vegetation. One way to quantify noise is through the use of saliency maps. With the caveat that our expert data set is small, our preliminary analysis suggests that experts tend to exhibit top-down behavior (indicating hypothesis driven responses) whereas novices show bottom-up gaze patterns, influenced by more salient features in a scene. We will present examples and discuss how these observations might be used to improve instruction.

  9. Sensitive naked-eye detection of Hg2+ based on the aggregation and filtration of thymine functionalized vesicles caused by selective interaction between thymine and Hg2+.

    PubMed

    Ma, Xue; Sheng, Zhonghan; Jiang, Long

    2014-07-07

    We report a sensitive, selective and low-cost method for the naked-eye detection of Hg(2+). The principle is based on rapid interaction between functionalized PDA vesicles and Hg(2+), which leads to obvious aggregation of vesicles. Furthermore, using only a simple filtration process, without using any other color indicator or specialized equipment, a higher detection sensitivity for Hg(2+) (0.1 μM) than chromophoric colorimetric sensors (approximately 1-100 μM) was obtained.

  10. Eyeing Ganymede

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Jupiter casts a baleful eye toward the moon Ganymede in this enhanced-contrast image from NASA's Cassini spacecraft.

    Jupiter's 'eye', the Great Red Spot, was captured just before disappearing around the eastern edge of the planet. The furrowed eyebrow above and to the left of the spot is a turbulent wake region caused by westward flow that has been deflected to the north and around the Red Spot. The smallest features visible are about 240 kilometers (150 miles) across.

    Within the band south of the Red Spot are a trio of white ovals, high pressure counterclockwise-rotating regions that are dynamically similar to the Red Spot. The dark filamentary features interspersed between white ovals are probably cyclonic circulations and, unlike the ovals, are rotating clockwise.

    Jupiter's equatorial zone stretching across the planet north of the Spot appears bright white, with gigantic plume clouds spreading out from the equator both to the northeast and to the southeast in a chevron pattern. This zone looks distinctly different than it did during the Voyager flyby 21 years ago. Then, its color was predominantly brown and the only white plumes conspicuous against the darker material beneath them were oriented southwest-to-northeast.

    Ganymede is Jupiter's largest moon, about 50 percent larger than our own Moon and larger than the planet Mercury. The visible details in this image are different geological terrains. Dark areas tend to be older and heavily cratered; brighter areas are younger and less cratered. Cassini images of Ganymede and Jupiter's other large moons taken near closest approach on Dec. 30 will have resolutions about four times better than that seen here.

    This image is a color composite of ones taken with different filters by Cassini's narrow-angle camera on Nov. 18, 2000, processed to enhance contrast. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of

  11. Near-infrared spectroscopy (NIRS)-based eyes-closed brain-computer interface (BCI) using prefrontal cortex activation due to mental arithmetic

    PubMed Central

    Shin, Jaeyoung; Müller, Klaus-R; Hwang, Han-Jeong

    2016-01-01

    We propose a near-infrared spectroscopy (NIRS)-based brain-computer interface (BCI) that can be operated in eyes-closed (EC) state. To evaluate the feasibility of NIRS-based EC BCIs, we compared the performance of an eye-open (EO) BCI paradigm and an EC BCI paradigm with respect to hemodynamic response and classification accuracy. To this end, subjects performed either mental arithmetic or imagined vocalization of the English alphabet as a baseline task with very low cognitive loading. The performances of two linear classifiers were compared; resulting in an advantage of shrinkage linear discriminant analysis (LDA). The classification accuracy of EC paradigm (75.6 ± 7.3%) was observed to be lower than that of EO paradigm (77.0 ± 9.2%), which was statistically insignificant (p = 0.5698). Subjects reported they felt it more comfortable (p = 0.057) and easier (p < 0.05) to perform the EC BCI tasks. The different task difficulty may become a cause of the slightly lower classification accuracy of EC data. From the analysis results, we could confirm the feasibility of NIRS-based EC BCIs, which can be a BCI option that may ultimately be of use for patients who cannot keep their eyes open consistently. PMID:27824089

  12. A Population-Based Assessment of the Agreement Between Grading of Goniophotographic Images and Gonioscopy in the Chinese-American Eye Study (CHES)

    PubMed Central

    Murakami, Yohko; Wang, Dandan; Burkemper, Bruce; Lin, Shan C.; Varma, Rohit

    2016-01-01

    Purpose To compare grading of goniophotographic images and gonioscopy in assessing the iridocorneal angle. Methods In a population-based, cross-sectional study, participants underwent gonioscopy and goniophotographic imaging during the same visit. The iridocorneal angle was classified as closed if the posterior trabecular meshwork could not be seen. A single masked observer graded the goniophotographic images, and each eye was classified as having angle closure based on the number of closed quadrants. Agreement between the methods was analyzed by calculating kappa (κ) and first-order agreement coefficient (AC1) statistics and comparison of area under receiver operating characteristic curves (AUC). Results A total of 4149 Chinese Americans (3994 eyes) were included in this study. The agreement for angle closure diagnosis between gonioscopy and EyeCam was moderate to excellent (κ = 0.60, AC1 0.90, AUC 0.76–0.80). Conclusions Detection of iridocorneal angle closure based on goniophotographic imaging shows moderate to very good agreement with angle closure assessment using gonioscopy. PMID:27571018

  13. Developmental validation of the HIrisPlex system: DNA-based eye and hair colour prediction for forensic and anthropological usage.

    PubMed

    Walsh, Susan; Chaitanya, Lakshmi; Clarisse, Lindy; Wirken, Laura; Draus-Barini, Jolanta; Kovatsi, Leda; Maeda, Hitoshi; Ishikawa, Takaki; Sijen, Titia; de Knijff, Peter; Branicki, Wojciech; Liu, Fan; Kayser, Manfred

    2014-03-01

    Forensic DNA Phenotyping or 'DNA intelligence' tools are expected to aid police investigations and find unknown individuals by providing information on externally visible characteristics of unknown suspects, perpetrators and missing persons from biological samples. This is especially useful in cases where conventional DNA profiling or other means remain non-informative. Recently, we introduced the HIrisPlex system, capable of predicting both eye and hair colour from DNA. In the present developmental validation study, we demonstrate that the HIrisPlex assay performs in full agreement with the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines providing an essential prerequisite for future HIrisPlex applications to forensic casework. The HIrisPlex assay produces complete profiles down to only 63 pg of DNA. Species testing revealed human specificity for a complete HIrisPlex profile, while only non-human primates showed the closest full profile at 20 out of the 24 DNA markers, in all animals tested. Rigorous testing of simulated forensic casework samples such as blood, semen, saliva stains, hairs with roots as well as extremely low quantity touch (trace) DNA samples, produced complete profiles in 88% of cases. Concordance testing performed between five independent forensic laboratories displayed consistent reproducible results on varying types of DNA samples. Due to its design, the assay caters for degraded samples, underlined here by results from artificially degraded DNA and from simulated casework samples of degraded DNA. This aspect was also demonstrated previously on DNA samples from human remains up to several hundreds of years old. With this paper, we also introduce enhanced eye and hair colour prediction models based on enlarged underlying databases of HIrisPlex genotypes and eye/hair colour phenotypes (eye colour: N = 9188 and hair colour: N = 1601). Furthermore, we present an online web-based system for individual eye and hair colour

  14. The Feasibility of Capturing Learner Interactions Based on Logs Informed by Eye-Tracking and Remote Observation Studies

    ERIC Educational Resources Information Center

    San Diego, Jonathan P.; McAndrew, Patrick

    2009-01-01

    Two small studies, one an "eye-tracking" study and the other a "remote observation" study, have been conducted to investigate ways to identify two kinds of online learner interactions: users flicking through the web pages in "browsing" action, and users engaging with the content of a page in "learning"…

  15. A software module for implementing auditory and visual feedback on a video-based eye tracking system

    NASA Astrophysics Data System (ADS)

    Rosanlall, Bharat; Gertner, Izidor; Geri, George A.; Arrington, Karl F.

    2016-05-01

    We describe here the design and implementation of a software module that provides both auditory and visual feedback of the eye position measured by a commercially available eye tracking system. The present audio-visual feedback module (AVFM) serves as an extension to the Arrington Research ViewPoint EyeTracker, but it can be easily modified for use with other similar systems. Two modes of audio feedback and one mode of visual feedback are provided in reference to a circular area-of-interest (AOI). Auditory feedback can be either a click tone emitted when the user's gaze point enters or leaves the AOI, or a sinusoidal waveform with frequency inversely proportional to the distance from the gaze point to the center of the AOI. Visual feedback is in the form of a small circular light patch that is presented whenever the gaze-point is within the AOI. The AVFM processes data that are sent to a dynamic-link library by the EyeTracker. The AVFM's multithreaded implementation also allows real-time data collection (1 kHz sampling rate) and graphics processing that allow display of the current/past gaze-points as well as the AOI. The feedback provided by the AVFM described here has applications in military target acquisition and personnel training, as well as in visual experimentation, clinical research, marketing research, and sports training.

  16. Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study

    PubMed Central

    Ravilla, Thulasiraj D.; Gupta, Sanjeev; Ravindran, Ravilla D.; Vashist, Praveen; Krishnan, Tiruvengada; Maraini, Giovanni; Chakravarthy, Usha; Fletcher, Astrid E.

    2016-01-01

    Background: Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited. Objectives: To examine the association of biomass cooking fuels with cataract and type of cataract. Methods: We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution. Results: Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men. Conclusions: Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857–1862; http://dx.doi.org/10.1289/EHP193 PMID:27227523

  17. In the eye of the beholder: a survey of models for eyes and gaze.

    PubMed

    Hansen, Dan Witzner; Ji, Qiang

    2010-03-01

    Despite active research and significant progress in the last 30 years, eye detection and tracking remains challenging due to the individuality of eyes, occlusion, variability in scale, location, and light conditions. Data on eye location and details of eye movements have numerous applications and are essential in face detection, biometric identification, and particular human-computer interaction tasks. This paper reviews current progress and state of the art in video-based eye detection and tracking in order to identify promising techniques as well as issues to be further addressed. We present a detailed review of recent eye models and techniques for eye detection and tracking. We also survey methods for gaze estimation and compare them based on their geometric properties and reported accuracies. This review shows that, despite their apparent simplicity, the development of a general eye detection technique involves addressing many challenges, requires further theoretical developments, and is consequently of interest to many other domains problems in computer vision and beyond.

  18. EEG Negativity in Fixations Used for Gaze-Based Control: Toward Converting Intentions into Actions with an Eye-Brain-Computer Interface.

    PubMed

    Shishkin, Sergei L; Nuzhdin, Yuri O; Svirin, Evgeny P; Trofimov, Alexander G; Fedorova, Anastasia A; Kozyrskiy, Bogdan L; Velichkovsky, Boris M

    2016-01-01

    We usually look at an object when we are going to manipulate it. Thus, eye tracking can be used to communicate intended actions. An effective human-machine interface, however, should be able to differentiate intentional and spontaneous eye movements. We report an electroencephalogram (EEG) marker that differentiates gaze fixations used for control from spontaneous fixations involved in visual exploration. Eight healthy participants played a game with their eye movements only. Their gaze-synchronized EEG data (fixation-related potentials, FRPs) were collected during game's control-on and control-off conditions. A slow negative wave with a maximum in the parietooccipital region was present in each participant's averaged FRPs in the control-on conditions and was absent or had much lower amplitude in the control-off condition. This wave was similar but not identical to stimulus-preceding negativity, a slow negative wave that can be observed during feedback expectation. Classification of intentional vs. spontaneous fixations was based on amplitude features from 13 EEG channels using 300 ms length segments free from electrooculogram contamination (200-500 ms relative to the fixation onset). For the first fixations in the fixation triplets required to make moves in the game, classified against control-off data, a committee of greedy classifiers provided 0.90 ± 0.07 specificity and 0.38 ± 0.14 sensitivity. Similar (slightly lower) results were obtained for the shrinkage Linear Discriminate Analysis (LDA) classifier. The second and third fixations in the triplets were classified at lower rate. We expect that, with improved feature sets and classifiers, a hybrid dwell-based Eye-Brain-Computer Interface (EBCI) can be built using the FRP difference between the intended and spontaneous fixations. If this direction of BCI development will be successful, such a multimodal interface may improve the fluency of interaction and can possibly become the basis for a new input device

  19. A questionnaire-based survey of dry eye disease among leather tannery workers in Kanpur, India: a case-control study.

    PubMed

    Gupta, Ramesh Chandra; Ranjan, Ratnesh; Kushwaha, Raj Nath; Khan, Perwez; Mohan, Shalini

    2014-12-01

    Kanpur is a major leather processing center in India, where a large number of tanneries are situated. During tanning process, workers are constantly exposed to heat, leather dust produced in buffering operations and a wide range of chemicals. All these factors are known to cause dry eye. Being ophthalmologists of a tertiary health care center in Kanpur, we used to notice over a period of time that a considerable number of patients with dry eye symptoms, attending our out-patient department, were related to leather tanning industries. But, no published data is available on the prevalence of and risk factors for dry eye disorders among tannery worker. To estimate the prevalence of dry eye problem and its severity among the workers of leather tanneries in the industrial belt of Kanpur and to evaluate various risk factors related to it. In this cross-sectional case-control study, Ocular Surface Disease Index (OSDI) Questionnaire was presented to randomly selected tannery workers and control group. OSDI score was calculated based on subjects' response, and was evaluated with OSDI chart to assess the magnitude of dry eye symptoms and to grade its severity. RESULTS were analyzed statistically to evaluate the significance level. A total of 800 workers were selected by simple random sampling, out of which 72 workers were excluded from the study. Thus the questionnaire was presented to a total of 728 workers, while control group included 260 individuals. All the workers as well as controls were male with age ranging from 20 to 59 years. The mean age for tannery workers was 34.05 ± 8.96 years and that for control group was 32.97 ± 10.59 years (p = 0.14). The tannery workers had mean duration of work at tanneries for 6.99 ± 4.86 years. The prevalence of dry eye symptoms among tannery workers was 33.79% (95% CI: 30.35-37.24), while that in control group was 15.77% (95% CI: 11.31-20.23) (p < 0.0001). Among symptomatic workers, 47.96% (95% CI: 41.68-54.26) workers had mild, 36

  20. Selective laser trabeculoplasty for early glaucoma: analysis of success predictors and adjusted laser outcomes based on the untreated fellow eye.

    PubMed

    Chun, Mikael; Gracitelli, Carolina P B; Lopes, Flavio S; Biteli, Luis G; Ushida, Michele; Prata, Tiago S

    2016-11-23

    To identify success predictors and to study the role of the fellow untreated eye as a co-variable for adjustment of intraocular pressure (IOP) outcomes following selective laser trabeculoplasty (SLT) in early open-angle glaucoma (OAG) patients. A case series was carried out. Patients with uncontrolled early OAG or ocular hypertension (inadequate IOP control requiring additional treatment) underwent SLT (one single laser session) performed by the same surgeon in a standardized fashion. The same preoperative medical regimen was maintained during follow-up for all patients. Post-treatment assessments were scheduled at week 1 and months 1, 2, and 3. In order to account for possible influence of IOP fluctuation on laser outcomes, post-laser IOP values of the treated eye of each patient were also analyzed adjusting for IOP changes (between visits variation) of the untreated fellow eye (adjusted analysis). Pre and post-laser IOP values were compared using paired t-test. Factors associated with the magnitude of IOP reduction were investigated using multiple regression analysis. A total of 45 eyes of 45 patients were enrolled. Mean IOP was reduced from 20.8 ± 5.1 to 14.9 ± 2.9 mmHg at month 3 (p < 0.001). Adjusted success rate (defined as IOP reduction ≥ 20%) was 64% and mean percentage of IOP reduction was 23.1 ± 14.3% at last follow-up visit. Considering unadjusted post-laser IOP values, it was found a 20% greater absolute IOP reduction (median [interquartile range] 6 mmHg [4-7] vs 5 mmHg [3-7]; p = 0.04), with a success rate of 76%. Although baseline IOP was significantly associated with both adjusted and unadjusted post-laser IOP reduction, a stronger association was found when unadjusted IOP values were considered (p < 0.001 and R (2) = 0.35; p < 0.001 and R (2) = 0.67, respectively). Age, mean deviation (MD) index, central corneal thickness and type of glaucoma were not significant predictors (p ≥ 0.150). In this

  1. Eating for Your Eyes

    ERIC Educational Resources Information Center

    Stastny, Sherri Nordstrom; Garden-Robinson, Julie

    2011-01-01

    An educational program targeting older adults was developed to increase knowledge regarding nutrition and eye health. With age, the chance for eye disease increases, so prevention is critical. The Eating for Your Eyes program has promoted behavior changes regarding eye health among the participants. This program is easily replicated and use is…

  2. Eating for Your Eyes

    ERIC Educational Resources Information Center

    Stastny, Sherri Nordstrom; Garden-Robinson, Julie

    2011-01-01

    An educational program targeting older adults was developed to increase knowledge regarding nutrition and eye health. With age, the chance for eye disease increases, so prevention is critical. The Eating for Your Eyes program has promoted behavior changes regarding eye health among the participants. This program is easily replicated and use is…

  3. Eye Injuries (For Parents)

    MedlinePlus

    ... the eye nausea or vomiting after an eye injury Think Prevention! Kids who play sports should wear protective goggles or unbreakable glasses as needed. Keep chemicals and other potentially dangerous objects out of the reach of children. Reviewed by: Steven Dowshen, ... (Conjunctivitis) Eyes Corneal Abrasions Styes Activity: Eyes ...

