Sample records for colour vision impairment

  1. Colour vision impairment in workers exposed to low concentrations of toluene.

    PubMed

    Zavali?, M; Turk, R; Bogadi-Sare, A; Skender, L

    1996-06-01

    Colour vision was examined by the Lanthony-D-15 desaturated test in 41 women exposed to toluene and in 29 non-exposed referents. Toluene exposure was evaluated by methods of environmental and biological monitoring. In the exposed group the median value of toluene in air was 35 ppm (range 11.2-49.9 ppm). Quantitative colour vision impairment was expressed as colour confusion index and colour confusion index corrected for alcohol intake. Qualitative impairment was expressed as normal, yellow-blue, red-green range or complex impairment. Statistical analysis showed the index values to be significantly correlated with age in both groups. In the exposed group they were significantly higher than in the non-exposed group. There was no significant difference in the prevalence of impairment in the blue-yellow range between the examined groups, although the prevalence of impairment in the exposed group was higher than in the non-exposed one. Results suggest that exposure to low toluene concentrations may induce colour vision impairment in women. PMID:8905935

  2. Colour, vision and ergonomics.

    PubMed

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age. PMID:22317623

  3. All Vision Impairment

    MedlinePLUS

    ... Research at NEI Education Programs Training and Jobs All Vision Impairment Listen Vision Impairment Defined Vision impairment ... being blind by the U.S. definition.) The category “All Vision Impairment” includes both low vision and blindness. ...

  4. Unconventional colour vision.

    PubMed

    Marshall, Justin; Arikawa, Kentaro

    2014-12-15

    Butterflies and stomatopods are certainly outliers in their unconventional colour sense and despite some similarities at first glance, in fact sample the world of colour very differently. In one way, butterflies are relatively conventional, possessing either tri-or tetrachromatic colour vision, then just adding one or several task-specific sub-mechanisms onto this. It is the stomatopods so far that have really pushed the boat out into a different colour vision mechanism. Over 400 million years of independent evolution they have arrived at a solution with more in common with the way a satellite sensor examines the colours of the earth than other animals. Remember, however, that unconventional colour vision is not just the realm of the serially polychromatic. Apparently waterfleas with four classes of spectral receptors living in ponds operate a task-specific spectral sense with no need, or indeed neural processing power, to construct a complex discriminatory mechanism. It seems they have the butterfly added-extra set without the more complex comparative chromatic mechanisms, although in truth, conclusive behavioural proof is lacking. Behavioural observation of colour vision in the ecological context of each animal is vital before making the distinction between conventional and unconventional. Just counting spectral sensitivities is never enough. PMID:25514002

  5. Polymorphism and Adaptation of Primate Colour Vision

    E-print Network

    Fedigan, Linda M.

    Chapter 13 Polymorphism and Adaptation of Primate Colour Vision Amanda D. Melin, Chihiro Hiramatsu levels. Primates have evolved a unique ability for trichromatic colour vision from a dichromatic in extensive colour vision variability in New World monkeys, where trichromats and dichromats are found

  6. Ultraviolet Colour Vision and Ornamentation in Bluethroats

    Microsoft Academic Search

    Staffan Andersson; Trond Amundsen

    1997-01-01

    Many birds see in the ultraviolet (300-400 nm), but there is limited evidence for colour communication (signalling by spectral shape independently of brightness) in this 'hidden' waveband. Such data are critical for the understanding of extravagant plumage colours, some of which show considerable UV reflectance. We investigated UV colour vision in female social responses to the male UV\\/violet ornament in

  7. Colour vision: parallel pathways intersect in Drosophila.

    PubMed

    Kelber, Almut; Henze, Miriam J

    2013-12-01

    In the last one hundred years, colour vision has been demonstrated in bees and many other insects. But the underlying neural wiring remained elusive. A new study on Drosophila melanogaster combining behavioural and genetic tools yields surprising insights. PMID:24309280

  8. Ultraviolet colour vision and ornamentation in bluethroats

    PubMed Central

    Andersson, S.; Amundsen, T.

    1997-01-01

    Many birds see in the ultraviolet (300–400 nm), but there is limited evidence for colour communication (signalling by spectral shape independently of brightness) in this 'hidden' waveband. Such data are critical for the understanding of extravagant plumage colours, some of which show considerable UV reflectance. We investigated UV colour vision in female social responses to the male UV/violet ornament in bluethroats, Luscinia s. svecica. In an outdoor aviary at the breeding grounds, 16 females were each presented with a unique pair of males of equal age. In UVR (UV reduction) males, sunblock chemicals reduced only the UV reflectance and thereby the spectral shape (colour) of the throat ornament. In NR (neutral reduction) males, an achromatic pigment in the same base solvent (preen gland fat) was used for a corresponding but uniform brightness reduction. Both colour and brightness effects were invisible to human eyes, and were monitored by spectrometry. In 13 of the 16 trials, the female associated most with the NR male, a preference that implies that UV colour vision is used in mate choice by female bluethroats. Reflectance differences between one-year-old and older males were significant only in UV, suggestive of a UV colour cue in age-related mate preferences.

  9. Impairments to Vision

    MedlinePLUS

    ... re looking. Glaucoma and Retinitis Pigmentosa Ring or Donut Scotoma Left Field Homonymous Hemianopia Although very different ... severe loss of side vision. A ring or donut shaped scotoma is an area of reduced vision ...

  10. The Physics of Colour Vision.

    ERIC Educational Resources Information Center

    Goldman, Martin

    1985-01-01

    An elementary physical model of cone receptor cells is explained and applied to complexities of human color vision. One-, two-, and three-receptor systems are considered, with the later shown to be the best model for the human eye. Color blindness is also discussed. (DH)

  11. Vision Impairment and Blindness

    MedlinePLUS

    ... blindness in the United States are age-related eye diseases: macular degeneration, cataract and glaucoma. Other eye disorders, ... and braille books. The sooner vision loss or eye disease is found and treated, the greater your chances ...

  12. Colour vision at very high altitude.

    PubMed

    Leid, J; Campagne, J M

    2001-01-01

    The goal of our study was to evaluate colour vision during high-altitude mountain climbing without supplemental oxygen. Two Himalayan expeditions were invited to test their colour perception at both the highest possible altitude and on the largest possible number of subjects. The panel desaturated D15 was used, because only a simple test could be transported to those altitudes. There were 2 evaluations (i.e., 4 eyes) at 7,000 m during the first expedition in 1997, and 3 evaluations (i.e., 6 eyes) at 6,500 m during the second expedition in 1998. The results were in perfect agreement and can be considered practically normal for all 5 mountain climbers. PMID:12269339

  13. Colour vision deficiency in the medical profession.

    PubMed Central

    Spalding, J A

    1999-01-01

    Colour is often used as a sign in medicine, yet there have been few studies into the effects of a colour vision deficiency (CVD) on doctors' medical skills. Using a literature search, the results indicate the prevalence of CVD in the medical profession and its effects on medical skills. For the congenital form among male doctors in the United Kingdom, the prevalence is shown to be probably about the same as for the population at large; i.e. 8%. However, the data is insufficient for any estimate to be made of the small number of female doctors and for the acquired forms of CVD. The effect on skills is also shown. Because of certain features of their work, general practitioners may have special problems. Thus, it is concluded that medical students and doctors should be screened for the deficiency and advised about it, and that there should be more study of the effects of CVD on decision-making in general practice and some specialties. PMID:10562750

  14. Adaptive plasticity during the development of colour vision

    Microsoft Academic Search

    Hans-Joachim Wagner; Ronald H. H. Kröger

    2005-01-01

    Colour vision greatly enhances the discriminatory and cognitive capabilities of visual systems and is found in a great majority of vertebrates and many invertebrates. However, colour coding visual systems are confronted with the fact that the external stimuli are ambiguous because they are subject to constant variations of luminance and spectral composition. Furthermore, the transmittance of the ocular media, the

  15. Colour vision in diurnal and nocturnal hawkmoths.

    PubMed

    Kelber, Almut; Balkenius, Anna; Warrant, Eric J

    2003-08-01

    Diurnal and nocturnal hawkmoths (Sphingidae, Lepidoptera) have three spectral types of receptor sensitive to ultraviolet, blue and green light. As avid flower visitors and pollinators, they use olfactory and visual cues to find and recognise flowers. Moths of the diurnal species Macroglossum stellatarum and the nocturnal species Deilephila elpenor, Hyles lineata and Hyles gallii use and learn the colour of flowers. Nocturnal species can discriminate flowers at starlight intensities when humans and honeybees are colour-blind. M. stellatarum can use achromatic, intensity-related cues if colour cues are absent, and this is probably also true for D. elpenor. Both species can recognise colours even under a changed illumination colour. PMID:21680465

  16. Dark Adaptation of Colour Vision in Diabetic Subjects

    NASA Astrophysics Data System (ADS)

    Márquez-Gamiño, S.; Cortés-Peñaloza, J. L.; Pérez-Hernández, J. U.; Cruz-Rodríguez, E.; Caudillo, C.

    2004-09-01

    Eye disease, a late complication of diabetes mellitus (DM) occurs even under a careful glicemic control. It includes optic nerve, retina, vitreous humor, crystalline lens and pupillary affection. The physiopathological process could be independent of blood glucose levels or start at initial stages of the disease. Photoreceptors have specific physiological functions. The functional substrate of day light or colour vision in superior primates, the cones have different spectral sensitivity, 455, 530 and 560 nm. The rods, maximal sensitivity at 505 nm, are much more sensitive to light than are cones. Dark adaptation was tested to evaluate functional impairment differences in photoreceptors of diabetic subjects. 14 DM2 (type 2 DM), and 5 DM1 (type 1 DM) patients, as well as 9 healthy subjects were studied. Retinal affected individuals, were excluded. Dark adaptation curves seemed to be different between DM, and healthy subjects. Cones, specially those sensitive to 560 nm type, seems to be more labile to DM, as demonstrated by the lack of sensitivity to low, and medium intensity stimuli. Medical Physics and elementary Biomedical Engineering exhibited to be useful to discern malfunction between different types of photorreceptors. The inexpensive method used could be applied for early color vision alteration detection.

  17. Enhancing Color Representation for the Color Vision Impaired

    E-print Network

    Paris-Sud XI, Université de

    Enhancing Color Representation for the Color Vision Impaired Jia-Bin Huang1 , Sih-Ying Wu2 a fast re-coloring algorithm to im- prove the accessibility for the color vision impaired. Compared to people with normal color vision, people with color vision impairment have diffi- culty in distinguishing

  18. A Standalone Vision Impairments Simulator for Java Swing Applications

    NASA Astrophysics Data System (ADS)

    Oikonomou, Theofanis; Votis, Konstantinos; Korn, Peter; Tzovaras, Dimitrios; Likothanasis, Spriridon

    A lot of work has been done lately in an attempt to assess accessibility. For the case of web rich-client applications several tools exist that simulate how a vision impaired or colour-blind person would perceive this content. In this work we propose a simulation tool for non-web JavaTM Swing applications. Developers and designers face a real challenge when creating software that has to cope with a lot of interaction situations, as well as specific directives for ensuring an accessible interaction. The proposed standalone tool will assist them to explore user-centered design and important accessibility issues for their JavaTM Swing implementations.

  19. Low Vision Aids for Visually Impaired Children

    ERIC Educational Resources Information Center

    Schurink, J.; Cox, R. F. A.; Cillessen, A. H. N.; van Rens, G. H. M. B.; Boonstra, F. N.

    2011-01-01

    It is a widely accepted belief in clinical practice that children with a visual impairment can profit from the use of a low vision aid (LVA). However, we found a considerable gap in our scientific understanding of LVA use, particularly in young children. This is the reason for the analysis presented in this paper. A selected overview of LVA use in…

  20. Psychological Adjustment in Adolescents with Vision Impairment

    ERIC Educational Resources Information Center

    Pinquart, Martin; Pfeiffer, Jens P.

    2012-01-01

    The present study compared psychological adjustment of 158 adolescents with vision impairment and 158 sighted adolescents with a matched-pair design using the Strengths and Difficulties Questionnaire. Adolescent self-reports and teacher reports on emotional problems, peer problems, and total difficulties showed higher scores in students with…

  1. Impaired colour discrimination among workers exposed to styrene: relevance of a urinary metabolite

    Microsoft Academic Search

    T Eguchi; R Kishi; I Harabuchi; J Yuasa; Y Arata; Y Katakura; H Miyake

    1995-01-01

    OBJECTIVES--To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. METHODS--Colour discrimination was examined in 64 male workers exposed to

  2. Orientation tuning in human colour vision at detection threshold

    PubMed Central

    Gheiratmand, Mina; Mullen, Kathy T.