  4. Eye Injuries in Sports

    MedlinePlus

    ... and Fitness Sports Safety Eye Injuries in Sports Eye Injuries in Sports Exercise and FitnessPrevention and WellnessSports Safety Share Eye Injuries ... injury, detached retina, patient education, patient information, penetrating eye ... Exercise and Fitness, Prevention and Wellness, Sports Safety June ...

  5. Reconstruction of eye movements during blinks

    NASA Astrophysics Data System (ADS)

    Baptista, M. S.; Bohn, C.; Kliegl, R.; Engbert, R.; Kurths, J.

    2008-03-01

    In eye movement research in reading, the amount of data plays a crucial role for the validation of results. A methodological problem for the analysis of the eye movement in reading are blinks, when readers close their eyes. Blinking rate increases with increasing reading time, resulting in high data losses, especially for older adults or reading impaired subjects. We present a method, based on the symbolic sequence dynamics of the eye movements, that reconstructs the horizontal position of the eyes while the reader blinks. The method makes use of an observed fact that the movements of the eyes before closing or after opening contain information about the eyes movements during blinks. Test results indicate that our reconstruction method is superior to methods that use simpler interpolation approaches. In addition, analyses of the reconstructed data show no significant deviation from the usual behavior observed in readers.

  6. Choroidal vascularity index as a measure of vascular status of the choroid: Measurements in healthy eyes from a population-based study.

    PubMed

    Agrawal, Rupesh; Gupta, Preeti; Tan, Kara-Anne; Cheung, Chui Ming Gemmy; Wong, Tien-Yin; Cheng, Ching-Yu

    2016-02-12

    The vascularity of the choroid has been implicated in the pathogenesis of various eye diseases. To date, no established quantifiable parameters to estimate vascular status of the choroid exists. Choroidal vascularity index (CVI) may potentially be used to assess vascular status of the choroid. We aimed to establish normative database for CVI and identify factors associated with CVI in healthy eyes. In this population-based study on 345 healthy eyes, choroidal enhanced depth imaging optical coherence tomography scans were segmented by modified image binarization technique. Total subfoveal choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area. CVI was calculated as the proportion of LA to TCA. Linear regression was used to identify ocular and systemic factors associated with CVI and subfoveal choroidal thickness (SFCT). Subfoveal CVI ranged from 60.07 to 71.27% with a mean value of 65.61 ± 2.33%. CVI was less variable than SFCT (coefficient of variation for CVI was 3.55 vs 40.30 for SFCT). Higher CVI was associated with thicker SFCT, but not associated with most physiological variables. CVI was elucidated as a significant determinant of SFCT. While SFCT was affected by many factors, CVI remained unaffected suggesting CVI to be a more robust marker of choroidal diseases.

  7. Choroidal vascularity index as a measure of vascular status of the choroid: Measurements in healthy eyes from a population-based study

    PubMed Central

    Agrawal, Rupesh; Gupta, Preeti; Tan, Kara-Anne; Cheung, Chui Ming Gemmy; Wong, Tien-Yin; Cheng, Ching-Yu

    2016-01-01

    The vascularity of the choroid has been implicated in the pathogenesis of various eye diseases. To date, no established quantifiable parameters to estimate vascular status of the choroid exists. Choroidal vascularity index (CVI) may potentially be used to assess vascular status of the choroid. We aimed to establish normative database for CVI and identify factors associated with CVI in healthy eyes. In this population-based study on 345 healthy eyes, choroidal enhanced depth imaging optical coherence tomography scans were segmented by modified image binarization technique. Total subfoveal choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area. CVI was calculated as the proportion of LA to TCA. Linear regression was used to identify ocular and systemic factors associated with CVI and subfoveal choroidal thickness (SFCT). Subfoveal CVI ranged from 60.07 to 71.27% with a mean value of 65.61 ± 2.33%. CVI was less variable than SFCT (coefficient of variation for CVI was 3.55 vs 40.30 for SFCT). Higher CVI was associated with thicker SFCT, but not associated with most physiological variables. CVI was elucidated as a significant determinant of SFCT. While SFCT was affected by many factors, CVI remained unaffected suggesting CVI to be a more robust marker of choroidal diseases. PMID:26868048

  8. Choroidal vascularity index as a measure of vascular status of the choroid: Measurements in healthy eyes from a population-based study

    NASA Astrophysics Data System (ADS)

    Agrawal, Rupesh; Gupta, Preeti; Tan, Kara-Anne; Cheung, Chui Ming Gemmy; Wong, Tien-Yin; Cheng, Ching-Yu

    2016-02-01

    The vascularity of the choroid has been implicated in the pathogenesis of various eye diseases. To date, no established quantifiable parameters to estimate vascular status of the choroid exists. Choroidal vascularity index (CVI) may potentially be used to assess vascular status of the choroid. We aimed to establish normative database for CVI and identify factors associated with CVI in healthy eyes. In this population-based study on 345 healthy eyes, choroidal enhanced depth imaging optical coherence tomography scans were segmented by modified image binarization technique. Total subfoveal choroidal area (TCA) was segmented into luminal (LA) and stromal (SA) area. CVI was calculated as the proportion of LA to TCA. Linear regression was used to identify ocular and systemic factors associated with CVI and subfoveal choroidal thickness (SFCT). Subfoveal CVI ranged from 60.07 to 71.27% with a mean value of 65.61 ± 2.33%. CVI was less variable than SFCT (coefficient of variation for CVI was 3.55 vs 40.30 for SFCT). Higher CVI was associated with thicker SFCT, but not associated with most physiological variables. CVI was elucidated as a significant determinant of SFCT. While SFCT was affected by many factors, CVI remained unaffected suggesting CVI to be a more robust marker of choroidal diseases.

  9. Juvenile eye growth, when completed? An evaluation based on IOL-Master axial length data, cross-sectional and longitudinal.

    PubMed

    Fledelius, Hans C; Christensen, Anders S; Fledelius, Christian

    2014-05-01

    To test Sorsby's classical statement of axial eye growth as completed at the age of 13 years, with a view also to differentiating between basic eye growth and juvenile elongation associated with eventual refractive change towards myopia. (i) A total of 160 healthy eyes close to emmetropia were included in a cross-sectional set-up (age 4-20 years, 91 males, 69 females), and (ii) 78 longitudinal data sets (67 male and 11 female annual repeat exams over 2-7 years, n=30; age span 4-19 years) were available for evaluating individual axial elongation. The IOL-Master equipment was preferred for conventional ultrasound oculometry due to its extreme repeatability of measuring values, thus making it well fitted for evaluating very small differences. In particular, this had bearing for the decelerating end phase of growth in the longitudinal investigation. Sorby's statement about age 13 as general limit found support from the cross-sectional data, which suggested stable emmetropic eye size from about 11-12 years, with an average apparently outgrown male emmetropic value of 23.5 mm versus females' 22.9 mm. The longitudinal data, however, showed emmetropic growth also beyond this age, with individual data to establish continued axial elongation also at age 13-18 years. The final basic teenage growth is however minute and without practical implications. Individual ocular growth curves have indicated axial elongation to occur also after the age of 13 years. With regard to the - mainly academic - discrepancy between cross-sectional and longitudinal results, bigger samples are needed, and the juvenile myopic trend has to be acknowledged. © 2013 The Authors. Acta Ophthalmologica © 2013 Acta Ophthalmologica Scandinavica Foundation. Published by Blackwell Publishing Ltd.

  10. Naked-eye and Selective Detection of Mercury (II) Ions in Mixed Aqueous Media Using a Cellulose-based Support

    PubMed Central

    Díez-Gil, César; Caballero, Antonio; Ratera, Imma; Tárraga, Alberto; Molina, Pedro; Veciana, Jaume

    2007-01-01

    A test paper for high-selectivity detecting Hg2+ ions in mixed acetonitrile-water solutions has been achieved using a bis(ferrocenyl) azine, as chromogenic chemosensor molecule, and a solid cellulose fibre, as a substrate. Depending on the amount of mercury ions in contact with the detecting molecule a spectacular color change in the cellulose indicator is produced, being possible to determine the concentration of Hg2+ ions either by naked eye or spectroscopically.

  11. Volitional and Real-Time Control Cursor Based on Eye Movement Decoding Using a Linear Decoding Model

    PubMed Central

    Zhang, Cheng

    2016-01-01

    The aim of this study is to build a linear decoding model that reveals the relationship between the movement information and the EOG (electrooculogram) data to online control a cursor continuously with blinks and eye pursuit movements. First of all, a blink detection method is proposed to reject a voluntary single eye blink or double-blink information from EOG. Then, a linear decoding model of time series is developed to predict the position of gaze, and the model parameters are calibrated by the RLS (Recursive Least Square) algorithm; besides, the assessment of decoding accuracy is assessed through cross-validation procedure. Additionally, the subsection processing, increment control, and online calibration are presented to realize the online control. Finally, the technology is applied to the volitional and online control of a cursor to hit the multiple predefined targets. Experimental results show that the blink detection algorithm performs well with the voluntary blink detection rate over 95%. Through combining the merits of blinks and smooth pursuit movements, the movement information of eyes can be decoded in good conformity with the average Pearson correlation coefficient which is up to 0.9592, and all signal-to-noise ratios are greater than 0. The novel system allows people to successfully and economically control a cursor online with a hit rate of 98%. PMID:28058044

  12. Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement.

    PubMed

    Penna, Rachele R; de Sanctis, Ugo; Catalano, Martina; Brusasco, Luca; Grignolo, Federico M

    2017-01-01

    To compare the repeatability/reproducibility of measurement by high-resolution Placido disk-based topography with that of a high-resolution rotating Scheimpflug camera and assess the agreement between the two instruments in measuring corneal power in eyes with keratoconus and post-laser in situ keratomileusis (LASIK). One eye each of 36 keratoconic patients and 20 subjects who had undergone LASIK was included in this prospective observational study. Two independent examiners worked in a random order to take three measurements of each eye with both instruments. Four parameters were measured on the anterior cornea: steep keratometry (Ks), flat keratometry (Kf), mean keratometry (Km), and astigmatism (Ks-Kf). Intra-examiner repeatability and inter-examiner reproducibility were evaluated by calculating the within-subject standard deviation (Sw) the coefficient of repeatability (R), the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC). Agreement between instruments was tested with the Bland-Altman method by calculating the 95% limits of agreement (95% LoA). In keratoconic eyes, the intra-examiner and inter-examiner ICC were >0.95. As compared with measurement by high-resolution Placido disk-based topography, the intra-examiner R of the high-resolution rotating Scheimpflug camera was lower for Kf (0.32 vs 0.88), Ks (0.61 vs 0.88), and Km (0.32 vs 0.84) but higher for Ks-Kf (0.70 vs 0.57). Inter-examiner R values were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The 95% LoA were -1.28 to +0.55 for Kf, -1.36 to +0.99 for Ks, -1.08 to +0.50 for Km, and -1.11 to +1.48 for Ks-Kf. In the post-LASIK eyes, the intra-examiner and inter-examiner ICC were >0.87 for all parameters. The intra-examiner and inter-examiner R were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The intra-examiner R was 0.17 vs 0.88 for Kf, 0.21 vs 0.88 for Ks, 0.17 vs 0.86 for Km, and 0

  13. Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement

    PubMed Central

    Penna, Rachele R.; de Sanctis, Ugo; Catalano, Martina; Brusasco, Luca; Grignolo, Federico M.

    2017-01-01

    AIM To compare the repeatability/reproducibility of measurement by high-resolution Placido disk-based topography with that of a high-resolution rotating Scheimpflug camera and assess the agreement between the two instruments in measuring corneal power in eyes with keratoconus and post-laser in situ keratomileusis (LASIK). METHODS One eye each of 36 keratoconic patients and 20 subjects who had undergone LASIK was included in this prospective observational study. Two independent examiners worked in a random order to take three measurements of each eye with both instruments. Four parameters were measured on the anterior cornea: steep keratometry (Ks), flat keratometry (Kf), mean keratometry (Km), and astigmatism (Ks-Kf). Intra-examiner repeatability and inter-examiner reproducibility were evaluated by calculating the within-subject standard deviation (Sw) the coefficient of repeatability (R), the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC). Agreement between instruments was tested with the Bland-Altman method by calculating the 95% limits of agreement (95% LoA). RESULTS In keratoconic eyes, the intra-examiner and inter-examiner ICC were >0.95. As compared with measurement by high-resolution Placido disk-based topography, the intra-examiner R of the high-resolution rotating Scheimpflug camera was lower for Kf (0.32 vs 0.88), Ks (0.61 vs 0.88), and Km (0.32 vs 0.84) but higher for Ks-Kf (0.70 vs 0.57). Inter-examiner R values were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The 95% LoA were -1.28 to +0.55 for Kf, -1.36 to +0.99 for Ks, -1.08 to +0.50 for Km, and -1.11 to +1.48 for Ks-Kf. In the post-LASIK eyes, the intra-examiner and inter-examiner ICC were >0.87 for all parameters. The intra-examiner and inter-examiner R were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The intra-examiner R was 0.17 vs 0.88 for Kf, 0.21 vs 0.88 for Ks, 0.17 vs 0

  14. Novel automatic eye detection and tracking algorithm

    NASA Astrophysics Data System (ADS)

    Ghazali, Kamarul Hawari; Jadin, Mohd Shawal; Jie, Ma; Xiao, Rui

    2015-04-01

    The eye is not only one of the most complex but also the most important sensory organ of the human body. Eye detection and eye tracking are basement and hot issue in image processing. A non-invasive eye location and eye tracking is promising for hands-off gaze-based human-computer interface, fatigue detection, instrument control by paraplegic patients and so on. For this purpose, an innovation work frame is proposed to detect and tracking eye in video sequence in this paper. The contributions of this work can be divided into two parts. The first contribution is that eye filters were trained which can detect eye location efficiently and accurately without constraints on the background and skin colour. The second contribution is that a framework of tracker based on sparse representation and LK optic tracker were built which can track eye without constraint on eye status. The experimental results demonstrate the accuracy aspects and the real-time applicability of the proposed approach.

  15. Carotenoid-based bill and eye ring coloration as honest signals of condition: an experimental test in the red-legged partridge (Alectoris rufa).

    PubMed

    Pérez-Rodríguez, Lorenzo; Viñuela, Javier

    2008-09-01

    Carotenoid pigments cannot be synthesized by vertebrates but must be ingested through the diet. As they seem to be a limited resource, carotenoid-based ornaments are particularly interesting as possible honest signals of individual quality, in particular of foraging efficiency and nutritional status. Some studies have demonstrated the condition dependence of carotenoid-based plumage in birds. However, many other carotenoid-pigmented bare parts (i.e. skin, caruncles, bills, cere, and tarsi) are present in birds but, in comparison with plumage, little is known about these traits as indicators of individual quality. Here, we show that the eye ring pigmentation and bill redness of the red-legged partridge (Alectoris rufa) are positively associated to body condition and recent changes in body mass. Also, we found a negative relationship between these two traits and heterophil-to-lymphocyte ratio, an indicator of physiological stress (the relationship with bill redness being significant only for males). In an experiment, we found that after a period of reduction in food intake (with the consequent loss of body mass), food-restricted birds showed lower eye ring pigmentation than ad-libitum-fed birds. Therefore, different ornaments seem to reflect changes in body condition but at different speeds or intensities (eye ring, a fleshy ornament, appears to respond more rapidly to changes in the nutritional status than a keratinized structure as the bill). These results indicate that carotenoid-based ornaments are condition-dependent traits in the red-legged partridge, being therefore susceptible to be employed as honest signals of quality in sexual selection.

  16. Carotenoid-based bill and eye ring coloration as honest signals of condition: an experimental test in the red-legged partridge ( Alectoris rufa)

    NASA Astrophysics Data System (ADS)

    Pérez-Rodríguez, Lorenzo; Viñuela, Javier

    2008-09-01

    Carotenoid pigments cannot be synthesized by vertebrates but must be ingested through the diet. As they seem to be a limited resource, carotenoid-based ornaments are particularly interesting as possible honest signals of individual quality, in particular of foraging efficiency and nutritional status. Some studies have demonstrated the condition dependence of carotenoid-based plumage in birds. However, many other carotenoid-pigmented bare parts (i.e. skin, caruncles, bills, cere, and tarsi) are present in birds but, in comparison with plumage, little is known about these traits as indicators of individual quality. Here, we show that the eye ring pigmentation and bill redness of the red-legged partridge ( Alectoris rufa) are positively associated to body condition and recent changes in body mass. Also, we found a negative relationship between these two traits and heterophil-to-lymphocyte ratio, an indicator of physiological stress (the relationship with bill redness being significant only for males). In an experiment, we found that after a period of reduction in food intake (with the consequent loss of body mass), food-restricted birds showed lower eye ring pigmentation than ad-libitum-fed birds. Therefore, different ornaments seem to reflect changes in body condition but at different speeds or intensities (eye ring, a fleshy ornament, appears to respond more rapidly to changes in the nutritional status than a keratinized structure as the bill). These results indicate that carotenoid-based ornaments are condition-dependent traits in the red-legged partridge, being therefore susceptible to be employed as honest signals of quality in sexual selection.