    2014-01-01

    We measure the orientation tuning of red-green colour and luminance vision at low (0.375?c/deg) and mid (1.5?c/deg) spatial frequencies using the low-contrast psychophysical method of subthreshold summation. Orientation bandwidths of the underlying neural detectors are found using a model involving Minkowski summation of the rectified outputs of a bank of oriented filters. At 1.5?c/deg, we find orientation-tuned detectors with similar bandwidths for chromatic and achromatic contrast. At 0.375?c/deg, orientation tuning is preserved with no change in bandwidth for achromatic stimuli, however, for chromatic stimuli orientation tuning becomes extremely broad, compatible with detection by non-oriented colour detectors. A non-oriented colour detector, previously reported in single cells in primate V1 but not psychophysically in humans, can transmit crucial information about the color of larger areas or surfaces whereas orientation-tuned detectors are required to detect the colour or luminance edges that delineate an object's shape. PMID:24594749

  3. Stochastic spineless expression creates the retinal mosaic for colour vision.

    PubMed

    Wernet, Mathias F; Mazzoni, Esteban O; Celik, Arzu; Duncan, Dianne M; Duncan, Ian; Desplan, Claude

    2006-03-01

    Drosophila colour vision is achieved by R7 and R8 photoreceptor cells present in every ommatidium. The fly retina contains two types of ommatidia, called 'pale' and 'yellow', defined by different rhodopsin pairs expressed in R7 and R8 cells. Similar to the human cone photoreceptors, these ommatidial subtypes are distributed stochastically in the retina. The choice between pale versus yellow ommatidia is made in R7 cells, which then impose their fate onto R8. Here we report that the Drosophila dioxin receptor Spineless is both necessary and sufficient for the formation of the ommatidial mosaic. A short burst of spineless expression at mid-pupation in a large subset of R7 cells precedes rhodopsin expression. In spineless mutants, all R7 and most R8 cells adopt the pale fate, whereas overexpression of spineless is sufficient to induce the yellow R7 fate. Therefore, this study suggests that the entire retinal mosaic required for colour vision is defined by the stochastic expression of a single transcription factor, Spineless. PMID:16525464

  4. Suitability of School Textbooks for 5 to 7 Year Old Children with Colour Vision Deficiencies

    ERIC Educational Resources Information Center

    Torrents, Aurora; Bofill, Francesc; Cardona, Genis

    2011-01-01

    Purpose: The aim of the present study was to determine, through colorimetric analysis, whether school textbooks for children aged 5 to 7 years contained tasks requiring normal colour vision discrimination for their resolution. In addition, the performance of a group of observers with diverse colour vision deficiencies was evaluated while…

  5. The fiddler crab Uca mjoebergi uses colour vision in mate choice

    PubMed Central

    Detto, Tanya

    2007-01-01

    Although the role of colour in mate choice is well known, few tests of colour vision have been based on mating behaviour. Females of the fiddler crab Uca mjoebergi have recently been shown to use claw coloration to recognize conspecific males. In this study I demonstrate that the females use colour vision for this task; preferentially approaching yellow claws over grey claws regardless of their intensity while failing to discriminate between yellow claws differing in intensity. This is one of only a handful of studies confirming the involvement of colour vision in mate choice and the first conclusive evidence in fiddler crabs. PMID:17848366

  6. Research the mobile phone operation interfaces for vision-impairment.

    PubMed

    Yao, Yen-Ting; Leung, Cherng-Yee

    2012-01-01

    Due to the vision-impaired users commonly having difficulty with mobile-phone function operations and adaption any manufacturer's user interface design, the goals for this research are established for evaluating how to improve for them the function operation convenience and user interfaces of either mobile phones or electronic appliances in the market currently. After applying collecting back 30 effective questionnaires from 30 vision-impairment, the comments have been concluded from this research include: (1) All mobile phone manufactures commonly ignorant of the vision-impairment difficulty with operating mobile phone user interfaces; (2) The vision-impairment preferential with audio alert signals; (3) The vision-impairment incapable of mobile-phone procurement independently unless with assistance from others; (4) Preferential with adding touch-usage interface design by the vision-impairment; in contrast with the least requirement for such functions as braille, enlarging keystroke size and diversifying-function control panel. With exploring the vision-impairment's necessary improvements and obstacles for mobile phone interface operation, this research is established with goals for offering reference possibly applied in electronic appliance design and . Hopefully, the analysis results of this research could be used as data references for designing electronic and high-tech products and promoting more usage convenience for those vision-impaired. PMID:22317456

  7. A VISION SYSTEM FOR PROVIDING THE BLIND WITH 3D COLOUR PERCEPTION OF THE ENVIRONMENT

    E-print Network

    Ward, Koren

    are attempting to develop bionic vision for the blind, see [1], [2] and [3]. This is comprised of artificial electrodes. The only commercially available artificial vision implant, at present, is the Dobelle Implant [4A VISION SYSTEM FOR PROVIDING THE BLIND WITH 3D COLOUR PERCEPTION OF THE ENVIRONMENT SIMON MEERS

  8. Red-green color vision impairment in Duchenne muscular dystrophy.

    PubMed

    Costa, Marcelo Fernandes; Oliveira, Andre Gustavo Fernandes; Feitosa-Santana, Claudia; Zatz, Mayana; Ventura, Dora Fix

    2007-06-01

    The present study evaluated the color vision of 44 patients with Duchenne muscular dystrophy (DMD) (mean age 14.8 years; SD 4.9) who were submitted to a battery of four different color tests: Cambridge Colour Test (CCT), Neitz Anomaloscope, Ishihara, and American Optical Hardy-Rand-Rittler (AO H-R-R). Patients were divided into two groups according to the region of deletion in the dystrophin gene: upstream of exon 30 (n=12) and downstream of exon 30 (n=32). The control group was composed of 70 age-matched healthy male subjects with no ophthalmological complaints. Of the patients with DMD, 47% (21/44) had a red-green color vision defect in the CCT, confirmed by the Neitz Anomaloscope with statistical agreement (P<.001). The Ishihara and the AO H-R-R had a lower capacity to detect color defects--5% and 7%, respectively, with no statistical similarity between the results of these two tests nor between CCT and Anomaloscope results (P>.05). Of the patients with deletion downstream of exon 30, 66% had a red-green color defect. No color defect was found in the patients with deletion upstream of exon 30. A negative correlation between the color thresholds and age was found for the controls and patients with DMD, suggesting a nonprogressive color defect. The percentage (66%) of patients with a red-green defect was significantly higher than the expected <10% for the normal male population (P<.001). In contrast, patients with DMD with deletion upstream of exon 30 had normal color vision. This color defect might be partially explained by a retina impairment related to dystrophin isoform Dp260. PMID:17503325

  9. Essay/Book review to appear in The Gerontologist VISION IMPAIRMENT AND REHABILITATION

    E-print Network

    Sekuler, Robert

    Essay/Book review to appear in The Gerontologist VISION IMPAIRMENT AND REHABILITATION: TAKING STOCK and Frank J. Whittington. AFB Press, New York, 285 pp., $32.95 (paper). Vision Rehabilitation: Assessment). The Lighthouse Handbook on Vision Impairment and Vision Rehabilitation, Volume I, Vision Impairment, and Volume

  10. Qualitative color vision impairment in toluene-exposed workers

    Microsoft Academic Search

    M. Zavali?; Z. Mandi?; R. Turk; A. Bogadi-Šare; D. Plavec; L. J. Skender

    1998-01-01

    Objective?: The aim of this study was to evaluate whether toluene, like many other organic solvents and solvent mixtures, could impair\\u000a color vision. Subjects and methods?: We investigated color vision impairment in three groups of workers, two groups occupationally exposed to toluene and a\\u000a nonexposed group. The first exposed group, group E1, comprised 41 workers (median value of toluene in

  11. Avian colour vision: Effects of variation in receptor sensitivity and noise data on model predictions as compared to behavioural results

    Microsoft Academic Search

    Olle Lind; Almut Kelber

    2009-01-01

    Colour vision models require measurement of receptor noise and the absorbance of visual pigments, oil droplets, and ocular media. We have studied how variation in these parameters influences colour matching, spectral sensitivity, and colour discrimination predictions in four bird species. While colour match predictions are sensitive to variation in visual pigment and oil droplet absorbance data, discrimination predictions are mostly

  12. Project VISION: Visually Impaired Students and Internet Opportunities Now.

    ERIC Educational Resources Information Center

    Kapperman, Gaylen; And Others

    Project VISION (Visually Impaired Students and Internet Opportunities Now) was a 2-year effort to develop and test methods and strategies by which blind and visually impaired students can use assistive technology to gain access to the resources found on the Internet. The project produced a manual and a videotape. Nine students were provided with…

  13. IMAGE ENHANCEMENT FOR IMPAIRED VISION: THE CHALLENGE OF EVALUATION

    PubMed Central

    PELI, ELI; WOODS, RUSSELL L

    2009-01-01

    With the aging of the population, the prevalence of eye diseases and thus of vision impairment is increasing. The TV watching habits of people with vision impairments are comparable to normally sighted people1, however their vision loss prevents them from fully benefiting from this medium. For over 20 years we have been developing video image-enhancement techniques designed to assist people with visual impairments, particularly those due to central retinal vision loss. A major difficulty in this endeavor is the lack of evaluation techniques to assess and compare the effectiveness of various enhancement methods. This paper reviews our approaches to image enhancement and the results we have obtained, with special emphasis on the difficulties encountered in the evaluation of the benefits of enhancement and the solutions we have developed to date. PMID:20161188

  14. Vision impairment in the Pacific region

    PubMed Central

    Keeffe, J E; Konyama, K; Taylor, H R

    2002-01-01

    The Western Pacific region is one of great diversity, containing the most populous country, China, and many small Pacific island countries. This review describes the prevalence of blindness and vision loss, illustrates the changing trends in the important causes of vision loss and blindness, and the stages of development of the delivery of eye care services across this region. PMID:12034678

  15. Beyond W3C: TruVision--Enhanced Online Learning for People Blind or Vision Impaired.

    ERIC Educational Resources Information Center

    Bate, Frank; Oliver, Ron

    This paper describes the design and development of TruVision, an online learning environment designed to enable blind and vision impaired students to develop skills and expertise in elementary and advanced information processing strategies to enable them to seek full-time employment within industry in such positions as administrative assistants,…

  16. Global cost of correcting vision impairment from uncorrected refractive error

    PubMed Central

    Fricke, TR; Wilson, DA; Schlenther, G; Naidoo, KS; Resnikoff, S; Frick, KD

    2012-01-01

    Abstract Objective To estimate the global cost of establishing and operating the educational and refractive care facilities required to provide care to all individuals who currently have vision impairment resulting from uncorrected refractive error (URE). Methods The global cost of correcting URE was estimated using data on the population, the prevalence of URE and the number of existing refractive care practitioners in individual countries, the cost of establishing and operating educational programmes for practitioners and the cost of establishing and operating refractive care facilities. The assumptions made ensured that costs were not underestimated and an upper limit to the costs was derived using the most expensive extreme for each assumption. Findings There were an estimated 158 million cases of distance vision impairment and 544 million cases of near vision impairment caused by URE worldwide in 2007. Approximately 47?000 additional full-time functional clinical refractionists and 18?000 ophthalmic dispensers would be required to provide refractive care services for these individuals. The global cost of educating the additional personnel and of establishing, maintaining and operating the refractive care facilities needed was estimated to be around 20?000 million United States dollars (US$) and the upper-limit cost was US$ 28?000 million. The estimated loss in global gross domestic product due to distance vision impairment caused by URE was US$ 202?000 million annually. Conclusion The cost of establishing and operating the educational and refractive care facilities required to deal with vision impairment resulting from URE was a small proportion of the global loss in productivity associated with that vision impairment. PMID:23109740

  17. Theory and practice of colour vision testing: A review. Part 2

    PubMed Central

    Lakowski, R.

    1969-01-01

    Lakowski, R. (1969).Brit. J. industr. Med.,26, 265-288. Theory and practice of colour vision testing: A review. Part 2. The more modern tests of colour confusion, hue discrimination, metamerism, and special aptitudes measure a wide variety of attributes. Norms, including variations among normal as well as among defective observers, are given for each test, along with any other information we require to understand them. Finally there is the problem of choice, and factors influencing it, of which tests should be used in different circumstances. Some advice is given on the most useful combinations of tests. PMID:4899666

  18. Dichromatic colour vision in wallabies as characterised by three behavioural paradigms.

    PubMed

    Ebeling, Wiebke; Hemmi, Jan M

    2014-01-01

    Despite lacking genetic evidence of a third cone opsin in the retina of any Australian marsupial, most species tested so far appear to be trichromatic. In the light of this, we have re-examined colour vision of the tammar wallaby which had previously been identified as a dichromat. Three different psychophysical tests, based on an operant conditioning paradigm, were used to confirm that colour perception in the wallaby can be predicted and conclusively explained by the existence of only two cone types. Firstly, colour-mixing experiments revealed a Confusion Point between the three primary colours of a LCD monitor that can be predicted by the cone excitation ratio of the short- and middle-wavelength sensitive cones. Secondly, the wavelength discrimination ability in the wallaby, when tested with monochromatic stimuli, was found to be limited to a narrow range between 440 nm and 500 nm. Lastly, an experiment designed to test the wallaby's ability to discriminate monochromatic lights from a white light provided clear evidence for a Neutral Point around 485 nm where discrimination consistently failed. Relative colour discrimination seemed clearly preferred but it was possible to train a wallaby to perform absolute colour discriminations. The results confirm the tammar wallaby as a dichromat, and so far the only behaviourally confirmed dichromat among the Australian marsupials. PMID:24489742

  19. Advanced IT Education for the Vision Impaired via e-Learning

    ERIC Educational Resources Information Center

    Armstrong, Helen L.

    2009-01-01

    Lack of accessibility in the design of e-learning courses continues to hinder students with vision impairment. E-learning materials are predominantly vision-centric, incorporating images, animation, and interactive media, and as a result students with acute vision impairment do not have equal opportunity to gain tertiary qualifications or skills…

  20. The Reliability of the CVI Range: A Functional Vision Assessment for Children with Cortical Visual Impairment

    ERIC Educational Resources Information Center

    Newcomb, Sandra

    2010-01-01

    Children who are identified as visually impaired frequently have a functional vision assessment as one way to determine how their visual impairment affects their educational performance. The CVI Range is a functional vision assessment for children with cortical visual impairment. The purpose of the study presented here was to examine the…

  1. Prevalence of Adult Vision Impairment and Age-Related Eye Diseases in America

    MedlinePLUS

    ... Education Programs Training and Jobs Prevalence of Adult Vision Impairment and Age-Related Eye Diseases in America ... U.S. Census populations) Estimated Number of Cases by Vision Problem Age ? 40 Total Population ? 40 14,186, ...