  17. Factors Associated with Awareness, Attitudes and Practices Regarding Common Eye Diseases in the General Population in a Rural District in Bangladesh: The Bangladesh Population-based Diabetes and Eye Study (BPDES).

    PubMed

    Islam, Fakir M Amirul; Chakrabarti, Rahul; Islam, Silvia Z; Finger, Robert P; Critchley, Christine

    2015-01-01

    To assess the awareness, attitudes, and practices associated with common eye diseases and eye care utilization in a rural district of Bangladesh. Data were collected using a multilevel cluster random sampling technique from 3104 adults aged ≥30 years from the Banshgram union with a questionnaire assessing the awareness, attitudes and practice about diabetes and common eye diseases, educational attainment, socio-economic status, and medical history. Participants were aged between 30 and 89 years with a mean (SD) age of 51 (12) years and 65% were female. The majority of participants had heard of cataracts (90%), trachoma (86%) and Pterygium (84%), yet only 4% had heard of diabetic retinopathy (DR), 7% of glaucoma and 8% of Age-related macular degeneration (AMD). However, 58% of participants did not know vision loss could be prevented. Factors associated with lower awareness regarding common eye diseases were increasing age, lack of formal schooling, and lower socio-economic status. A lower proportion (57%) of people with no schooling compared to those who had attained at least secondary school certificate education (72%) reported that they knew that vision loss could be prevented (p<0.001). Overall 51% of people had heard of at least six (67%) out of nine items relating to awareness of common eye diseases. This included 41% of participants aged 65 years or older compared to 61% of those aged 30-35 years (p<0.001). Only 4% had an eye check at least once a year and higher education and better SES were associated with higher frequency of eye checks. In rural Bangladesh awareness of cataract, trachoma and pterygium was good but limited in relation to the potentially blinding conditions of glaucoma, DR, and AMD. The results show a large gap between public awareness and treatment practices about common eye diseases. Public health promotion should be designed to address these knowledge gaps.

  18. Factors Associated with Awareness, Attitudes and Practices Regarding Common Eye Diseases in the General Population in a Rural District in Bangladesh: The Bangladesh Population-based Diabetes and Eye Study (BPDES)

    PubMed Central

    Islam, Fakir M. Amirul; Chakrabarti, Rahul; Islam, Silvia Z.; Finger, Robert P.; Critchley, Christine

    2015-01-01

    Background To assess the awareness, attitudes, and practices associated with common eye diseases and eye care utilization in a rural district of Bangladesh. Methods Data were collected using a multilevel cluster random sampling technique from 3104 adults aged ≥30 years from the Banshgram union with a questionnaire assessing the awareness, attitudes and practice about diabetes and common eye diseases, educational attainment, socio-economic status, and medical history. Results Participants were aged between 30 and 89 years with a mean (SD) age of 51 (12) years and 65% were female. The majority of participants had heard of cataracts (90%), trachoma (86%) and Pterygium (84%), yet only 4% had heard of diabetic retinopathy (DR), 7% of glaucoma and 8% of Age-related macular degeneration (AMD). However, 58% of participants did not know vision loss could be prevented. Factors associated with lower awareness regarding common eye diseases were increasing age, lack of formal schooling, and lower socio-economic status. A lower proportion (57%) of people with no schooling compared to those who had attained at least secondary school certificate education (72%) reported that they knew that vision loss could be prevented (p<0.001). Overall 51% of people had heard of at least six (67%) out of nine items relating to awareness of common eye diseases. This included 41% of participants aged 65 years or older compared to 61% of those aged 30–35 years (p<0.001). Only 4% had an eye check at least once a year and higher education and better SES were associated with higher frequency of eye checks. Conclusions In rural Bangladesh awareness of cataract, trachoma and pterygium was good but limited in relation to the potentially blinding conditions of glaucoma, DR, and AMD. The results show a large gap between public awareness and treatment practices about common eye diseases. Public health promotion should be designed to address these knowledge gaps. PMID:26200458

  19. Functional eye movement disorders.

    PubMed

    Kaski, D; Bronstein, A M

    2017-01-01

    Functional (psychogenic) eye movement disorders are perhaps less established in the medical literature than other types of functional movement disorders. Patients may present with ocular symptoms (e.g., blurred vision or oscillopsia) or functional eye movements may be identified during the formal examination of the eyes in patients with other functional disorders. Convergence spasm is the most common functional eye movement disorder, but functional gaze limitation, functional eye oscillations (also termed "voluntary nystagmus"), and functional convergence paralysis may be underreported. This chapter reviews the different types of functional eye movement abnormalities and provides a practical framework for their diagnosis and management.

  20. Lens of Eye Dosimetry

    SciTech Connect

    Mallett, Michael Wesley

    2015-03-23

    An analysis of LANL occupational dose measurements was made with respect to lens of eye dose (LOE), in particular, for plutonium workers. Table 1 shows the reported LOE as a ratio of the “deep” (photon only) and “deep+neutron” dose for routine monitored workers at LANL for the past ten years. The data compares the mean and range of these values for plutonium workers* and non-routine plutonium workers. All doses were reported based on measurements with the LANL Model 8823 TLD.

  1. Eye muscle test (image)

    MedlinePlus

    ... the extraocular muscles which results in uncontrolled eye movements. The test involves moving the eyes in six different directions in space to evaluate the proper functioning of the extraocular ...

  2. Eye Drop Tips

    MedlinePlus

    ... Involved News About Us Donate In This Section Eye Drop Tips en Español email Send this article ... the reach of children. Steps For Putting In Eye Drops: Start by tilting your head backward while ...

  3. Diabetic Eye Problems

    MedlinePlus

    ... too high. Over time, this can damage your eyes. The most common problem is diabetic retinopathy. It ... light-sensitive tissue at the back of your eye. You need a healthy retina to see clearly. ...

  4. Eye Injuries (For Parents)

    MedlinePlus

    ... and comfortable as possible until help arrives. continue Chemical Exposure Many chemicals, even those found around the house, can damage an eye. If your child gets a chemical in the eye and you know what it ...

  5. Recommended Sports Eye Protectors

    MedlinePlus

    ... Eye Emergencies How to Jump Start a Car Battery Safely Electronic Screens and Your Eyes Nutrition and ... External Resources The Cost of Vision Problems The Future of Vision Vision Problems in the U.S. Healthy ...

  6. LASIK Eye Surgery

    MedlinePlus

    ... conditions. These conditions include: Autoimmune disorders, such as rheumatoid arthritis Immunodeficiency conditions caused by immunosuppressive medications or HIV Persistent dry eyes Unstable vision due to medications, hormonal changes, pregnancy, breast-feeding or age Several eye conditions, such ...

  7. Diabetes and eye disease

    MedlinePlus

    ... have damage to the blood vessels in your eye, some types of exercise can make the problem worse. Check with your health care provider before starting an exercise program. Other eye problems that can occur in people with diabetes ...

  8. Using the Mean Shift Algorithm to Make Post Hoc Improvements to the Accuracy of Eye Tracking Data Based on Probable Fixation Locations

    DTIC Science & Technology

    2010-08-01

    are from a test of the Tobii T60 eye tracker, which has a reported accuracy of 0.5º of visual angle and is widely used in usability studies. In...eye movement data generated by the E- Prime Tobii extension. VizFix can be used to define AOIs and generate a range of statistics from eye movement

  9. EEG Negativity in Fixations Used for Gaze-Based Control: Toward Converting Intentions into Actions with an Eye-Brain-Computer Interface

    PubMed Central

    Shishkin, Sergei L.; Nuzhdin, Yuri O.; Svirin, Evgeny P.; Trofimov, Alexander G.; Fedorova, Anastasia A.; Kozyrskiy, Bogdan L.; Velichkovsky, Boris M.

    2016-01-01

    We usually look at an object when we are going to manipulate it. Thus, eye tracking can be used to communicate intended actions. An effective human-machine interface, however, should be able to differentiate intentional and spontaneous eye movements. We report an electroencephalogram (EEG) marker that differentiates gaze fixations used for control from spontaneous fixations involved in visual exploration. Eight healthy participants played a game with their eye movements only. Their gaze-synchronized EEG data (fixation-related potentials, FRPs) were collected during game's control-on and control-off conditions. A slow negative wave with a maximum in the parietooccipital region was present in each participant's averaged FRPs in the control-on conditions and was absent or had much lower amplitude in the control-off condition. This wave was similar but not identical to stimulus-preceding negativity, a slow negative wave that can be observed during feedback expectation. Classification of intentional vs. spontaneous fixations was based on amplitude features from 13 EEG channels using 300 ms length segments free from electrooculogram contamination (200–500 ms relative to the fixation onset). For the first fixations in the fixation triplets required to make moves in the game, classified against control-off data, a committee of greedy classifiers provided 0.90 ± 0.07 specificity and 0.38 ± 0.14 sensitivity. Similar (slightly lower) results were obtained for the shrinkage Linear Discriminate Analysis (LDA) classifier. The second and third fixations in the triplets were classified at lower rate. We expect that, with improved feature sets and classifiers, a hybrid dwell-based Eye-Brain-Computer Interface (EBCI) can be built using the FRP difference between the intended and spontaneous fixations. If this direction of BCI development will be successful, such a multimodal interface may improve the fluency of interaction and can possibly become the basis for a new input device

  10. Panel-based Genetic Diagnostic Testing for Inherited Eye Diseases is Highly Accurate and Reproducible and More Sensitive for Variant Detection Than Exome Sequencing

    PubMed Central

    Bujakowska, Kinga M.; Sousa, Maria E.; Fonseca-Kelly, Zoë D.; Taub, Daniel G.; Janessian, Maria; Wang, Dan Yi; Au, Elizabeth D.; Sims, Katherine B.; Sweetser, David A.; Fulton, Anne B.; Liu, Qin; Wiggs, Janey L.; Gai, Xiaowu; Pierce, Eric A.

    2015-01-01

    Purpose Next-generation sequencing (NGS) based methods are being adopted broadly for genetic diagnostic testing, but the performance characteristics of these techniques have not been fully defined with regard to test accuracy and reproducibility. Methods We developed a targeted enrichment and NGS approach for genetic diagnostic testing of patients with inherited eye disorders, including inherited retinal degenerations, optic atrophy and glaucoma. In preparation for providing this Genetic Eye Disease (GEDi) test on a CLIA-certified basis, we performed experiments to measure the sensitivity, specificity, reproducibility as well as the clinical sensitivity of the test. Results The GEDi test is highly reproducible and accurate, with sensitivity and specificity for single nucleotide variant detection of 97.9% and 100%, respectively. The sensitivity for variant detection was notably better than the 88.3% achieved by whole exome sequencing (WES) using the same metrics, due to better coverage of targeted genes in the GEDi test compared to commercially available exome capture sets. Prospective testing of 192 patients with IRDs indicated that the clinical sensitivity of the GEDi test is high, with a diagnostic rate of 51%. Conclusion The data suggest that based on quantified performance metrics, selective targeted enrichment is preferable to WES for genetic diagnostic testing. PMID:25412400

  11. Persistence of Escherichia coli, Salmonella choleraesuis, Aujeszky's Disease virus and Blue Eye Disease virus in ensilages based on the solid fraction of pig faeces.

    PubMed

    Martínez-Gamba, R; Pradal-Roa, P; Castrejón, F P; Herradora, M; Galván, E; Mercado, C

    2001-10-01

    This study was carried out to determine the survival time of Escherichia coli, Salmonella choleraesuis, Aujeszky's Disease virus and Blue Eye Disease virus in ensilages based on the solid fraction of pig faeces. The four micro-organisms were inoculated into microsilos based on the solid fraction of pig faeces, sorghum and molasses. They were left for 0, 7, 14, 28 and 56 days, after which the state of each microsilo was evaluated, and isolation of the inoculated agents was attempted. The four inoculated agents were isolated only on day 0 of ensilage. The viral agents were identified through the cytopathic effect and fluorescence. It is concluded that ensilages based on the solid fraction of pig faeces appear to reduce the risk of the transmission of the agents inoculated in this study and help to reduce the environmental impact by using the solid in animal feed.

  12. Eye drop neurology.

    PubMed

    Bennetto, Luke; Guly, Catherine; Ormerod, Ian; Plant, Gordon T

    2014-06-01

    Eye drops can help to diagnose and prevent complications of neurological disorders. Guttae ophthalmicae (eye drops) are generally safe because the drugs rarely achieve significant systemic concentrations, although there are rare exceptions. This article covers contemporary pharmacological pupil testing; how to dilate a pupil safely; common reasons why pupils do not respond to drops; and corneal lubrication to prevent complications of weak eye closure.

  13. Eye Movements and Learning.

    ERIC Educational Resources Information Center

    Nesbit, Larry L.

    Research on the use of eye movement indices (such as number of fixations, the average fixation duration, and saccadic movements) as a measure of cognitive processing is reviewed in this paper. Information is provided on the physiology of the eye, computer applications to eye movement study, the influence of stimulus materials and intelligence on…

  14. Fish eye optics

    NASA Astrophysics Data System (ADS)

    Hudec, R.; Michalova, S.

    2017-07-01

    We report on small student (high—school) project of the Czech Academy of Sciences dealing with animal (fish) eyes and possible application in science and technology. Albeit most fishes have refractive eyes, the recent discoveries confirm that some fishes have reflective eyes with strange arrangements as well.

  15. Dwarf Eye Disorder

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Johns Hopkins researchers at the Wilmer Eye Institute have discovered what appears to be the first human gene mutation that causes extreme farsightedness. The researchers report that nanophthalmos, Greek for "dwarf eye," is a rare, potentially blinding disorder caused by an alteration in a gene called MFRP that helps control eye growth and…

  16. Dwarf Eye Disorder

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Johns Hopkins researchers at the Wilmer Eye Institute have discovered what appears to be the first human gene mutation that causes extreme farsightedness. The researchers report that nanophthalmos, Greek for "dwarf eye," is a rare, potentially blinding disorder caused by an alteration in a gene called MFRP that helps control eye growth and…

  17. Eye Movements and Learning.

    ERIC Educational Resources Information Center

    Nesbit, Larry L.

    Research on the use of eye movement indices (such as number of fixations, the average fixation duration, and saccadic movements) as a measure of cognitive processing is reviewed in this paper. Information is provided on the physiology of the eye, computer applications to eye movement study, the influence of stimulus materials and intelligence on…

  18. Automatic emotional expression analysis from eye area

    NASA Astrophysics Data System (ADS)

    Akkoç, Betül; Arslan, Ahmet

    2015-02-01

    Eyes play an important role in expressing emotions in nonverbal communication. In the present study, emotional expression classification was performed based on the features that were automatically extracted from the eye area. Fırst, the face area and the eye area were automatically extracted from the captured image. Afterwards, the parameters to be used for the analysis through discrete wavelet transformation were obtained from the eye area. Using these parameters, emotional expression analysis was performed through artificial intelligence techniques. As the result of the experimental studies, 6 universal emotions consisting of expressions of happiness, sadness, surprise, disgust, anger and fear were classified at a success rate of 84% using artificial neural networks.

  19. [Eye care management in Russian Federation].

    PubMed

    Neroev, V V

    2014-01-01

    The article presents an analysis of Russian eye care performance indicators based on federal and sector statistics over the recent years provided by the Ministry of Health of the Russian Federation, that is the incidence of eye diseases, eye care equipment provision, inpatient and outpatient volumes. Legal acts of the Russian Federation on health system in general and eye care in particular were taken into consideration when preparing the section on organizational matters. Problems of human resources, efficiency of specialists' time management, hospital beds use, and administrative issues in particular regions and Russia as a whole are discussed.

  20. Lowered threshold energy for femtosecond laser induced optical breakdown in a water based eye model by aberration correction with adaptive optics

    PubMed Central

    Hansen, Anja; Géneaux, Romain; Günther, Axel; Krüger, Alexander; Ripken, Tammo

    2013-01-01

    In femtosecond laser ophthalmic surgery tissue dissection is achieved by photodisruption based on laser induced optical breakdown. In order to minimize collateral damage to the eye laser surgery systems should be optimized towards the lowest possible energy threshold for photodisruption. However, optical aberrations of the eye and the laser system distort the irradiance distribution from an ideal profile which causes a rise in breakdown threshold energy even if great care is taken to minimize the aberrations of the system during design and alignment. In this study we used a water chamber with an achromatic focusing lens and a scattering sample as eye model and determined breakdown threshold in single pulse plasma transmission loss measurements. Due to aberrations, the precise lower limit for breakdown threshold irradiance in water is still unknown. Here we show that the threshold energy can be substantially reduced when using adaptive optics to improve the irradiance distribution by spatial beam shaping. We found that for initial aberrations with a root-mean-square wave front error of only one third of the wavelength the threshold energy can still be reduced by a factor of three if the aberrations are corrected to the diffraction limit by adaptive optics. The transmitted pulse energy is reduced by 17% at twice the threshold. Furthermore, the gas bubble motions after breakdown for pulse trains at 5 kilohertz repetition rate show a more transverse direction in the corrected case compared to the more spherical distribution without correction. Our results demonstrate how both applied and transmitted pulse energy could be reduced during ophthalmic surgery when correcting for aberrations. As a consequence, the risk of retinal damage by transmitted energy and the extent of collateral damage to the focal volume could be minimized accordingly when using adaptive optics in fs-laser surgery. PMID:23761849

  1. Lowered threshold energy for femtosecond laser induced optical breakdown in a water based eye model by aberration correction with adaptive optics.

    PubMed

    Hansen, Anja; Géneaux, Romain; Günther, Axel; Krüger, Alexander; Ripken, Tammo

    2013-06-01

    In femtosecond laser ophthalmic surgery tissue dissection is achieved by photodisruption based on laser induced optical breakdown. In order to minimize collateral damage to the eye laser surgery systems should be optimized towards the lowest possible energy threshold for photodisruption. However, optical aberrations of the eye and the laser system distort the irradiance distribution from an ideal profile which causes a rise in breakdown threshold energy even if great care is taken to minimize the aberrations of the system during design and alignment. In this study we used a water chamber with an achromatic focusing lens and a scattering sample as eye model and determined breakdown threshold in single pulse plasma transmission loss measurements. Due to aberrations, the precise lower limit for breakdown threshold irradiance in water is still unknown. Here we show that the threshold energy can be substantially reduced when using adaptive optics to improve the irradiance distribution by spatial beam shaping. We found that for initial aberrations with a root-mean-square wave front error of only one third of the wavelength the threshold energy can still be reduced by a factor of three if the aberrations are corrected to the diffraction limit by adaptive optics. The transmitted pulse energy is reduced by 17% at twice the threshold. Furthermore, the gas bubble motions after breakdown for pulse trains at 5 kilohertz repetition rate show a more transverse direction in the corrected case compared to the more spherical distribution without correction. Our results demonstrate how both applied and transmitted pulse energy could be reduced during ophthalmic surgery when correcting for aberrations. As a consequence, the risk of retinal damage by transmitted energy and the extent of collateral damage to the focal volume could be minimized accordingly when using adaptive optics in fs-laser surgery.

  2. A simple algorithm for distance estimation without radar and stereo vision based on the bionic principle of bee eyes

    NASA Astrophysics Data System (ADS)

    Khamukhin, A. A.

    2017-02-01

    Simple navigation algorithms are needed for small autonomous unmanned aerial vehicles (UAVs). These algorithms can be implemented in a small microprocessor with low power consumption. This will help to reduce the weight of the UAVs computing equipment and to increase the flight range. The proposed algorithm uses only the number of opaque channels (ommatidia in bees) through which a target can be seen by moving an observer from location 1 to 2 toward the target. The distance estimation is given relative to the distance between locations 1 and 2. The simple scheme of an appositional compound eye to develop calculation formula is proposed. The distance estimation error analysis shows that it decreases with an increase of the total number of opaque channels to a certain limit. An acceptable error of about 2 % is achieved with the angle of view from 3 to 10° when the total number of opaque channels is 21600.

  3. One-step detection of pathogens and cancer biomarkers by the naked eye based on aggregation of immunomagnetic beads

    NASA Astrophysics Data System (ADS)

    Chen, Yiping; Xianyu, Yunlei; Sun, Jiashu; Niu, Yajing; Wang, Yu; Jiang, Xingyu

    2015-12-01

    This report shows that immunomagnetic beads (IMBs) can act as the optical readout for assays, in addition to serving as the carrier for purification/separation. Under the influence of an external magnet, IMBs are attracted to coat one side of a test tube. IMBs specifically bound to targets can form a narrow brown stripe, whereas free IMBs will form a diffuse, yellow coating on the side of the test tube. Target analytes can aggregate initially dispersed IMBs in a sample concentration-dependent manner, yielding a color change from yellow to brown that can be seen with the naked eye. This assay combines the convenience of a lateral flow assay, allowing a one-step assay to finish within 15 min, with the sensitivity of an enzyme-linked immonosorbent assay.This report shows that immunomagnetic beads (IMBs) can act as the optical readout for assays, in addition to serving as the carrier for purification/separation. Under the influence of an external magnet, IMBs are attracted to coat one side of a test tube. IMBs specifically bound to targets can form a narrow brown stripe, whereas free IMBs will form a diffuse, yellow coating on the side of the test tube. Target analytes can aggregate initially dispersed IMBs in a sample concentration-dependent manner, yielding a color change from yellow to brown that can be seen with the naked eye. This assay combines the convenience of a lateral flow assay, allowing a one-step assay to finish within 15 min, with the sensitivity of an enzyme-linked immonosorbent assay. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07044a

  4. Generating and Describing Affective Eye Behaviors

    NASA Astrophysics Data System (ADS)

    Mao, Xia; Li, Zheng

    The manner of a person's eye movement conveys much about nonverbal information and emotional intent beyond speech. This paper describes work on expressing emotion through eye behaviors in virtual agents based on the parameters selected from the AU-Coded facial expression database and real-time eye movement data (pupil size, blink rate and saccade). A rule-based approach to generate primary (joyful, sad, angry, afraid, disgusted and surprise) and intermediate emotions (emotions that can be represented as the mixture of two primary emotions) utilized the MPEG4 FAPs (facial animation parameters) is introduced. Meanwhile, based on our research, a scripting tool, named EEMML (Emotional Eye Movement Markup Language) that enables authors to describe and generate emotional eye movement of virtual agents, is proposed.

  5. Eyeless initiates the expression of both sine oculis and eyes absent during Drosophila compound eye development.

    PubMed

    Halder, G; Callaerts, P; Flister, S; Walldorf, U; Kloter, U; Gehring, W J

    1998-06-01

    The Drosophila Pax-6 gene eyeless acts high up in the genetic hierarchy involved in compound eye development and can direct the formation of extra eyes in ectopic locations. Here we identify sine oculis and eyes absent as two mediators of the eye-inducing activity of eyeless. We show that eyeless induces and requires the expression of both genes independently during extra eye development. During normal eye development, eyeless is expressed earlier than and is required for the expression of sine oculis and eyes absent, but not vice versa. Based on the results presented here and those of others, we propose a model in which eyeless induces the initial expression of both sine oculis and eyes absent in the eye disc. sine oculis and eyes absent then appear to participate in a positive feedback loop that regulates the expression of all three genes. In contrast to the regulatory interactions that occur in the developing eye disc, we also show that in the embryonic head, sine oculis acts in parallel to eyeless and twin of eyeless, a second Pax-6 gene from Drosophila. Recent studies in vertebrate systems indicate that the epistatic relationships among the corresponding vertebrate homologs are very similar to those observed in Drosophila.

  6. Best practice eye care models.

    PubMed

    Qureshi, Babar M; Mansur, Rabiu; Al-Rajhi, Abdulaziz; Lansingh, Van; Eckert, Kristen; Hassan, Kunle; Ravilla, Thulasiraj; Muhit, Mohammad; Khanna, Rohit C; Ismat, Chaudhry

    2012-01-01

    Since the launching of Global Initiative, VISION 2020 "the Right to Sight" many innovative, practical and unique comprehensive eye care services provision models have evolved targeting the underserved populations in different parts of the World. At places the rapid assessment of the burden of eye diseases in confined areas or utilizing the key informants for identification of eye diseases in the communities are promoted for better planning and evidence based advocacy for getting / allocation of resources for eye care. Similarly for detection and management of diabetes related blindness, retinopathy of prematurity and avoidable blindness at primary level, the major obstacles are confronted in reaching to them in a cost effective manner and then management of the identified patients accordingly. In this regard, the concept of tele-ophthalmology model sounds to be the best solution. Whereas other models on comprehensive eye care services provision have been emphasizing on surgical output through innovative scales of economy that generate income for the program and ensure its sustainability, while guaranteeing treatment of the poorest of the poor.

  7. Best practice eye care models

    PubMed Central

    Qureshi, Babar M; Mansur, Rabiu; Al-Rajhi, Abdulaziz; Lansingh, Van; Eckert, Kristen; Hassan, Kunle; Ravilla, Thulasiraj; Muhit, Mohammad; Khanna, Rohit C; Ismat, Chaudhry

    2012-01-01

    Since the launching of Global Initiative, VISION 2020 “the Right to Sight” many innovative, practical and unique comprehensive eye care services provision models have evolved targeting the underserved populations in different parts of the World. At places the rapid assessment of the burden of eye diseases in confined areas or utilizing the key informants for identification of eye diseases in the communities are promoted for better planning and evidence based advocacy for getting / allocation of resources for eye care. Similarly for detection and management of diabetes related blindness, retinopathy of prematurity and avoidable blindness at primary level, the major obstacles are confronted in reaching to them in a cost effective manner and then management of the identified patients accordingly. In this regard, the concept of tele-ophthalmology model sounds to be the best solution. Whereas other models on comprehensive eye care services provision have been emphasizing on surgical output through innovative scales of economy that generate income for the program and ensure its sustainability, while guaranteeing treatment of the poorest of the poor. PMID:22944741

  8. Photoreceptor spectral sensitivity of the compound eyes of black soldier fly (Hermetia illucens) informing the design of LED-based illumination to enhance indoor reproduction.

    PubMed

    Oonincx, D G A B; Volk, N; Diehl, J J E; van Loon, J J A; Belušič, G

    2016-12-01

    Mating in the black soldier fly (BSF) is a visually mediated behaviour that under natural conditions occurs in full sunlight. Artificial light conditions promoting mating by BSF were designed based on the spectral characteristics of the compound eye retina. Electrophysiological measurements revealed that BSF ommatidia contained UV-, blue- and green-sensitive photoreceptor cells, allowing trichromatic vision. An illumination system for indoor breeding based on UV, blue and green LEDs was designed and its efficiency was compared with illumination by fluorescent tubes which have been successfully used to sustain a BSF colony for five years. Illumination by LEDs and the fluorescent tubes yielded equal numbers of egg clutches, however, the LED illumination resulted in significantly more larvae. The possibilities to optimize the current LED illumination system to better approximate the skylight illuminant and potentially optimize the larval yield are discussed.

  9. A dynamic response and eye scanning data base useful in the development of theories and methods for the description of control/display relationships

    NASA Technical Reports Server (NTRS)

    Klein, R.

    1972-01-01

    A set of specially prepared digital tapes is reported which contain synchronized measurements of pilot scanning behavior, control response, and vehicle response obtained during instrument landing system approaches made in a fixed-base DC-8 transport simulator. The objective of the master tape is to provide a common data base which can be used by the research community to test theories, models, and methods for describing and analyzing control/display relations and interactions. The experimental conditions and tasks used to obtain the data and the detailed format of the tapes are described. Conventional instrument panel and controls were used, with simulated vertical gust and glide slope beam bend forcing functions. Continuous pilot eye fixations and scan traffic on the panel were measured. Both flight director and standard localizer/glide slope types of approaches were made, with both fixed and variable instrument range sensitivities.

  10. A dynamic response and eye scanning data base useful in the development of theories and methods for the description of control/display relationships

    NASA Technical Reports Server (NTRS)

    Klein, R.

    1972-01-01

    A set of specially prepared digital tapes is reported which contain synchronized measurements of pilot scanning behavior, control response, and vehicle response obtained during instrument landing system approaches made in a fixed-base DC-8 transport simulator. The objective of the master tape is to provide a common data base which can be used by the research community to test theories, models, and methods for describing and analyzing control/display relations and interactions. The experimental conditions and tasks used to obtain the data and the detailed format of the tapes are described. Conventional instrument panel and controls were used, with simulated vertical gust and glide slope beam bend forcing functions. Continuous pilot eye fixations and scan traffic on the panel were measured. Both flight director and standard localizer/glide slope types of approaches were made, with both fixed and variable instrument range sensitivities.

  11. Eye mechanics and their implications for eye movement control

    NASA Astrophysics Data System (ADS)

    Koene, Ansgar Roald

    2002-11-01

    The topic of this thesis is the investigation of the mechanical properties of the oculomotor system and the implications of these properties for eye movement control. The investigation was conducted by means of computer models and simulations. This allowed us to combine data from anatomy, physiology and psychophysics with basic principles of physics (mechanics) and mathematics (geometry). In chapter 2 we investigate the degree to which mechanical and neural non-linearities contribute to the kinematic differences between centrifugal and centripetal saccades. On the basis of the velocity profiles of centrifugal and centripetal saccades we calculate the forces and muscle innervations during these eye movements. This was done using an inverted model of the eye plant. Our results indicate that the non-linear force-velocity relationship (i.e. muscle viscosity) of the muscles is probably the cause of the kinematic differences between centrifugal and centripetal saccades. In chapter 3 we calculate the adjustment of the saccadic command that is necessary to compensate for the eye plant non-linearities. These calculations show that the agonist and antagonist muscles require different net saccade signal gain changes. In order to better understand how this gain change is accomplished we use the inverted model of the eye plant (chapter 2) to calculate the muscle innervation profiles of saccades with different starting orientations. Based on these calculations we conclude that the saccade signal gain changes are accomplished primarily by changes in the magnitude of the saccade signal. In chapter 4 we examine the requirements that the oculomotor system must meet for the eye to be able to make desired gaze changes and fixate at various eye orientations. We first determine how the axes of action (i.e. unit moment vectors) of the muscles are related to eye orientation and the location of the effective muscle origin (i.e. the muscle pulleys). Next we show how this relation constrains

  12. How individuals with body dysmorphic disorder (BDD) process their own face: a quantitative and qualitative investigation based on an eye-tracking paradigm.

    PubMed

    Toh, Wei Lin; Castle, David J; Rossell, Susan L

    2017-05-01

    Body dysmorphic disorder (BDD) is characterised by repetitive behaviours and/or mental acts occurring in response to preoccupations with perceived flaws in physical appearance. Based on an eye-tracking paradigm, this study aimed to examine how individuals with BDD processed their own face. Participants were 21 BDD patients, 19 obsessive-compulsive disorder patients and 21 healthy controls (HC), who were age-, sex-, and IQ-matched. Stimuli were photographs of participants' own faces as well as those from the Pictures of Facial Affect battery. Outcome measures were affect recognition accuracy as well as spatial and temporal scanpath parameters. The BDD group exhibited significantly decreased recognition accuracy for their own face relative to the HC group, and this was most pronounced for those who had a key concern centred on their face. Individual qualitative scanpath analysis revealed restricted and extensive scanning behaviours in BDD participants with a facial preoccupation. Persons with severe BDD also exhibited more marked scanpath deficits. Future research should be directed at extending the current work by incorporating neuroimaging techniques, and investigations of eye-tracking focused on affected body parts in BDD. These could yield fruitful therapeutic applications via incorporation with existing treatment approaches.

  13. Occupational exposure to the whole body, extremities and to the eye lens in interventional radiology in Poland, as based on personnel dosimetry records at IFJ PAN

    NASA Astrophysics Data System (ADS)

    Szumska, Agnieszka; Budzanowski, M.; Kopeć, R.

    2014-11-01

    We report results of measurements of Hp(10) from whole body dosimeters (about 53 thousand readouts), of Hp(0.07) from finger ring dosimeters (23 thousand readouts) and of Hp(3) from eye lens dosimeters (100 readouts), issued in the years 2010-12 to over 150 medical departments in Poland which apply X-rays in radiology, interventional radiology (haemodynamic, angiology, cardiac surgery), urology, orthopaedics, electrophysiology or electro-cardiology. In all measurements thermoluminescence detectors (TLD) were used: the well-known standard MTS-N (LiF:Mg, Ti) for whole body and extremity dosimetry, and the high-sensitivity MCP-N (LiF:Mg, Cu, P) for eye lens dosimetry and environmental monitoring. We analysed the data base of the accredited Laboratory of Individual and Environmental Dosimetry (LADIS) at the Institute of Nuclear Physics PAN which offers its dosimetry service to these departments on a regular basis. We found that in the population of radiation workers that studied over the years 2010-2012 in 84%, 87%, and 34% of Hp(10), Hp(0.07) and Hp(3) measurements, respectively, the level of 0.1 mSv/quarter did not exceed, indicating lack of their occupational exposure. In the remaining 16%, 13% and 66% of individual cases, the 0.1 mSv/quarter exceeded, occasionally reaching several hundreds of mSv/quarter.

  14. On the comparison of visual discomfort generated by S3D and 2D content based on eye-tracking features

    NASA Astrophysics Data System (ADS)

    Iatsun, Iana; Larabi, Mohamed-Chaker; Fernandez-Maloigne, Christine

    2014-03-01

    The changing of TV systems from 2D to 3D mode is the next expected step in the telecommunication world. Some works have already been done to perform this progress technically, but interaction of the third dimension with humans is not yet clear. Previously, it was found that any increased load of visual system can create visual fatigue, like prolonged TV watching, computer work or video gaming. But watching S3D can cause another nature of visual fatigue, since all S3D technologies creates illusion of the third dimension based on characteristics of binocular vision. In this work we propose to evaluate and compare the visual fatigue from watching 2D and S3D content. This work shows the difference in accumulation of visual fatigue and its assessment for two types of content. In order to perform this comparison eye-tracking experiments using six commercially available movies were conducted. Healthy naive participants took part into the test and gave their answers feeling the subjective evaluation. It was found that watching stereo 3D content induce stronger feeling of visual fatigue than conventional 2D, and the nature of video has an important effect on its increase. Visual characteristics obtained by using eye-tracking were investigated regarding their relation with visual fatigue.