  2. Spotting fruit versus picking fruit as the selective advantage of human colour vision

    PubMed Central

    Bompas, Aline; Kendall, Grace; Sumner, Petroc

    2013-01-01

    The spatiochromatic properties of the red–green dimension of human colour vision appear to be optimized for picking fruit in leaves at about arms' reach. However, other evidence suggests that the task of spotting fruit from a distance might be more important. This discrepancy may arise because the task a system (e.g. human trichromacy) is best at is not necessarily the same task where the largest advantage occurs over the evolutionary alternatives (dichromacy or anomalous trichromacy). We tested human dichromats, anomalous trichromats and “normal” trichromats in a naturalistic visual search task in which they had to find fruit pieces in a bush at 1, 4, 8 or 12 m viewing distance. We found that the largest advantage (in terms of either performance ratio or performance difference) of normal trichromacy over both types of colour deficiency was for the largest viewing distance. We infer that in the evolution of human colour vision, spotting fruit from a distance was a more important selective advantage than picking fruit at arms' reach. PMID:23755352

  3. Photoreceptor sectral sensitivities in terrestrial animals: adaptations for luminance and colour vision

    PubMed Central

    Osorio, D; Vorobyev, M

    2005-01-01

    This review outlines how eyes of terrestrial vertebrates and insects meet the competing requirements of coding both spatial and spectral information. There is no unique solution to this problem. Thus, mammals and honeybees use their long-wavelength receptors for both achromatic (luminance) and colour vision, whereas flies and birds probably use separate sets of photoreceptors for the two purposes. In particular, we look at spectral tuning and diversification among ‘long-wavelength’ receptors (sensitivity maxima at greater than 500?nm), which play a primary role in luminance vision. Data on spectral sensitivities and phylogeny of visual photopigments can be incorporated into theoretical models to suggest how eyes are adapted to coding natural stimuli. Models indicate, for example, that animal colour vision—involving five or fewer broadly tuned receptors—is well matched to most natural spectra. We can also predict that the particular objects of interest and signal-to-noise ratios will affect the optimal eye design. Nonetheless, it remains difficult to account for the adaptive significance of features such as co-expression of photopigments in single receptors, variation in spectral sensitivities of mammalian L-cone pigments and the diversification of long-wavelength receptors that has occurred in several terrestrial lineages. PMID:16096084

  4. The Impact of Residual Vision in Spatial Skills of Individuals with Visual Impairments

    ERIC Educational Resources Information Center

    Papadopoulos, Konstantinos; Koustriava, Eleni; Kartasidou, Lefkothea

    2011-01-01

    Loss of vision is believed to have a great impact on the acquisition of spatial knowledge. The aims of the present study are to examine the performance of individuals with visual impairments on spatial tasks and the impact of residual vision on processing these tasks. In all, 28 individuals with visual impairments--blindness or low…

  5. The Perspectives of Singapore Secondary School Students with Vision Impairments towards Their Inclusion in Mainstream Education

    ERIC Educational Resources Information Center

    West, John; Houghton, Stephen; Taylor, Myra; Ling, Phua Kia

    2004-01-01

    Students with vision impairments in Singapore are educated in segregated settings from an early age. On completing primary school these students continue their education in mainstream secondary school settings. This transition requires considerable adjustment on the part of students with vision impairments. The present research explored the social…

  6. The Potential Impact of Undiagnosed Vision Impairment on Reading Development in the Early Years of School

    ERIC Educational Resources Information Center

    Thurston, Allen

    2014-01-01

    This article presents a critical review of the literature surrounding the potential impact of undiagnosed and untreated vision impairment on reading development in the early years of primary school. Despite pre-school screening programmes, it is still possible for children to enter school with undiagnosed, uncorrected vision impairments. This can…

  7. VISION PROBLEMS IN THE U.S.-PREVALENCE OF ADULT VISION IMPAIRMENT AND AGE-RELATED EYE DISEASES IN AMERICA

    EPA Science Inventory

    Leading causes of vision impairment and blindness in the United States. Diabetic retinopathy? Age-related macular degeneration (AMD)? Cataract? Glaucoma? The Vision Problems in the U.S. study was the result of a 2001 consensus meeting, convened by the National Eye Institute and ...

  8. Diurnal variations of acute mountain sickness, colour vision, and plasma cortisol and ACTH at high altitude.

    PubMed

    Richalet, J P; Rutgers, V; Bouchet, P; Rymer, J C; Kéromès, A; Duval-Arnould, G; Rathat, C

    1989-02-01

    Time dependence of colour vision in the green/red axis, signs of acute mountain sickness (AMS), and plasma cortisol and ACTH concentrations were studied in eight sea-level male natives exposed 79 h to altitude hypoxia at 4,350 m. Colour vision (CV) was explored every 2 h from 08:00 to 20:00 hours by means of two portable anomaloscopes, one derived from Essilor CHROMOTEST and the other from the OSCAR. Significant diurnal variations in CV were found using both anomaloscopes, major alterations in green relative to red sensitivity being seen in the early morning. AMS scores also showed remarkable diurnal variations, parallel to those of plasma cortisol and CV, with maximum values observed at 08:00 hours. Cortisol diurnal rhythm was maintained in hypoxia, with mean concentrations higher than in normoxia. ACTH followed the same trend, but variations were not significant. Significant correlations were found between instant values of CV, cortisol, and AMS score, but no causal relationship between these variables can be ascertained. PMID:2539079

  9. A new colour vision arrangement test to detect functional changes in diabetic macular oedema

    PubMed Central

    Maar, N; Tittl, M; Stur, M; Zajic, B; Reitner, A

    2001-01-01

    AIM—A study was undertaken to investigate the correlation between colour discrimination tests and the presence of macular oedema in patients with type I diabetes to find a sensitive diagnostic tool for the detection of early functional changes.?METHODS—The study was performed in 39 type I diabetic patients, 10 with and 29 without macular oedema. The examination included biomicroscopy, fundus photography of the macula, videofluorescein angiography, the LogMAR visual acuity chart, Farnsworth-Lanthony desaturated D-15 test, and the new Mollon-Reffin "Minimalist" test for colour vision deficiencies version 6.0.?RESULTS—A highly significant correlation was found between the tritan value of the Mollon test and the presence of clinically significant macular oedema (p<0.0015), with a high sensitivity (88.9%) and specificity (93.3%). The DD-15 test was not significant (p=0.345) and showed low sensitivity for the presence of macular oedema (36%). All variables concerning the grading of macular oedema showed a highly significant association with the tritan values of the Mollon test (p<0.0001).?CONCLUSION—The results suggest that the Mollon-Reffin "Minimalist" test version 6.0 is the best colour discrimination test for detecting macular oedema, with higher specificity and sensitivity than the other methods used in the study.?? PMID:11133711