  15. Training the Eyes for Competition: Fighting Eyes.

    ERIC Educational Resources Information Center

    Williams, Darrell; Bradford, Vincent

    1989-01-01

    Fencers should be taught to discipline their eyes to focus on the opponent's hand. The rationale for this strategy as well as drills to develop "hand watching" skills are presented in this article. (IAH)

  16. Optical properties of the mouse eye

    PubMed Central

    Geng, Ying; Schery, Lee Anne; Sharma, Robin; Dubra, Alfredo; Ahmad, Kamran; Libby, Richard T.; Williams, David R.

    2011-01-01

    The Shack-Hartmann wavefront sensor (SHWS) spots upon which ocular aberration measurements depend have poor quality in mice due to light reflected from multiple retinal layers. We have designed and implemented a SHWS that can favor light from a specific retinal layer and measured monochromatic aberrations in 20 eyes from 10 anesthetized C57BL/6J mice. Using this instrument, we show that mice are myopic, not hyperopic as is frequently reported. We have also measured longitudinal chromatic aberration (LCA) of the mouse eye and found that it follows predictions of the water-filled schematic mouse eye. Results indicate that the optical quality of the mouse eye assessed by measurement of its aberrations is remarkably good, better for retinal imaging than the human eye. The dilated mouse eye has a much larger numerical aperture (NA) than that of the dilated human eye (0.5 NA vs. 0.2 NA), but it has a similar amount of root mean square (RMS) higher order aberrations compared to the dilated human eye. These measurements predict that adaptive optics based on this method of wavefront sensing will provide improvements in retinal image quality and potentially two times higher lateral resolution than that in the human eye. PMID:21483598

  17. Optical Coherence Tomography Based Observation of Natural History of Drusenoid Lesion in Eyes with Dry Age-Related Macular Degeneration

    PubMed Central

    Ouyang, Yanling; Heussen, Florian M.; Hariri, Amirhossein; Keane, Pearse A.; Sadda, Srinivas R.

    2013-01-01

    Purpose To use spectral domain optical coherence tomography (SD-OCT) to investigate risk factors predictive for development of atrophy of drusenoid lesions (drusen and drusenoid pigment epithelium detachment) in eyes with non-neovascular age-related macular degeneration (NNVAMD). Design Cohort study. Participants Forty-one eyes from 29 patients with NNVAMD. Methods Patients with NNVAMD who underwent registered SD-OCT imaging over a minimum period of six months, were reviewed. Drusenoid lesions that accompanied by new atrophy onset at 6 month or last follow up were further analyzed. Detailed lesion change was described throughout the study period. Odds ratios (OR) and risk for new local atrophy onset were calculated. Main Outcomes Measures Drusenoid lesion features and longitudinal changes in features including maximum lesion height, lesion diameter, lesion internal reflectivity, presence and extent of overlying intraretinal hyperreflective features (HRF). Subfoveal choroidal thickness and choroidal thickness measured below each lesion. Results 543 individual drusenoid lesions were identified at baseline, while 28 lesions developed during follow-up. The mean follow-up time was 21.3 ± 8.6 (range, 6-44) months. 3.2% (18/571) of drusenoid lesions progressed to atrophy within 18.3±9.5 (range: 5-28) months of initial visit. Drusenoid lesions with heterogenous internal reflectivity were significantly associated with new atrophy onset at 6 month (OR=5.614, 95% confidence interval (CI) =1.277-24.673) and new atrophy onset at last follow up (OR=7.005, CI=2.300-21.337). Lesions with presence of HRF also were significant predictors for new atrophy onset at 6 month (OR=30.161, CI=4.766-190.860) and at last follow up (OR=11.211, CI=2.513-50.019). Lesions with a baseline maximum height over 80 microns or choroidal thickness less than 135 microns showed positive association with the new atrophy onset at last follow up (OR=7.886, CI=2.105-29.538 and OR=3.796, CI=1

  18. Blindness in different types of eye disease. A study based on the records of the Department of Eye Diseases in the Medical University, Plovdiv for the period 1982-1991.

    PubMed

    Chilova-Atanassova, B; Hristov, B; Hristeva, S; Andreev, A; Dzheneva, M; Gyuleva, G; Petkova, D; Georgieva, E; Balian, A; Konareva, M

    1994-01-01

    Between 1982 and 1991, inclusive, a total of 13718 patients were treated in the Department of Eye Diseases in Plovdiv University of Medicine. Cataract patients formed the most numerous group (19.71%), followed by those with diseases of the retina (9.53%), glaucoma (7.95%), uveitis (4.9%), diseases of the cornea (3.86%), malignant tumors of the eyelids and the eyeball (2.29%) and diseases of the optic nerve (1.54%). Of these 13718 patients, 1727 (12.58%) had monocular and binocular vision below 0.08. The patients with visual acuity from 0 to 0.03 were 1330 (9.69%). Nosologically, they were distributed as follows: glacoma-422 (3.07%), eye traumas-281 (2.04%), diseases of the retina-270 (1.96%), diseases of the cornea-89 (0.64%), cataract-80 (0.58%), uveitis-77 (0.56%), malignant tumors of the eyelids and the eyeball-66 (0.48%), and diseases of the optic nerve-45 (0.32%). Glaucoma was found to be the most common cause of blindness among the patients treated in the Department of Eye Diseases, followed by eye traumas and disease of the retina. The importance of the vascular factor in inducing blindness is undeniably great. It is the underlying cause of the open-angle glaucoma, the diseases of the retina and the optic nerve.

  19. Tutorial on Biostatistics: Statistical Analysis for Correlated Binary Eye Data.

    PubMed

    Ying, Gui-Shuang; Maguire, Maureen G; Glynn, Robert; Rosner, Bernard

    2017-05-22

    To describe and demonstrate methods for analyzing correlated binary eye data. We describe non-model based (McNemar's test, Cochran-Mantel-Haenszel test) and model-based methods (generalized linear mixed effects model, marginal model) for analyses involving both eyes. These methods were applied to: (1) CAPT (Complications of Age-related Macular Degeneration Prevention Trial) where one eye was treated and the other observed (paired design); (2) ETROP (Early Treatment for Retinopathy of Prematurity) where bilaterally affected infants had one eye treated conventionally and the other treated early and unilaterally affected infants had treatment assigned randomly; and (3) AREDS (Age-Related Eye Disease Study) where treatment was systemic and outcome was eye-specific (both eyes in the same treatment group). In the CAPT (n = 80), treatment group (30% vision loss in treated vs. 44% in observed eyes) was not statistically significant (p = 0.07) when inter-eye correlation was ignored, but was significant (p = 0.01) with McNemar's test and the marginal model. Using standard logistic regression for unfavorable vision in ETROP, standard errors and p-values were larger for person-level covariates and were smaller for ocular covariates than using models accounting for inter-eye correlation. For risk factors of geographic atrophy in AREDS, two-eye analyses accounting for inter-eye correlation yielded more power than one-eye analyses and provided larger standard errors and p-values than invalid two-eye analyses ignoring inter-eye correlation. Ignoring inter-eye correlation can lead to larger p-values for paired designs and smaller p-values when both eyes are in the same group. Marginal models or mixed effects models using the eye as the unit of analysis provide valid inference.

  20. Effect of narrowing the base of support on the gait, gaze and quiet eye of elite ballet dancers and controls.

    PubMed

    Panchuk, Derek; Vickers, Joan N

    2011-08-01

    We determined the gaze and stepping behaviours of elite ballet dancers and controls as they walked normally and along progressively narrower 3-m lines (l0.0, 2.5 cm). The ballet dancers delayed the first step and then stepped more quickly through the approach area and onto the lines, which they exited more slowly than the controls, which stepped immediately but then slowed their gait to navigate the line, which they exited faster. Contrary to predictions, the ballet group did not step more precisely, perhaps due to the unique anatomical requirements of ballet dance and/or due to releasing the degrees of freedom under their feet as they fixated ahead more than the controls. The ballet group used significantly fewer fixations of longer duration, and their final quiet eye (QE) duration prior to stepping on the line was significantly longer (2,353.39 ms) than the controls (1,327.64 ms). The control group favoured a proximal gaze strategy allocating 73.33% of their QE fixations to the line/off the line and 26.66% to the exit/visual straight ahead (VSA), while the ballet group favoured a 'look-ahead' strategy allocating 55.49% of their QE fixations to the exit/VSA and 44.51% on the line/off the line. The results are discussed in the light of the development of expertise and the enhanced role of fixations and visual attention when more tasks become more constrained.

  1. Robot-assisted retinal vein cannulation with force-based puncture detection: Micron vs. the steady-hand eye robot.

    PubMed

    Gonenc, Berk; Tran, Nhat; Gehlbach, Peter; Taylor, Russell H; Iordachita, Iulian

    2016-08-01

    Retinal vein cannulation is a demanding procedure where therapeutic agents are injected into occluded retina veins. The feasibility of this treatment is limited due to challenges in identifying the moment of venous puncture, achieving cannulation and maintaining it throughout the drug delivery period. In this study, we integrate a force-sensing microneedle with two distinct robotic systems: the handheld micromanipulator Micron, and the cooperatively controlled Steady-Hand Eye Robot (SHER). The sensed tool-to-tissue interaction forces are used to detect venous puncture and extend the robots' standard control schemes with a new position holding mode (PHM) that assists the operator hold the needle position fixed and maintain cannulation for a longer time with less trauma on the vasculature. We evaluate the resulting systems comparatively in a dry phantom, stretched vinyl membranes. Results have shown that modulating the admittance control gain of SHER alone is not a very effective solution for preventing the undesired tool motion after puncture. However, after using puncture detection and PHM the deviation from the puncture point is significantly reduced, by 65% with Micron, and by 95% with SHER representing a potential advantage over freehand for both.

  2. Gaze-based rehearsal in children under 7: a developmental investigation of eye movements during a serial spatial memory task.

    PubMed

    Morey, Candice C; Mareva, Silvana; Lelonkiewicz, Jaroslaw R; Chevalier, Nicolas

    2017-03-12

    The emergence of strategic verbal rehearsal at around 7 years of age is widely considered a major milestone in descriptions of the development of short-term memory across childhood. Likewise, rehearsal is believed by many to be a crucial factor in explaining why memory improves with age. This apparent qualitative shift in mnemonic processes has also been characterized as a shift from passive visual to more active verbal mnemonic strategy use, but no investigation of the development of overt spatial rehearsal has informed this explanation. We measured serial spatial order reconstruction in adults and groups of children 5-7 years old and 8-11 years old, while recording their eye movements. Children, particularly the youngest children, overtly fixated late-list spatial positions longer than adults, suggesting that younger children are less likely to engage in covert rehearsal during stimulus presentation than older children and adults. However, during retention the youngest children overtly fixated more of the to-be-remembered sequences than any other group, which is inconsistent with the idea that children do nothing to try to remember. Altogether, these data are inconsistent with the notion that children under 7 do not engage in any attempts to remember. They are most consistent with proposals that children's style of remembering shifts around age 7 from reactive cue-driven methods to proactive, covert methods, which may include cumulative rehearsal.

  3. Correlative Evaluation of Mental and Physical Workload of Laparoscopic Surgeons Based on Surface Electromyography and Eye-tracking Signals.

    PubMed

    Zhang, Jian-Yang; Liu, Sheng-Lin; Feng, Qing-Min; Gao, Jia-Qi; Zhang, Qiang

    2017-09-11

    Surgeons' mental and physical workloads are major focuses of operating room (OR) ergonomics, and studies on this topic have generally focused on either mental workload or physical workload, ignoring the interaction between them. Previous studies have shown that physically demanding work may affect mental performance and may be accompanied by impaired mental processing and decreased performance. In this study, 14 participants were recruited to perform laparoscopic cholecystectomy (LC) procedures in a virtual simulator. Surface electromyography (sEMG) signals of the bilateral trapezius, bicipital, brachioradialis and flexor carpi ulnaris (FCU) muscles and eye-tracking signals were acquired during the experiment. The results showed that the least square means of muscle activity during the LC phases of surgery in an all-participants mixed effects model were 0.79, 0.81, and 0.98, respectively. The observed muscle activities in the different phases exhibited some similarity, while marked differences were found between the forearm bilateral muscles. Regarding mental workload, significant differences were observed in pupil dilation between the three phases of laparoscopic surgery. The mental and physical workloads of laparoscopic surgeons do not appear to be generally correlated, although a few significant negative correlations were found. This result further indicates that mental fatigue does markedly interfere with surgeons' operating movements.

  4. Autostereoscopic display with eye tracking

    NASA Astrophysics Data System (ADS)

    Tomono, Takao; Hoon, Kyung; Ha, Yong Soo; Kim, Sung-Sik; Son, Jung-Young

    2002-05-01

    Auto-stereoscopic 21-inch display with eye tracking having wide viewing zone and bright image was fabricated. The image of display is projected to retinal through several optical components. We calculated optical system for wider viewing zone by using Inverse-Ray Trace Method. The viewing zone of first model is 155mm (theoretical value: 161mm). We could widen viewing zone by controlling paraxial radius of curvature of spherical mirror, the distance between lenses and so on. The viewing zone of second model is 208mm. We used two spherical mirrors to obtain twice brightness. We applied eye-tracking system to the display system. Eye recognition is based on neural network card based on ZICS technology. We fabricated Auto-stereoscopic 21-inch display with eye tracking. We measured viewing zone based on illumination area. The viewing zone was 206mm, which was close to theoretical value. We could get twice brightness also. We could see 3D image according to position without headgear.

  5. Fixation based event-related fmri analysis: using eye fixations as events in functional magnetic resonance imaging to reveal cortical processing during the free exploration of visual images.

    PubMed

    Marsman, Jan Bernard C; Renken, Remco; Velichkovsky, Boris M; Hooymans, Johanna M M; Cornelissen, Frans W

    2012-02-01

    Eye movements, comprising predominantly fixations and saccades, are known to reveal information about perception and cognition, and they provide an explicit measure of attention. Nevertheless, fixations have not been considered as events in the analyses of data obtained during functional magnetic resonance imaging (fMRI) experiments. Most likely, this is due to their brevity and statistical properties. Despite these limitations, we used fixations as events to model brain activation in a free viewing experiment with standard fMRI scanning parameters. First, we found that fixations on different objects in different task contexts resulted in distinct cortical patterns of activation. Second, using multivariate pattern analysis, we showed that the BOLD signal revealed meaningful information about the task context of individual fixations and about the object being inspected during these fixations. We conclude that fixation-based event-related (FIBER) fMRI analysis creates new pathways for studying human brain function by enabling researchers to explore natural viewing behavior.

  6. Vestibular-Related Frontal Cortical Areas and Their Roles in Smooth-Pursuit Eye Movements: Representation of Neck Velocity, Neck-Vestibular Interactions, and Memory-Based Smooth-Pursuit

    PubMed Central

    Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo

    2011-01-01

    Smooth-pursuit eye movements are voluntary responses to small slow-moving objects in the fronto-parallel plane. They evolved in primates, who possess high-acuity foveae, to ensure clear vision about the moving target. The primate frontal cortex contains two smooth-pursuit related areas; the caudal part of the frontal eye fields (FEF) and the supplementary eye fields (SEF). Both areas receive vestibular inputs. We review functional differences between the two areas in smooth-pursuit. Most FEF pursuit neurons signal pursuit parameters such as eye velocity and gaze-velocity, and are involved in canceling the vestibulo-ocular reflex by linear addition of vestibular and smooth-pursuit responses. In contrast, gaze-velocity signals are rarely represented in the SEF. Most FEF pursuit neurons receive neck velocity inputs, while discharge modulation during pursuit and trunk-on-head rotation adds linearly. Linear addition also occurs between neck velocity responses and vestibular responses during head-on-trunk rotation in a task-dependent manner. During cross-axis pursuit–vestibular interactions, vestibular signals effectively initiate predictive pursuit eye movements. Most FEF pursuit neurons discharge during the interaction training after the onset of pursuit eye velocity, making their involvement unlikely in the initial stages of generating predictive pursuit. Comparison of representative signals in the two areas and the results of chemical inactivation during a memory-based smooth-pursuit task indicate they have different roles; the SEF plans smooth-pursuit including working memory of motion–direction, whereas the caudal FEF generates motor commands for pursuit eye movements. Patients with idiopathic Parkinson’s disease were asked to perform this task, since impaired smooth-pursuit and visual working memory deficit during cognitive tasks have been reported in most patients. Preliminary results suggested specific roles of the basal ganglia in memory-based smooth

  7. Paper-based fluorescent sensor for rapid naked-eye detection of acetylcholinesterase activity and organophosphorus pesticides with high sensitivity and selectivity.

    PubMed

    Chang, Jiafu; Li, Haiyin; Hou, Ting; Li, Feng

    2016-12-15

    Various strategies have been proposed for the sensing of acetylcholinesterase (AChE) activity and organophosphorus pesticides (OPs). However, the practical application of most methods is restricted by their intrinsic drawbacks such as complexity, long analysis time, and high cost. Thus, it is highly desirable to develop simple, fast and sensitive approaches for AChE activity and OPs detection. Herein, we reported a simple paper-based fluorescent sensor (PFS) based on the aggregation induced emission (AIE) effect of tetraphenylethylene (TPE) and the addition reaction capability of maleimide, which has been used as a powerful tool for rapid naked-eye detection of AChE activity and OPs. The introduction of TPE provides the probe with unique fluorescence property in solid state and is of great importance for improving the sensitivity of PFS. The hydrolysis product of acetylthiocholine catalyzed by AChE induced the maleimide ring destruction and activated the fluorescence performance of TPE. Given that AChE activity can be specifically inhibited by OPs, the as-proposed PFS can also be utilized for sensitive detection of OPs. Meanwhile, the variation of fluorescence signal can be readily detected by naked eyes, and low detection limits of 2.5mUmL(-1) and 0.5ngmL(-1) for AChE activity and OPs are obtained, respectively. Moreover, it has been successfully applied for AChE activity and OPs detection in diluted human serum samples, showing its great potential to be applied in real samples. Thus, this strategy possesses considerable advantages of simplicity, rapid detection, portability, cost efficiency and visualization.

  8. The EPIC-Norfolk Eye Study: rationale, methods and a cross-sectional analysis of visual impairment in a population-based cohort

    PubMed Central

    Khawaja, Anthony P; Chan, Michelle P Y; Hayat, Shabina; Broadway, David C; Luben, Robert; Garway-Heath, David F; Sherwin, Justin C; Yip, Jennifer L Y; Dalzell, Nichola; Wareham, Nicholas J; Khaw, Kay-Tee; Foster, Paul J

    2013-01-01

    Objectives To summarise the methods of the European Prospective Investigation of Cancer (EPIC)-Norfolk Eye Study, and to present data on the prevalence of visual impairment and associations with visual impairment in the participants. Design A population-based cross-sectional study nested within an on-going prospective cohort study (EPIC). Setting East England population (the city of Norwich and its surrounding small towns and rural areas). Participants A total of 8623 participants aged 48–92 years attended the Eye Study and underwent assessment of visual acuity, autorefraction, biometry, tonometry, corneal biomechanical measures, scanning laser polarimetry, confocal scanning laser ophthalmoscopy, fundal photography and automated perimetry. Outcome measures Visual impairment was defined according to the WHO classification and the UK driving standard, and was based on presenting visual acuity. Summary measures of other ophthalmic measurements are also presented. Results The prevalence (95% CI) of WHO-defined moderate-to-severe visual impairment and blindness was 0.74% (0.55% to 0.92%). The prevalence (95% CI) of presenting visual acuity worse than the UK driving standard was 5.87% (5.38% to 6.37%). Older age was significantly associated with visual impairment or blindness (p<0.001). Presenting visual acuity worse than UK driving standard was associated with older age (p<0.001), female sex (p=0.005) and lower educational level (p=0.022). Conclusions The prevalence of blindness and visual impairment in this selected population was low. Visual impairment was more likely in older participants, women and those with a lower educational level. PMID:23516272

  9. European eye bank association.

    PubMed

    Jones, Gary L A; Ponzin, Diego; Pels, Elisabeth; Maas, Hanneke; Tullo, Andrew B; Claerhout, Ilse

    2009-01-01

    The European Eye Bank Association (EEBA) is a technical-scientific organization for eye banks. Founded in 1989 with the simple objective of sharing information on eye banking, the Association is today the leading pan-national association in Europe dedicated to the advancement of eye banking and an authoritative reference point for eye banks which work according to quality standards. The Association establishes and maintains an agreed set of medical and technical standards, promotes the collection of data on eye bank activities and processes, provides opportunities for the discussion of all aspects of eye banking practice, including eye donor selection and procurement, relevant research and development, education and training in eye banking, and maintains linkage with national and international corneal transplant communities and relevant bodies. The recent introduction of a more structured and focused committee, a permanent secretariat, the development of a website has enabled the Association to establish closer links and collaborative activities with key regulatory bodies and to provide a more constant exchange of clinical, scientific and technical ideas and best practice with fellow professionals by means of its annual meetings, the EEBA directory and website, and a regular newsletter. The EEBA is a scientific organization committed to defining minimum standards and to encouraging eye banks to maintain the highest possible standards for quality and safety. Through its annual meetings, and the collection and exchange of detailed information from member eye banks, the Association can rightly claim to speak with a confident and representative voice on eye banking in Europe. Copyright 2009 S. Karger AG, Basel.

  10. Ocular Emergencies: Red Eye.

    PubMed

    Tarff, Andreina; Behrens, Ashley

    2017-05-01

    "Red eye" is used as a general term to describe irritated or bloodshot eyes. It is a recognizable sign of an acute/chronic, localized/systemic underlying inflammatory condition. Conjunctival injection is most commonly caused by dryness, allergy, visual fatigue, contact lens overwear, and local infections. In some instances, red eye can represent a true ocular emergency that should be treated by an ophthalmologist. A comprehensive assessment of red eye conditions is required to preserve the patients visual function. Severe ocular pain, significant photophobia, decreased vision, and history of ocular trauma are warning signs demanding immediate ophthalmological consultation. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Fellow eyes of giant retinal breaks.

    PubMed Central

    Freeman, H M

    1978-01-01

    INCIDENCE OF RETINAL BREAKS AND DETACHMENT IN FELLOW EYES. The fellow eyes of 226 giant retinal breaks were followed in order to determine the incidence and natural course of chorioretinal and vitreous pathology. During the period of observation which ranged from 18 months to 16 years, the incidence of retinal breaks and retinal detachment increased from 36.1 percent to 51.3 percent. By the end of the follow-up period, the incidence of bilateral giant retinal breaks was 12.8 percent; retinal tears 11.9 percent, retinal holes 10.2 percent, retinal dialysis 0.4 percent, and retinal detachment 15.9 percent. The average duration of follow-up was 3.7 years, therefore, the incidence of retinal breaks in fellow eyes is probably significantly higher. VITREORETINAL CHANGES PRECEDING THE DEVELOPMENT OF RETINAL BREAKS. Syneresis, liquefaction, and condensation of the vitreous base were observed in the majority fellow eyes that developed retinal tears or giant retinal breaks. Follow-up of fellow eyes revealed that the development of a giant retinal break is often preceded by increasing white with pressure associated with increasing condensation of the vitreous base. MANAGEMENT OF FELLOW EYES. Bcause of the high incidence of retinal breaks developing in the fellow eye, regular and thorough examination of the vitreous and retinal breaks even though the fundus may appear normal at the initial examination. PROPHYLACTIC TREATMENT. This study suggests that prophylactic treatment is beneficial in the management of fellow eyes of giant retinal breaks. During this study, retinal breaks developed in 27.3 percent of untreated eyes and in 2.4 percent of eyes treated prophylactically. PROPHYLACTIC TREATMENT OF FELLOW EYES OF GIANT RETINAL BREAKS. Its seems prudent to prophylactically treat retinal holes or dialyses in eyes without retinal detachment with cryotherapy. Scleral bucking seems justified in the prophylactic treatment of eyes with retinal tears of lattice-like degeneration with

  12. MO-F-CAMPUS-I-04: Patient Eye-Lens Dose Reduction in Routine Brain CT Examinations Using Organ-Based Tube Current Modulation and In-Plane Bismuth Shielding

    SciTech Connect

    Tsai, Hui-Yu; Liao, Ying-Lan; Chen, Jun-Rong

    2015-06-15

    Purpose: The purpose of this study is to assess eye-lens dose for patients who underwent brain CT examinations using two dose reduction Methods: organ-based tube current modulation (OBTCM) and in-plane bismuth shielding method. Methods: This study received institutional review board approval; written informed consent to participate was obtained from all patients. Ninety patients who underwent the routine brain CT examination were randomly assigned to three groups, ie. routine, OBTCM, and bismuth shield. The OBTCM technique reduced the tube current when the X-ray tube rotates in front of patients’ eye-lens region. The patients in the bismuth shield group were covered one-ply bismuth shield in the eyes’ region. Eye-lens doses were measured using TLD-100H chips and the total effective doses were calculated using CT-Expo according to the CT scanning parameters. The surface doses for patients at off-center positions were assessed to evaluate the off-centering effect. Results: Phantom measurements indicates that OBTCM technique could reduced by 26% to 28% of the surface dose to the eye lens, and increased by 25% of the surface dose at the opposed incident direction at the angle of 180°. Patients’ eye-lens doses were reduced 16.9% and 30.5% dose of bismuth shield scan and OBTCM scan, respectively compared to the routine scan. The eye-lens doses were apparently increased when the table position was lower than isocenter. Conclusion: Reducing the dose to the radiosensitive organs, such as eye lens, during routine brain CT examinations could lower the radiation risks. The OBTCM technique and in-plane bismuth shielding could be used to reduce the eye-lens dose. The eye-lens dose could be effectively reduced using OBTCM scan without interfering the diagnostic image quality. Patient position relative the CT gantry also affects the dose level of the eye lens. This study was supported by the grants from the Ministry of Science and Technology of Taiwan (MOST103-2314-B-182

  13. Neural constraints on eye motion in human eye-head saccades.

    PubMed

    Misslisch, H; Tweed, D; Vilis, T

    1998-02-01

    We examined two ways in which the neural control system for eye-head saccades constrains the motion of the eye in the head. The first constraint involves Listing's law, which holds ocular torsion at zero during head-fixed saccades. During eye-head saccades, does this law govern the eye's motion in space or in the head? Our subjects, instructed to saccade between space-fixed targets with the head held still in different positions, systematically violated Listing's law of the eye in space in a way that approximately, but not perfectly, preserved Listing's law of the eye in head. This finding implies that the brain does not compute desired eye position based on the desired gaze direction alone but also considers head position. The second constraint we studied was saturation, the process where desired-eye-position commands in the brain are "clipped" to keep them within an effective oculomotor range (EOMR), which is smaller than the mechanical range of eye motion. We studied the adaptability of the EOMR by asking subjects to make head-only saccades. As predicted by current eye-head models, subjects failed to hold their eyes still in their orbits. Unexpectedly, though, the range of eye-in-head motion in the horizontal-vertical plane was on average 31% smaller in area than during normal eye-head saccades, suggesting that the EOMR had been reduced by effort of will. Larger reductions were possible with altered visual input: when subjects donned pinhole glasses, the EOMR immediately shrank by 80%. But even with its reduced EOMR, the eye still moved into the "blind" region beyond the pinhole aperture during eye-head saccades. Then, as the head movement brought the saccade target toward the pinhole, the eyes reversed their motion, anticipating or roughly matching the target's motion even though it was still outside the pinhole and therefore invisible. This finding shows that the backward rotation of the eye is timed by internal computations, not by vision. When subjects wore

  14. Penetrating eye injuries in road traffic accidents.

    PubMed

    Patel, B C; Morgan, L H

    1988-03-01

    A review of all penetrating eye injuries treated by the Manchester Eye Hospital over four years (1 February 1982-31 January 1986) was undertaken. One hundred and ninety-six penetrating eye injuries were seen, of which 16 (8.2%) were due to road traffic accidents. Eight patients (nine eyes) were seen in the 12 months prior to the introduction of the seat-belt legislation on 1 February 1983. None of these patients was wearing a seat-belt whereas two of the eight patients (10 eyes) seen after the seat-belt legislation were. Both these patients suffered severe visual loss due to intraocular glass from shattered windscreens. Three patients had bilateral penetrating eye injuries, one before and two after the seat-belt legislation. Two of the nine eyes involved prior to the legislation and three of the 10 eyes after the legislation had an eventual visual acuity of 6/12 or better. In the majority of patients, failure to wear seat-belts or defective use is to blame. Flying glass from shattered toughened windscreens is a preventable danger. Nine of the 16 patients were first seen in the general accident and emergency department and, of these, seven did not have visual acuities recorded prior to referral to an ophthalmologist. The importance of measurement of the visual acuity and detection of an afferent pupillary defect is stressed based on these findings.

  15. Bio-inspired hemispherical compound eye camera

    NASA Astrophysics Data System (ADS)

    Xiao, Jianliang; Song, Young Min; Xie, Yizhu; Malyarchuk, Viktor; Jung, Inhwa; Choi, Ki-Joong; Liu, Zhuangjian; Park, Hyunsung; Lu, Chaofeng; Kim, Rak-Hwan; Li, Rui; Crozier, Kenneth B.; Huang, Yonggang; Rogers, John A.

    2014-03-01

    Compound eyes in arthropods demonstrate distinct imaging characteristics from human eyes, with wide angle field of view, low aberrations, high acuity to motion and infinite depth of field. Artificial imaging systems with similar geometries and properties are of great interest for many applications. However, the challenges in building such systems with hemispherical, compound apposition layouts cannot be met through established planar sensor technologies and conventional optics. We present our recent progress in combining optics, materials, mechanics and integration schemes to build fully functional artificial compound eye cameras. Nearly full hemispherical shapes (about 160 degrees) with densely packed artificial ommatidia were realized. The number of ommatidia (180) is comparable to those of the eyes of fire ants and bark beetles. The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors, which were fabricated in the planar geometries and then integrated and elastically transformed to hemispherical shapes. Imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes).

  16. Eye proprioception may provide real time eye position information.

    PubMed

    Wang, Jing; Pan, Yujun

    2013-03-01

    Because of the frequency of eye movements, online knowledge of eye position is crucial for the accurate spatial perception and behavioral navigation. Both the internal monitoring signal (corollary discharge) of eye movements and the eye proprioception signal are thought to contribute to the localization of the eye position in the orbit. However, the functional role of these two eye position signals in spatial cognition has been disputed for more than a century. The predominant view proposes that the online analysis of eye position is exclusively provided by the corollary discharge signal, while the eye proprioception signal only plays a role in the long-term calibration of the oculomotor system. However, increasing evidence from recent behavioral and physiological studies suggests that the eye proprioception signal may play a role in the online monitoring of eye position. The purpose of this review is to discuss the feasibility and possible function of the eye proprioceptive signal for online monitoring of eye position.

  17. Proposed classification of posterior staphylomas based on analyses of eye shape by three-dimensional magnetic resonance imaging and wide-field fundus imaging.

    PubMed

    Ohno-Matsui, Kyoko

    2014-09-01

    To determine the incidence and types of posterior staphylomas in eyes with pathologic myopia by analyzing the entire eye shape by 3-dimensional (3D) magnetic resonance imaging (MRI). Observational, case series. A total of 105 patients with pathologic myopia (spherical equivalent <-8.0 diopters or axial length ≥26.5 mm) were examined by 3D MRI and Optos (Optos, PLC, Dunfermline, Scotland). Staphyloma was defined as an outpouching of the wall of the eye that had a radius of curvature less than the surrounding curvature of the wall of the eye. The presence and types of staphylomas were determined by the entire eye shape in 3D MRI scans. Fundus abnormalities suggesting the staphyloma border were analyzed in the fundus images, fundus autofluorescence images, and infrared images by Optos. Incidence and types of posterior staphylomas, and the correlation between the type of staphyloma by MRI and the Optos images. A total of 198 eyes (105 patients) met the inclusion criteria of pathologic myopia (mean age, 64.3±11.5 years; mean axial length, 30.0±2.3 mm). Among 198 eyes, 98 (49.5%) had no staphylomas in 3D MRI scans and showed a barrel-shaped globe. The other 100 eyes (50.5%) had posterior staphyloma by 3D MRI. The most predominant type was wide, macular staphyloma (74% of eyes with staphyloma), followed by narrow, macular staphyloma (14% of eyes with staphyloma). In eyes with peripapillary and nasal staphylomas, the change of the curvature was slight and the eye had a nasally distorted shape. Optos images showed pigmentary abnormalities or abnormal reflectance along the staphyloma border. The patients with staphylomas were significantly older and had significantly worse visual function and more frequent chorioretinal changes than patients without staphyloma. Three-dimensional MRI was useful in analyzing the shape of eyes with and without staphyloma. Even in elderly individuals with severe myopia, approximately one half of the patients did not show

  18. Facts About Pink Eye

    MedlinePlus

    ... occur in both eyes and often accompanies a common cold or respiratory tract infection. Laboratory tests usually are not needed to diagnose ... by using artificial tears for the dryness and cold packs for the inflammation. ... neonatorum. Common symptoms include eye discharge and puffy, red eyelids ...

  19. Photorefraction of the Eye

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-01-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical…

  20. Photorefraction of the Eye

    ERIC Educational Resources Information Center

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-01-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical…

  1. Understanding pink eye

    USDA-ARS?s Scientific Manuscript database

    Pink eye (PE) is a physiological tuber disorder that can result in serious processing complications and storage losses. The earliest external symptoms consist of an ephemeral pinkish discoloration around tuber eyes, predominately at the bud end of the tuber. These pinkish areas can then develop into...