  10. Computer vision-based analysis of foods: a non-destructive colour measurement tool to monitor quality and safety.

    PubMed

    Mogol, Burçe Ataç; Gökmen, Vural

    2014-05-01

    Computer vision-based image analysis has been widely used in food industry to monitor food quality. It allows low-cost and non-contact measurements of colour to be performed. In this paper, two computer vision-based image analysis approaches are discussed to extract mean colour or featured colour information from the digital images of foods. These types of information may be of particular importance as colour indicates certain chemical changes or physical properties in foods. As exemplified here, the mean CIE a* value or browning ratio determined by means of computer vision-based image analysis algorithms can be correlated with acrylamide content of potato chips or cookies. Or, porosity index as an important physical property of breadcrumb can be calculated easily. In this respect, computer vision-based image analysis provides a useful tool for automatic inspection of food products in a manufacturing line, and it can be actively involved in the decision-making process where rapid quality/safety evaluation is needed. PMID:24288215

  11. Effects of hearing and vision impairments on the Montreal Cognitive Assessment.

    PubMed

    Dupuis, Kate; Pichora-Fuller, M Kathleen; Chasteen, Alison L; Marchuk, Veronica; Singh, Gurjit; Smith, Sherri L

    2015-07-01

    Many standardized measures of cognition include items that must be seen or heard. Nevertheless, it is not uncommon to overlook the possible effects of sensory impairment(s) on test scores. In the current study, we investigated whether sensory impairments could affect performance on a widely used screening tool, the Montreal Cognitive Assessment (MoCA). Three hundred and one older adults (mean age = 71 years) completed the MoCA and also hearing and vision tests. Half of the participants had normal hearing and vision, 38% impaired hearing, 5% impaired vision, and 7% had dual-sensory impairment. More participants with normal sensory acuity passed the MoCA compared to those with sensory loss, even after modifying scores to adjust for sensory factors. The results suggest that cognitive abilities may be underestimated if sensory problems are not considered and that people with sensory loss are at greater risk of cognitive decline. PMID:25325767

  12. Exercise and Drinking May Play a Role in Vision Impairment Risk

    MedlinePLUS

    ... Exercise and Drinking May Play a Role in Vision Impairment Risk Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ...

  13. Remote and local delivery of cisco education for the vision-impaired

    Microsoft Academic Search

    Helen Armstrong; Iain Murray

    2007-01-01

    Vision-impaired students face tremendous obstacles in their quest to access learning materials delivered in web-based and other electronic formats. The predominance of visual prompts, use of flash and animation and the inability of screen reading applications to interpret images all contribute to make much of the current e-learning materials associated with computing studies inaccessible by blind or vision-impaired students. This

  14. Facilitating the Inclusion of Children with Vision Impairment: Perspectives of Itinerant Support Teachers

    ERIC Educational Resources Information Center

    Morris, Christine; Sharma, Umesh

    2011-01-01

    Children with vision impairment (VI) and blindness are largely educated in mainstream schools in Australia. Specialist itinerant support teachers--vision (ISTVs) travel from school to school to facilitate the education of these children. The purposes of this study were to examine the barriers that ISTVs face in this role, and to identify…

  15. Education of Children with Vision Impairments in the Sultanate of Oman.

    ERIC Educational Resources Information Center

    Hadidi, Muna S. Z.

    1998-01-01

    Describes the prevalence and patterns of vision impairment in the Sultanate of Oman. Reviews the types of special education and rehabilitation services offered and future priorities. Concludes that, although at present, few visually impaired children are receiving services, a special education system is evolving into a community-based approach to…

  16. The Effect of Gender and Level of Vision on the Physical Activity Level of Children and Adolescents with Visual Impairment

    ERIC Educational Resources Information Center

    Aslan, Ummuhan Bas; Calik, Bilge Basakci; Kitis, Ali

    2012-01-01

    This study was planned in order to determine physical activity levels of visually impaired children and adolescents and to investigate the effect of gender and level of vision on physical activity level in visually impaired children and adolescents. A total of 30 visually impaired children and adolescents (16 low vision and 14 blind) aged between…

  17. Impact of Pediatric Vision Impairment on Daily Life: Results of Focus Groups

    PubMed Central

    DeCarlo, Dawn K.; McGwin, Gerald; Bixler, Martha L.; Wallander, Jan; Owsley, Cynthia

    2012-01-01

    Purpose To identify through focus groups of visually impaired children and their parents, relevant content for a vision-targeted health-related quality of life questionnaire designed for children ages 6-12. Methods Six focus groups of children with vision impairment ages 6 -12 and six focus groups of their parents were conducted by trained facilitators using a guided script. Sessions were recorded, transcribed and coded per a standardized protocol for content analysis. Comments were placed in thematic categories and each coded as positive, negative or neutral. Results Twenty-four children (mean age 9.4 years) with vision impairment from a variety of causes and 23 parents participated. The child focus groups generated 1,163 comments, of which 52% (n=599) were negative, 12% (n=138) were neutral and 37% (n=426) were positive. The three most common topical areas among children were: glasses and adaptive equipment (18%), psychosocial (14%) and school (14%). The parent focus groups generated 1,952 comments of which 46% (n=895) were negative, 16% (n=323) were neutral and 38% (n=734) were positive. The three most common topical areas among parents were: school (21%), expectations or frustrations (14%) and psychosocial (13%). Conclusions Pediatric vision impairment has significant effects on health related quality of life, as reported by children with vision impairment and their parents in their own words. These findings will provide the content to guide construction of a survey instrument to assess vision-specific, health-related quality of life in children with vision impairment. PMID:22863790

  18. Impairment of color vision in aircraft maintenance workers

    Microsoft Academic Search

    Maya Guest; Catherine D’Este; John Attia; May Boggess; Anthony Brown; Meredith Tavener; Richard Gibson; Ian Gardner; Warren Harrex; James Ross

    Purpose  The purpose of the study was to examine possible persisting effects to color vision in a group from the Royal Australian Air\\u000a Force who had exposure to formulations containing neurotoxins during F-111 fuel tank maintenance, relative to two contemporaneous\\u000a comparison groups.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Color vision was tested in 512 exposed personnel, 458 technical-trade comparisons, and 330 non-technical comparisons using\\u000a the Ishihara test

  19. Occupational therapy and the person with diabetes and vision impairment.

    PubMed

    Cate, Y; Baker, S S; Gilbert, M P

    1995-10-01

    Diabetes affects 5.2% of the population; many of those persons experience loss of vision as one complication of the disease. Occupational therapists are treating these persons, often for other resulting complications (such as stroke or amputations), or are being asked to adapt techniques or equipment (such as insulin-drawing devices) needed for diabetes management. Because no guidelines exist for occupational therapy with persons with diabetes or vision loss or both, occupational therapists may be unsure of appropriate treatment approaches. Among the approaches described in the occupational therapy literature, common ones include collaboration with other professionals and incorporation of one or more aspects of the diabetes regimen into the person's life-style. When addressing persons who have both diabetes and vision loss, therapists consider their own knowledge base as well as the persons' needs in managing their diabetes. Treatment ideas include enhancing the visual environment or incorporating tactile and auditory feedback with self-management tasks such as testing blood glucose levels. Collaboration with and referral to diabetes and low-vision professionals are adjuncts to therapy and ensure a comprehensive and ongoing diabetes management program. PMID:8572050

  20. Test Anxiety Research: Students with Vision Impairments and Students with Mild Intellectual Disabilities

    ERIC Educational Resources Information Center

    Datta, Poulomee

    2014-01-01

    There is an absence of research on test anxiety in students with disabilities although such testing is taken for granted among students without disabilities. This study investigated the test anxiety of the students in each of the two disability groups, those with vision impairments and those with intellectual disabilities who are placed in…

  1. Benign Visual Hallucinations, or "Phantom Vision" in Visually Impaired and Blind Persons.

    ERIC Educational Resources Information Center

    Needham, W. E.; Taylor, R. E.