  2. An Eye for Learning.

    ERIC Educational Resources Information Center

    Ostwald, Thomas

    1995-01-01

    Presents a hands-on activity as an excellent starting point for investigations related to the eye. Involves making a simple model of the vertebrate eye to illustrate the formation of an upside-down image on the retina by the lens. Links to investigations in numerous science disciplines including astronomy, genetics, biology, earth science, and…

  3. An Eye for Learning.

    ERIC Educational Resources Information Center

    Ostwald, Thomas

    1995-01-01

    Presents a hands-on activity as an excellent starting point for investigations related to the eye. Involves making a simple model of the vertebrate eye to illustrate the formation of an upside-down image on the retina by the lens. Links to investigations in numerous science disciplines including astronomy, genetics, biology, earth science, and…

  4. Association Between Serum 25-Hydroxyvitamin D Levels and Dry Eye in Korean Adults: A Study Based on Korean National Health and Nutrition Examination Survey, 2010–2011

    PubMed Central

    Kim, Min Ji; Kim, Yun-Jin; Lee, Sang-Yeoup; Lee, Jeong-Gyu; Jeong, Dong-Wook; Kim, Yun Hee

    2017-01-01

    Background Dry eye is a common disease. Many patients continue to experience residual symptoms despite optimal treatment. Thus, new treatment options are required. The purpose of this study was to evaluate the association between serum 25-hydroxyvitamin D [25(OH)D] levels and dry eye. Methods This study was performed using data from the fifth Korean National Health and Nutrition Examination Survey, which is a cross-sectional study of the Korean population that was conducted from 2010 to 2011. We included adults aged >19 years who underwent ophthalmologic interviews and examinations. We excluded subjects who had comorbid conditions (rheumatoid arthritis, thyroid disease, chronic kidney disease, or depression) that are associated with dry eye. The subjects were divided into normal and dry eye groups. The dry eye group consisted of those who had clinically diagnosed dry eye syndrome or symptoms. Multiple logistic regression analysis was conducted to determine the association between serum 25(OH)D levels and dry eye. Results In the univariate model, the 25(OH)D levels were lower in the dry eye group than in the normal group (P=0.01). A significant association was found between severe vitamin D deficiency (<10 ng/mL) and dry eye (P=0.04). However, after multivariate adjustment, the statistical significance of the association disappeared (P-values= 0.49, vitamin D insufficiency; P=0.33, vitamin D deficiency; P=0.18, severe vitamin D deficiency). Conclusion Severe vitamin D deficiency was associated with dry eye in an unadjusted model, but the association was not statistically significant after adjustment. PMID:28360983

  5. The questionably dry eye.

    PubMed Central

    Mackie, I. A.; Seal, D. V.

    1981-01-01

    This paper is concerned with the recognition of the dry eye when the clinical diagnosis is in doubt and other external eye diseases may be present. Papillary conjunctivitis is common to the dry eye as well as other pathological conditions and confuses the diagnosis. We have correlated the factors involved in the assessment for dryness. We have shown that particulate matter in the unstained tear film is associated with low tear lysozyme concentration. Tear flow and tear lysozyme are not necessarily interrelated, but a low lysozyme concentration (tear lysozyme ratio < 1.0) is associated with keratoconjunctivitis sicca. The Schirmer I test can produce false positive results, and we have suggested a modification to overcome this. This modified test will detect the eye with severely depleted lysozyme secretion, but it is unreliable for detecting the eye with moderately depleted secretion. We find that its lowest normal limit should be considered as 6 mm. Images PMID:7448154

  6. Object-Based Visual Attention in 8-Month-Old Infants: Evidence from an Eye-Tracking Study

    ERIC Educational Resources Information Center

    Bulf, Hermann; Valenza, Eloisa

    2013-01-01

    Visual attention is one of the infant's primary tools for gathering relevant information from the environment for further processing and learning. The space-based component of visual attention in infants has been widely investigated; however, the object-based component of visual attention has received scarce interest. This scarcity is…

  7. Estimating peak skin and eye lens dose from neuroperfusion examinations: use of Monte Carlo based simulations and comparisons to CTDIvol, AAPM Report No. 111, and ImPACT dosimetry tool values.

    PubMed

    Zhang, Di; Cagnon, Chris H; Villablanca, J Pablo; McCollough, Cynthia H; Cody, Dianna D; Zankl, Maria; Demarco, John J; McNitt-Gray, Michael F

    2013-09-01

    CT neuroperfusion examinations are capable of delivering high radiation dose to the skin or lens of the eyes of a patient and can possibly cause deterministic radiation injury. The purpose of this study is to: (a) estimate peak skin dose and eye lens dose from CT neuroperfusion examinations based on several voxelized adult patient models of different head size and (b) investigate how well those doses can be approximated by some commonly used CT dose metrics or tools, such as CTDIvol, American Association of Physicists in Medicine (AAPM) Report No. 111 style peak dose measurements, and the ImPACT organ dose calculator spreadsheet. Monte Carlo simulation methods were used to estimate peak skin and eye lens dose on voxelized patient models, including GSF's Irene, Frank, Donna, and Golem, on four scanners from the major manufacturers at the widest collimation under all available tube potentials. Doses were reported on a per 100 mAs basis. CTDIvol measurements for a 16 cm CTDI phantom, AAPM Report No. 111 style peak dose measurements, and ImPACT calculations were performed for available scanners at all tube potentials. These were then compared with results from Monte Carlo simulations. The dose variations across the different voxelized patient models were small. Dependent on the tube potential and scanner and patient model, CTDIvol values overestimated peak skin dose by 26%-65%, and overestimated eye lens dose by 33%-106%, when compared to Monte Carlo simulations. AAPM Report No. 111 style measurements were much closer to peak skin estimates ranging from a 14% underestimate to a 33% overestimate, and with eye lens dose estimates ranging from a 9% underestimate to a 66% overestimate. The ImPACT spreadsheet overestimated eye lens dose by 2%-82% relative to voxelized model simulations. CTDIvol consistently overestimates dose to eye lens and skin. The ImPACT tool also overestimated dose to eye lenses. As such they are still useful as a conservative predictor of dose for CT

  8. Estimating peak skin and eye lens dose from neuroperfusion examinations: Use of Monte Carlo based simulations and comparisons to CTDIvol, AAPM Report No. 111, and ImPACT dosimetry tool values

    PubMed Central

    Zhang, Di; Cagnon, Chris H.; Villablanca, J. Pablo; McCollough, Cynthia H.; Cody, Dianna D.; Zankl, Maria; Demarco, John J.; McNitt-Gray, Michael F.

    2013-01-01

    Purpose: CT neuroperfusion examinations are capable of delivering high radiation dose to the skin or lens of the eyes of a patient and can possibly cause deterministic radiation injury. The purpose of this study is to: (a) estimate peak skin dose and eye lens dose from CT neuroperfusion examinations based on several voxelized adult patient models of different head size and (b) investigate how well those doses can be approximated by some commonly used CT dose metrics or tools, such as CTDIvol, American Association of Physicists in Medicine (AAPM) Report No. 111 style peak dose measurements, and the ImPACT organ dose calculator spreadsheet. Methods: Monte Carlo simulation methods were used to estimate peak skin and eye lens dose on voxelized patient models, including GSF's Irene, Frank, Donna, and Golem, on four scanners from the major manufacturers at the widest collimation under all available tube potentials. Doses were reported on a per 100 mAs basis. CTDIvol measurements for a 16 cm CTDI phantom, AAPM Report No. 111 style peak dose measurements, and ImPACT calculations were performed for available scanners at all tube potentials. These were then compared with results from Monte Carlo simulations. Results: The dose variations across the different voxelized patient models were small. Dependent on the tube potential and scanner and patient model, CTDIvol values overestimated peak skin dose by 26%–65%, and overestimated eye lens dose by 33%–106%, when compared to Monte Carlo simulations. AAPM Report No. 111 style measurements were much closer to peak skin estimates ranging from a 14% underestimate to a 33% overestimate, and with eye lens dose estimates ranging from a 9% underestimate to a 66% overestimate. The ImPACT spreadsheet overestimated eye lens dose by 2%–82% relative to voxelized model simulations. Conclusions: CTDIvol consistently overestimates dose to eye lens and skin. The ImPACT tool also overestimated dose to eye lenses. As such they are still

  9. Herpes zoster eye complications: rates and trends.

    PubMed

    Yawn, Barbara P; Wollan, Peter C; St Sauver, Jennifer L; Butterfield, Linda C

    2013-06-01

    To provide population-based data on the risk, types, and outcomes of eye involvement in herpes zoster (HZ). A cohort study based on review of the medical records of patients in whom HZ was diagnosed between January 1, 1980, and December 31, 2007, was performed. Herpes zoster was confirmed by the presence of the typical rash and symptoms or by laboratory testing, and eye involvement was confirmed by ophthalmologists' evaluation. Information was collected on all eye diagnoses and on HZ eye-related visits, treatments, procedures, and outcomes. Of the 7370 individuals with HZ in any dermatome, 184 (2.5%) had eye involvement. The mean age of the 184 was 62.6 years, and 5 cases occurred in patients younger than 21. Overall, 6.5% (12) were immunosuppressed at the time of the eye complications. The rate of increase in HZ eye involvement was 23% by decade from 1980 to 2007. Common eye complications were keratitis (n=144, 76.2%), uveitis/iritis (n=88, 46.6%), and conjunctivitis (n=67, 35.4%). Recurrent keratitis and recurrent iritis/uveitis occurred in 6.9% (13) and 7.4% (14), respectively. Outcomes included 6 patients (3.3%) with new vision decrements to 20/200 or worse. Two individuals had successful corneal transplants. Another 6 individuals (3.3%) had lid ptosis that affected vision, including 1 elderly woman with permanent unilateral tarsorrhaphy. Severe HZ eye pain was reported to be directly responsible for 1 unsuccessful suicide attempt. Acute retinal necrosis did not develop in any individual. A mean of 10.8 eye visits per patient with HZ and eye involvement was reported to continue for a mean of 308 days. Eye complications are common and result in considerable health care use and permanent vision decrement in about 6.6% (6) of individuals with HZ eye involvement. Most health care use and long-term adverse outcomes occurred in patients in whom prevention of HZ with the zoster vaccine would be possible. Copyright © 2013 Mayo Foundation for Medical Education and

  10. Cyanoacrylate Adhesives in Eye Wounds.

    DTIC Science & Technology

    EYE, *WOUNDS AND INJURIES), (*ADHESIVES, EYE), (*ACRYLIC RESINS, ADHESIVES), CORNEA , HEALING, TISSUES(BIOLOGY), TOLERANCES(PHYSIOLOGY), NECROSIS, SURGICAL SUPPLIES, STRENGTH(PHYSIOLOGY), SURGERY, THERAPY

  11. Advocacy for eye care.

    PubMed

    Ravilla, Thulasiraj D; Ramasamy, Dhivya

    2012-01-01

    The effectiveness of eye care service delivery is often dependant on how the different stakeholders are aligned. These stakeholders range from the ministries of health who have the capacity to grant government subsidies for eye care, down to the primary healthcare workers who can be enrolled to screen for basic eye diseases. Advocacy is a tool that can help service providers draw the attention of key stakeholders to a particular area of concern. By enlisting the support, endorsement and participation of a wider circle of players, advocacy can help to improve the penetration and effectiveness of the services provided. There are several factors in the external environmental that influence the eye care services - such as the availability of trained manpower, supply of eye care consumables, government rules and regulations. There are several instances where successful advocacy has helped to create an enabling environment for eye care service delivery. Providing eye care services in developing countries requires the support - either for direct patient care or for support services such as producing trained manpower or for research and dissemination. Such support, in the form of financial or other resources, can be garnered through advocacy.

  12. Antiangiogenic Eye Gene Therapy.

    PubMed

    Corydon, Thomas J

    2015-08-01

    The idea of treating disease in humans with genetic material was conceived over two decades ago and with that a promising journey involving development and efficacy studies in cells and animals of a large number of novel therapeutic reagents unfolded. In the footsteps of this process, successful gene therapy treatment of genetic conditions in humans has shown clear signs of efficacy. Notably, significant advancements using gene supplementation and silencing strategies have been made in the field of ocular gene therapy, thereby pinpointing ocular gene therapy as one of the compelling "actors" bringing gene therapy to the clinic. Most of all, this success has been facilitated because of (1) the fact that the eye is an effortlessly accessible, exceedingly compartmentalized, and immune-privileged organ offering a unique advantage as a gene therapy target, and (2) significant progress toward efficient, sustained transduction of cells within the retina having been achieved using nonintegrating vectors based on recombinant adeno-associated virus and nonintegrating lentivirus vectors. The results from in vivo experiments and trials suggest that treatment of inherited retinal dystrophies, ocular angiogenesis, and inflammation with gene therapy can be both safe and effective. Here, the progress of ocular gene therapy is examined with special emphasis on the potential use of RNAi- and protein-based antiangiogenic gene therapy to treat exudative age-related macular degeneration.

  13. Cord blood serum-based eye drops: the impact of donor haematological and obstetric factors on the variability of epidermal growth factor levels.

    PubMed

    Versura, Piera; Buzzi, Marina; Giannaccare, Giuseppe; Grillini, Marco; Terzi, Adriana; Pagliaro, Pasqualepaolo; Campos, Emilio C

    2014-01-01

    Cord blood serum (CBS)-based eye drops are successfully used in corneal epithelial wound healing and are prepared to supply a known amount of epidermal growth factor (EGF). Product standardisation includes expensive EGF dosage in all cord blood (CB) units. The influence of donor obstetric and haematological characteristics on EGF content was evaluated, to exclude unsuitable CBS and pre-select those CB units able to provide the correct EGF supply for healing corneal wounds. Data were retrospectively collected from 135 donors included in the Emilia Romagna Cord Blood Bank records. Obstetric characteristics, parity and gestational age of the mother, sex, birth weight and Apgar score of the neonate, placental weight, duration of labour and mode of delivery were considered. Haematological characteristics, CD34+ cell number, and total nucleated cell, white blood cell and platelet counts were recorded. EGF content in CB units was estimated by enzyme-linked immunosorbent assay. Statistical evaluation was performed by Mann-Whitney unpaired and Student's t tests. Correlations between variables were evaluated by using Pearson's (r) or Spearman's (ρ) correlation coefficients. EGF content was significantly higher in CBS from donors aged <30 years and after vaginal deliveries as compared with scheduled Caesarean sections (1,386±580 vs 1,106±391 pg/mL; P=0.002). EGF content was significantly correlated with duration of labour (r=0.45; P=0.0001), number of CD34+ cells/mL (r=0.3; P=0.002) particularly in vaginal deliveries (r=0.36; P=0.003), mother's age (-0.25; P=0.005), neonate's birth weight (r=0.27; P=0.005), and total nucleated cell (r=0.25; P=0.006), white cell (r=0.29; P=0.001) and platelet (r=0.24; P=0.009) counts. No significant correlations were found between EGF content and parity, gestational age, placental weight, neonate's sex or Apgar scores. EGF levels are higher in CB units from younger mothers (<30 years), with longer labour duration (>6 hours), and higher CD34

  14. The Bird's Eye View of Community Colleges: A Behavioral Typology of First-Time Students Based on Cluster Analytic Classification

    ERIC Educational Resources Information Center

    Bahr, Peter Riley

    2010-01-01

    The development of a typology of community college students is a topic of long-standing and growing interest among educational researchers, policy-makers, administrators, and other stakeholders, but prior work on this topic has been limited in a number of important ways. In this paper, I develop a behavioral typology based on students'…

  15. Faith-Based Media Literacy Education: A Look at the Past with an Eye toward the Future

    ERIC Educational Resources Information Center

    Iaquinto, Stephanie; Keeler, John

    2012-01-01

    This article addresses several fundamental questions about faith-based media literacy education in the United States, including how the assumptions, motivations, goals, and pedagogy of those Christians who are operating within a media literacy framework come together to create a unique approach to teaching media literacy. After briefly reviewing…

  16. "Kindergarten, can I have your eyes and ears?" politeness and teacher directive choices in inquiry-based science classrooms

    NASA Astrophysics Data System (ADS)

    Oliveira, Alandeom Wanderlei

    2009-12-01

    This study explores elementary teachers' social understandings and employment of directives and politeness while facilitating inquiry science lessons prior and subsequent to their participation in a summer institute in which they were introduced to the scholarly literature on regulative discourse (directives used by teachers to regulate student behavior). A grounded theory analysis of the institute professional development activities revealed that teachers developed an increased awareness of the authoritative functions served by impolite or direct directives (i.e., pragmatic awareness). Furthermore, a comparative microethnographic analysis of participants' inquiry-based classroom practices revealed that after the institute teachers demonstrated an increased ability to share authority with students by strategically making directive choices that were more polite, indirect, inclusive, involvement-focused and creative. Such ability led to a reduced emphasis on teacher regulation of student compliance with classroom behavioral norms and an increased focus on the discursive organization of the inquiry-based science learning/teaching process. Despite teachers' increased pragmatic awareness, teacher-student linguistic relationships did not become entirely symmetrical subsequent to their participation in the summer institute (i.e., teacher authority was not completely relinquished or lost). Based on such findings, it is argued that teachers need to develop higher levels of pragmatic awareness to become effectively prepared to engage in language-mediated teacher-student interaction in the context of inquiry-based science classroom discourse.