    1992-01-01

    Benign visual hallucinations ("phantom vision") were examined in 2 studies, involving a total of 443 adventitiously blinded and sight-impaired veterans. In one study, unusual visual events were reported by 38.7 percent, with 30.6 percent reporting complex hallucinations. Causes of the hallucinations and their treatment are discussed. (Author/JDD)

  2. Students with Low Vision Describe Their Visual Impairments and Visual Functioning

    ERIC Educational Resources Information Center

    Guerette, Amy R.; Lewis, Sandra; Mattingly, Cameron

    2011-01-01

    In the study reported here, the responses to a survey that was designed to determine the knowledge of their visual impairment of 51 students with low vision were analyzed. Although the students described their visual weaknesses and strengths, they had limited knowledge of, and difficulty communicating about, the medical aspects of their…

  3. An Overview of a UK Paediatric Visual Impaired Population and Low Vision Aid Provision

    ERIC Educational Resources Information Center

    Theodorou, Nana; Shipman, Tracey

    2013-01-01

    A retrospective study was carried out to evaluate the paediatric visual impaired population attending the Low Vision Clinic at Sheffield Teaching Hospitals NHS Foundation Trust, over a period of 14 years. Data were collected and analysed for children less than 17 years for prevalence, demographics, registration status, aetiologies, and types of…

  4. The "Inclusion" of Students with Vision Impairments: Generational Perspectives in Australia

    ERIC Educational Resources Information Center

    Whitburn, Ben

    2014-01-01

    In this paper I draw upon findings of a recent qualitative project conducted in Queensland, Australia in which all actors--the researcher and 5 participants aged 13-17 years--were linked together by our shared experiences of being students with impaired vision (VI) and who were educated in inclusive secondary schools in Australia during the last…

  5. Audio from Orbit: The Future of Libraries for Individuals Who Are Blind or Vision Impaired

    ERIC Educational Resources Information Center

    Steer, Michael; Cheetham, Leonie

    2005-01-01

    Free library service is a component of the foundations of democracy, citizenship, economic and social development, scholarship and education, in progressive societies. The evolution of libraries for people who are blind or vision impaired is briefly discussed and an innovative project, a talking book and daily newspaper delivery system that…

  6. Variations of colour vision in a New World primate can be explained by polymorphism of retinal photopigments.

    PubMed

    Mollon, J D; Bowmaker, J K; Jacobs, G H

    1984-09-22

    The squirrel monkey (Saimiri sciureus) exhibits a polymorphism of colour vision: some animals are dichromatic, some trichromatic, and within each of these classes there are subtypes that resemble the protan and deutan variants of human colour vision. For each of ten individual monkeys we have obtained (i) behavioural measurements of colour vision and (ii) microspectrophotometric measurements of retinal photopigments. The behavioural tests, carried out in Santa Barbara, included wavelength discrimination, Rayleigh matches, and increment sensitivity at 540 and 640 nm. The microspectrophotometric measurements were made in London, using samples of fresh retinal tissue and a modified Liebman microspectrophotometer: the absorbance spectra for single retinal cells were obtained by passing a monochromatic measuring beam through the outer segments of individual rods and cones. The two types of data, behavioural and microspectrophotometric, were obtained independently and were handed to a third party before being interchanged between experimenters. From all ten animals, a rod pigment was recorded with lambda max (wavelength of peak absorbance) close to 500 nm. In several animals, receptors were found that contained a short-wave pigment (mean lambda max = 433.5 nm): these violet-sensitive receptors were rare, as in man and other primate species. In the middle- to long-wave part of the spectrum, there appear to be at least three possible Saimiri photopigments (with lambda max values at about 537,550 and 565 nm) and individual animals draw either one or two pigments from this set, giving dichromatic or trichromatic colour vision. Thus, those animals that behaviourally resembled human protanopes exhibited only one pigment in the red-green range, with lambda max = 537 nm; other behaviourally dichromatic animals had single pigments lying at longer wavelengths and these were the animals that behaviourally had higher sensitivity to long wavelengths. Four of the monkeys were behaviourally judged to be trichromatic. None of the latter animals exhibited the two widely separated pigments (close to 535 and 567 nm) that are found in the middle- and long-wave cones of macaque monkeys.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:6149558

  7. Seroepidemiology of Toxocara Infection in Patients With Vision Impairment and Blindness in Durango, Mexico

    PubMed Central

    Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco

    2015-01-01

    Background Toxocara infection is a cause of vision impairment and blindness. We aimed to determine the seroprevalence and correlates of Toxocara infection in patients suffering from vision impairment and blindness in Durango City, Mexico. Methods Through a cross-sectional seroprevalence study, 204 patients with vision impairment and 19 blind patients were studied for the presence of anti-Toxocara IgG antibodies in Durango City, Mexico. Seroprevalence association with socio-demographic, housing, clinical, and behavioral characteristics of participants was also investigated. Results Five (2.5%) of the 204 patients with vision impairment, and none of the 19 patients with blindness were positive for anti-Toxocara IgG antibodies. In total, five of the 223 (2.2%) patients were positive for anti-Toxocara IgG antibodies. Seropositivity to Toxocara was not associated with age, sex, educational level, socio-economic status, presence of underlying diseases or behavioral characteristics of the patients. In contrast, multivariate analysis showed that Toxocara seropositivity was associated with living in a house with soil floor (odds ratio (OR) = 11.14; 95% confidence interval (CI): 1.57 - 78.74; P = 0.01). Conclusions This is the first report of Toxocara exposure in patients with vision impairment and blindness in Mexico, and of an association of Toxocara exposure with living in a house with soil floors. Results suggest a low Toxocara exposure in these patients in Durango, Mexico. The risk factor associated with Toxocara exposure identified in this study warrants for further investigation. PMID:25584103

  8. Sensory impairments in community health care: a descriptive study of hearing and vision among elderly Norwegians living at home

    PubMed Central

    Haanes, Gro Gade; Kirkevold, Marit; Horgen, Gunnar; Hofoss, Dag; Eilertsen, Grethe