  17. The Bird's Eye View of Community Colleges: A Behavioral Typology of First-Time Students Based on Cluster Analytic Classification

    ERIC Educational Resources Information Center

    Bahr, Peter Riley

    2010-01-01

    The development of a typology of community college students is a topic of long-standing and growing interest among educational researchers, policy-makers, administrators, and other stakeholders, but prior work on this topic has been limited in a number of important ways. In this paper, I develop a behavioral typology based on students'…

  18. CATS EYES Adjustment Procedures

    DTIC Science & Technology

    1993-04-01

    AL-TR-1 993-0025 AD-A264 069 CATS EYES ADJUSTMENT PROCEDURES A R M Joseph C. Antonio DTIC S ELECTET University of Dayton Research Institute MAY 13...Final November 1992 - January 1993 4. TITLE AND SUBTITLE S. FUNDING NUMBERS C F33615-90-C-0005 CATS EYES Adjustment Procedures PE - 62205F 6. AUTHOR(S) PR...the loss of NVG performance resulting from improper goggle adjustments. This report describes correct adjustment procedures for the CATS EYES NVG system

  19. Eye movement tics.

    PubMed Central

    Shawkat, F; Harris, C M; Jacobs, M; Taylor, D; Brett, E M

    1992-01-01

    An 8-year-old girl presented with opsoclonus-like eye movement and an 18 month history of intermittent facial tics. Investigations were all normal. Electro-oculography showed the eye movements to be of variable amplitude (10-40 degrees), with no intersaccadic interval, and with a frequency of 3-4 Hz. Saccades, smooth pursuit, optokinetic, and vestibular reflexes were all normal. These abnormal eye movements eventually disappeared. It is thought that they were a form of ocular tics. PMID:1477052

  20. Eye-Safe Lidar

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.

    1989-01-01

    Laser infrared radar (lidar) undergoing development harmless to human eyes, consists almost entirely of solid-state components, and offers high range resolution. Operates at wavelength of about 2 micrometers. If radiation from such device strikes eye, almost completely absorbed by cornea without causing damage, even if aimed directly at eye. Continuous-wave light from laser oscillator amplified and modulated for transmission from telescope. Small portion of output of oscillator fed to single-mode fiber coupler, where mixed with return pulses. Intended for remote Doppler measurements of winds and differential-absorption measurements of concentrations of gases in atmosphere.

  1. Postoperative refraction in the second eye having cataract surgery.

    PubMed

    Leffler, Christopher T; Wilkes, Martin; Reeves, Juliana; Mahmood, Muneera A

    2011-01-01

    Introduction. Previous cataract surgery studies assumed that first-eye predicted and observed postoperative refractions are equally important for predicting second-eye postoperative refraction. Methods. In a retrospective analysis of 173 patients having bilateral sequential phacoemulsification, multivariable linear regression was used to predict the second-eye postoperative refraction based on refractions predicted by the SRK-T formula for both eyes, the first-eye postoperative refraction, and the difference in IOL selected between eyes. Results. The first-eye observed postoperative refraction was an independent predictor of the second eye postoperative refraction (P < 0.001) and was weighted more heavily than the first-eye predicted refraction. Compared with the SRK-T formula, this model reduced the root-mean-squared (RMS) error of the predicted refraction by 11.3%. Conclusions. The first-eye postoperative refraction is an independent predictor of the second-eye postoperative refraction. The first-eye predicted refraction is less important. These findings may be due to interocular symmetry.

  2. Postoperative Refraction in the Second Eye Having Cataract Surgery

    PubMed Central

    Leffler, Christopher T.; Wilkes, Martin; Reeves, Juliana; Mahmood, Muneera A.

    2011-01-01

    Introduction. Previous cataract surgery studies assumed that first-eye predicted and observed postoperative refractions are equally important for predicting second-eye postoperative refraction. Methods. In a retrospective analysis of 173 patients having bilateral sequential phacoemulsification, multivariable linear regression was used to predict the second-eye postoperative refraction based on refractions predicted by the SRK-T formula for both eyes, the first-eye postoperative refraction, and the difference in IOL selected between eyes. Results. The first-eye observed postoperative refraction was an independent predictor of the second eye postoperative refraction (P < 0.001) and was weighted more heavily than the first-eye predicted refraction. Compared with the SRK-T formula, this model reduced the root-mean-squared (RMS) error of the predicted refraction by 11.3%. Conclusions. The first-eye postoperative refraction is an independent predictor of the second-eye postoperative refraction. The first-eye predicted refraction is less important. These findings may be due to interocular symmetry. PMID:24533181

  3. A web-based information system for management and analysis of patient data after refractive eye surgery.

    PubMed

    Zuberbuhler, Bruno; Galloway, Peter; Reddy, Aravind; Saldana, Manuel; Gale, Richard

    2007-12-01

    The aim was to develop a software tool for refractive surgeons using a standard user-friendly web-based interface, providing the user with a secure environment to protect large volumes of patient data. The software application was named "Internet-based refractive analysis" (IBRA), and was programmed with the computer languages PHP, HTML and JavaScript, attached to the opensource MySQL database. IBRA facilitated internationally accepted presentation methods including the stability chart, the predictability chart and the safety chart; it was able to perform vector analysis for the course of a single patient or for group data. With the integrated nomogram calculation, treatment could be customised to reduce the postoperative refractive error. Multicenter functions permitted quality-control comparisons between different surgeons and laser units.

  4. Self-reported assessment of visual function in a population-based study: the SEE project. Salisbury Eye Evaluation.

    PubMed

    Valbuena, M; Bandeen-Roche, K; Rubin, G S; Munoz, B; West, S K

    1999-02-01

    To report on the usefulness of the Activities of Daily Vision Scale (ADVS) questionnaire for assessing visual functioning, a population-based sample of elderly Americans. The ADVS questionnaire was administered to a population-based sample of 2520 community-dwelling individuals 65 to 84 years of age in Salisbury, MD. Items and subscales were evaluated for internal consistency, item discrimination, and content validity. Published subscale groupings and item associations in our population were compared for coherence using correlation, factor, and cluster analyses. Whole-sample and race- and gender-specific analyses were conducted. External validity was explored by regressing ADVS scores on standard psychophysical vision measures. ADVS scores were skewed to high visual functioning levels; approximately 60% of the population had function scores of 95 or better (of a possible 100). The overall, night driving, and near vision scales were internally consistent and had strong item-subscale associations; the day driving and glare subscales were not acceptable regarding these properties. The far vision subscale was acceptably scalable but only weakly differentiated from the other subscales. Overall, night driving, near vision, and far vision scores were all statistically and independently associated with multiple psychophysical vision measures. Findings were consistent across race and gender subgroups. As assessed by the ADVS, reported visual functioning is high in our representative older population. The overall scale and selected subscales effectively distinguish persons along a spectrum of ability. They correlate with measures of visual impairment in a reasonable way and thus hold promise for risk factor investigations. The published day driving and glare subscales should be examined for relevance and consistency before being applied in population-based settings. Methods specific to population-based settings should be investigated for their ability to better elicit

  5. How to perform irrigation of the eye.

    PubMed

    Marsden, Janet

    2016-02-03

    rationale and key points: This article aims to help nurses to understand the importance of performing irrigation immediately following chemical injury to the eye, and outlines the most effective technique. It is essential that irrigation of the eye is understood and performed correctly. Chemical injury to the eye is an ophthalmic emergency. It presents a serious risk to the patient's vision and may cause blindness. The length of time the chemical remains in contact with the eye determines the severity of the injury. Immediate irrigation of the eye is essential to minimise preventable loss of vision. REFLECTIVE ACTIVITY: Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How you would ensure immediate irrigation following chemical injury to the eye in your clinical area. 2. How you know when you have irrigated the eye for long enough, if you have previously performed this procedure, and how reading this article might influence your practice. Subscribers can upload their reflective accounts at: rcni.com/portfolio .

  6. Modelling human eye under blast loading.

    PubMed

    Esposito, L; Clemente, C; Bonora, N; Rossi, T

    2015-01-01

    Primary blast injury (PBI) is the general term that refers to injuries resulting from the mere interaction of a blast wave with the body. Although few instances of primary ocular blast injury, without a concomitant secondary blast injury from debris, are documented, some experimental studies demonstrate its occurrence. In order to investigate PBI to the eye, a finite element model of the human eye using simple constitutive models was developed. The material parameters were calibrated by a multi-objective optimisation performed on available eye impact test data. The behaviour of the human eye and the dynamics of mechanisms occurring under PBI loading conditions were modelled. For the generation of the blast waves, different combinations of explosive (trinitrotoluene) mass charge and distance from the eye were analysed. An interpretation of the resulting pressure, based on the propagation and reflection of the waves inside the eye bulb and orbit, is proposed. The peculiar geometry of the bony orbit (similar to a frustum cone) can induce a resonance cavity effect and generate a pressure standing wave potentially hurtful for eye tissues.

  7. Brain-machine interface for eye movements.

    PubMed

    Graf, Arnulf B A; Andersen, Richard A

    2014-12-09

    A number of studies in tetraplegic humans and healthy nonhuman primates (NHPs) have shown that neuronal activity from reach-related cortical areas can be used to predict reach intentions using brain-machine interfaces (BMIs) and therefore assist tetraplegic patients by controlling external devices (e.g., robotic limbs and computer cursors). However, to our knowledge, there have been no studies that have applied BMIs to eye movement areas to decode intended eye movements. In this study, we recorded the activity from populations of neurons from the lateral intraparietal area (LIP), a cortical node in the NHP saccade system. Eye movement plans were predicted in real time using Bayesian inference from small ensembles of LIP neurons without the animal making an eye movement. Learning, defined as an increase in the prediction accuracy, occurred at the level of neuronal ensembles, particularly for difficult predictions. Population learning had two components: an update of the parameters of the BMI based on its history and a change in the responses of individual neurons. These results provide strong evidence that the responses of neuronal ensembles can be shaped with respect to a cost function, here the prediction accuracy of the BMI. Furthermore, eye movement plans could be decoded without the animals emitting any actual eye movements and could be used to control the position of a cursor on a computer screen. These findings show that BMIs for eye movements are promising aids for assisting paralyzed patients.

  8. The Eyes as Windows Into Other Minds.

    PubMed

    Grossmann, Tobias

    2017-01-01

    Eyes have been shown to play a key role during human social interactions. However, to date, no comprehensive cross-discipline model has provided a framework that can account for uniquely human responses to eye cues. In this review, I present a framework that brings together work on the phylogenetic, ontogenetic, and neural bases of perceiving and responding to eyes. Specifically, I argue for a two-process model: a first process that ensures privileged attention to information encoded in the eyes and is important for the detection of other minds and a second process that permits the decoding of information contained in the eyes concerning another person's emotional and mental states. To some degree, these processes are unique to humans, emerge during different times in infant development, can be mapped onto distinct but interconnected brain regions, and likely serve critical functions in facilitating cooperative interactions in humans. I also present evidence to show that oxytocin is a key modulator of sensitive responding to eye cues. Viewing eyes as windows into other minds can therefore be considered a hallmark feature of human social functioning deeply rooted in our biology.

  9. Comparison of the clinical effects of carbomer-based lipid-containing gel and hydroxypropyl-guar gel artificial tear formulations in patients with dry eye syndrome: a 4-week, prospective, open-label, randomized, parallel-group, noninferiority study.

    PubMed

    Wang, Tsung-Jen; Wang, I-Jong; Ho, Jau-Der; Chou, Hsiu-Chu; Lin, Szu-Yuan; Huang, Man-Ching

    2010-01-01

    Most marketed artificial tears are substitutes for the aqueous layers of the tear film; therefore, frequent instillation of artificial tears is necessary. Newer gel-, cellulose-, and mineral oil-based formulations have been designed to overcome the disadvantages of current aqueous tear substitutes by offering prolonged retention times. The aim of this study was to compare the efficacy, safety, and local tolerance of artificial tears containing carbomer-based lipids or hydroxypropyl (HP)-guar gel in patients with dry eye syndrome. A 4-week, prospective, randomized, parallel-group, comparative, noninferiority study was conducted at the Taipei Medical University Hospital (Taipei, Taiwan) in patients with dry eye syndrome who were randomly assigned to 1 of 2 treatment groups: the carbomer-based lipid-containing (CBLC) gel group and the HP-guar gel group. The primary end point was global assessment of study treatment by the patients at weeks 2 and 4. All patients met the diagnostic criteria of impaired tear function and ocular surface abnormalities. Outcomes measured at baseline and 2 and 4 weeks included Schirmer's test values, tear breakup time (TBUT), and a patient subjective assessment of symptoms. Safety and tolerability were assessed by clinically significant changes in terms of incidence of adverse events and conducted by unmasked investigators. A total of 30 Taiwanese patients with dry eye syndrome were included and randomly assigned to the 2 treatment groups: the mean (SD) age was 40.37 (14.96) years in the CBLC gel group and 49.49 (12.20) years in the HP-guar gel group. At baseline, the mean (SD) Schirmer's test value was 4.53 (2.28) mm in the right eye and 5.13 (2.42) mm in the left eye in the CBLC gel group; 4.40 (2.16) mm in the right eye and 4.20 (1.78) mm in the left eye for the HP-guar gel group. The mean (SD) for both eyes was 4.83 (2.36) mm in the CBLC gel group and 4.30 (2.08) mm in the HP-guar gel group. There was no statistically significant

  10. Autologous serum eye drops for dry eye.

    PubMed

    Pan, Qing; Angelina, Adla; Marrone, Michael; Stark, Walter J; Akpek, Esen K

    2017-02-28

    Theoretically, autologous serum eye drops (AS) offer a potential advantage over traditional therapies on the assumption that AS not only serve as a lacrimal substitute to provide lubrication but contain other biochemical components that allow them to mimic natural tears more closely. Application of AS has gained popularity as second-line therapy for patients with dry eye. Published studies on this subject indicate that autologous serum could be an effective treatment for dry eye. We conducted this review to evaluate the efficacy and safety of AS given alone or in combination with artificial tears as compared with artificial tears alone, saline, placebo, or no treatment for adults with dry eye. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2016), Embase (January 1980 to July 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to July 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database (December 2016) and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 July 2016. We included randomized controlled trials (RCTs) that compared AS versus artificial tears for treatment of adults with dry eye. Two review authors independently screened all titles and abstracts and assessed full-text reports of potentially eligible trials. Two review authors extracted data and assessed risk of bias and characteristics of included trials. We contacted investigators to ask for missing data. For both primary and

  11. Cassidy eye exam

    NASA Image and Video Library

    2013-07-11

    ISS036-E-018262 (11 July 2013) --- NASA astronaut Chris Cassidy, Expedition 36 flight engineer, performs a visual exam using an eye chart (out of frame) in the Destiny laboratory of the International Space Station.

  12. Cassidy eye exam

    NASA Image and Video Library

    2013-07-11

    ISS036-E-018265 (11 July 2013) --- NASA astronaut Chris Cassidy, Expedition 36 flight engineer, performs a visual exam using an eye chart (out of frame) in the Destiny laboratory of the International Space Station.

  13. Cat-Eyed Saturn

    NASA Image and Video Library

    2006-04-13

    Bright, high altitude clouds, like those imaged here, often appear more filamentary or streak-like than clouds imaged at slightly deeper levels in Saturn atmosphere. This view also shows one of the many cat eye vortices.

  14. Common Eye Disorders

    MedlinePlus

    ... Click here to see demonstration ) Top of Page Cataract Cataract is a clouding of the eye’s lens and ... cause of vision loss in the United States. Cataracts can occur at any age because of a ...

  15. Pink Eye (Conjunctivitis)

    MedlinePlus

    ... E (IgE). This antibody triggers special cells called mast cells in the mucous lining of your eyes and ... reactions, such as a combination of antihistamines and mast cell stabilizers Drugs that help control inflammation, such as ...

  16. Eye Injuries (For Parents)

    MedlinePlus

    ... the eyelid. Others, like those that happen during sports activities, can be serious and require medical attention. Signs and Symptoms redness stinging or burning watering sensitivity to light blurred vision swelling of the eyelids discoloration around the eye ...

  17. Eyes, Bulging (Proptosis)

    MedlinePlus

    ... them know what to expect during the evaluation. Warning signs In people with bulging eyes, certain symptoms ... child When to see a doctor People with warning signs should see a doctor as soon as ...

  18. Smoking and Eye Health

    MedlinePlus

    ... that is most common in women after menopause. Smoking increases the risk of serious vision loss in people with other eye diseases. And when women smoke during pregnancy they are more likely to give birth prematurely, ...

  19. Dry eye syndrome

    MedlinePlus

    ... of dry eyes include: Dry environment or workplace (wind, air conditioning) Sun exposure Smoking or second-hand ... NOT smoke and avoid second-hand smoke, direct wind, and air conditioning. Use a humidifier, especially in ...

  20. Eye Disease Simulations

    MedlinePlus

    ... NIH Campus Mission Statement As part of the federal government’s National Institutes of Health (NIH), the National Eye ... National Institutes of Health (NIH) and is the Federal government’s lead agency for vision research that leads to ...