    2014-01-01

    Background Hearing and vision impairments increase with age and are common risk factors for functional decline reduced social participation and withdrawal. Objective Describe the hearing and vision of home care patients older than 80 years. Methods Ninety-three older adults (80+ years) receiving home care were screened for hearing and vision in their homes. Data were collected using a HEINE Mini 3000® Otoscope to examine the eardrum and presence of earwax, an Entomed SA201-IV portable pure-tone audiometer to measure the pure-tone average (PTAV), a logarithm of the minimum angle of resolution chart to measure visual acuity (VA), and the Combined Serious Sensory Impairment interview guide. Results Slight and moderate hearing impairments were found in 41% and 47% of the population, respectively (mean PTAV =40.4 dB for the better ear), and 40% and 56% had impaired and slightly impaired vision, respectively (mean VA =0.45 for the better eye). The participants’ self-assessments of hearing and vision were only weakly correlated with PTAV and VA values. The visual function was significantly worse in men than in women (P=0.033). Difficulty in performing instrumental activities of daily living because of hearing and vision impairments was experienced by 17% of the participants, whereas 76% experienced no difficulties. When many people were present, 72% of the participants found it difficult to understand speech. Nearly 30% found it tiring to read, and 41% could not read very small print. Conclusion The patients’ self-assessments of their hearing and vision did not correlate strongly with their VA and PTAV scores. Asking the elderly about their overall hearing and vision ability is not sufficient for detecting sensory impairment, and asking more specific questions about what they could not hear and see was not an adequate indicator of the patients’ hearing and vision problems. To detect hearing and vision impairments among elderly home care patients, standardized measurements of their hearing and vision are necessary. PMID:24920916

  9. Space Vision: Making Astronomy Accessible to Visually Impaired Students

    NASA Astrophysics Data System (ADS)

    Ries, J. G.; Baguio, M. R.; Jurgens, T. D.; Pruett, K. M.

    2004-05-01

    Astronomy, with good reason, is thought of as a visual science. Spectacular images of deep space objects or other worlds of our solar system inspire public interest in Astronomy. People encounter news about the universe during their daily life. Developing concepts about celestial objects presents an extra challenge of abstraction for people with visual impairments. The Texas Space Grant Consortium with educators at the Texas School for the Blind and Visually Impaired have developed a 2 day workshop to be held in April 2004 to help students with visual impairments understand these concepts. Hands-on activities and experiments will emphasize non-visual senses. For example, students will learn about: - Constellations as historical ways of finding one's way across the sky. - The size and structure of the Solar System by building a scale model on a running track. They will also: - Plan a planetary exploration mission. - Explore wave phenomenon using heat and sound waves. In preparation for the workshop we worked with teens involved in the countywide 4-H Teens Leading with Character (TLC) program to create the tactile materials necessary for the activities. The teens attended solar system education training so they would have the skills necessary to make the tactile displays to be used during the workshop. The results and evaluation of the workshop will be presented at the meeting. Touch the Universe: A NASA Braille Book of Astronomy inspired this workshop, and it is supported by HST Grant HST-ED-90255.01-A.

  10. The Influence of Manifest Strabismus and Stereoscopic Vision on Non-Verbal Abilities of Visually Impaired Children

    ERIC Educational Resources Information Center

    Gligorovic, Milica; Vucinic, Vesna; Eskirovic, Branka; Jablan, Branka

    2011-01-01

    This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

  11. Colour Perception in ADHD

    ERIC Educational Resources Information Center

    Banaschewski, Tobias; Ruppert, Sinje; Tannock, Rosemary; Albrecht, Bjorn; Becker, Andreas; Uebel, Henrik; Sergeant, Joseph A.; Rothenberger, Aribert

    2006-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is associated with unexplained impairments on speeded naming of coloured stimuli. These deficits may reflect hypofunctioning retinal dopaminergic mechanisms impairing particularly blue-yellow colour discrimination. Colour perception and rapid colour naming ability were investigated in 14 children…

  12. Development of a quantitative method to measure vision in children with chronic cortical visual impairment.

    PubMed Central

    Good, W V

    2001-01-01

    PURPOSE: Cortical visual impairment (CVI) is the most common cause of bilateral vision impairment in children in Western countries. Better quantitative tools for measuring vision are needed to assess these children, to allow measurement of their visual deficit, and to monitor their response to treatment and rehabilitation. The author performed a series of experiments to assess the use of the sweep visual evoked potential (VEP) as a quantitative tool for measuring vision in CVI. METHODS: The first experiment was a reliability measure (test/retest) of VEP grating acuity thresholds of 23 children with CVI. To validate the VEP procedure, VEP grating acuity was compared to a clinical measure of vision, the Huo scale, and to a psychophysical measure of vision, the Teller Acuity Card procedure. Finally, the sweep VEP was tested as a tool for defining optimal luminance conditions for grating acuity in 13 children with CVI, by measuring grating thresholds under 2 different luminance conditions: 50 and 100 candela per square meter (cd/m2). RESULTS: Retest thresholds were similar to original thresholds (r2 = 0.662; P = .003, 1-tailed t test). Grating VEP measures correlate significantly with the clinical index (r2 = 0.63; P = .00004). Teller acuity measurements are also similar to VEP measures in children (r2 = 0.64; P = .0005) but show lower acuities compared to the VEP for children with particularly low vision. Finally, 3 of 13 children tested under 2 background luminance conditions showed paradoxical improvement in grating threshold with dimmer luminance. CONCLUSIONS: The sweep VEP tool is a reliable and valid means for measuring grating acuity in children with CVI. The tool also shows promise as a means of determining the optimal visual environment for children with CVI. PMID:11797314

  13. The Use of a Tactile-Vision Sensory Substitution System as an Augmentative Tool for Individuals with Visual Impairments

    ERIC Educational Resources Information Center

    Williams, Michael D.; Ray, Christopher T.; Griffith, Jennifer; De l'Aune, William

    2011-01-01

    The promise of novel technological strategies and solutions to assist persons with visual impairments (that is, those who are blind or have low vision) is frequently discussed and held to be widely beneficial in countless applications and daily activities. One such approach involving a tactile-vision sensory substitution modality as a mechanism to…

  14. Self-reported visual impairment and impact on vision-related activities in an elderly Nigerian population: report from the Ibadan Study of Ageing

    PubMed Central

    Bekibele, CO; Gureje, Oye

    2010-01-01

    Background Studies have shown an association between visual impairment and poor overall function. Studies from Africa and developing countries show high prevalence of visual impairment. More information is needed on the community prevalence and impact of visual impairment among elderly Africans. Methods A multi-stage stratified sampling of households was implemented to select persons aged 65 years and over in the south-western and north-central parts of Nigeria. Impairments of distant and near vision were based on subjective self-reports obtained with the use of items derived from the World Health Organization multi-country World Health Survey questionnaire. Impairment was defined as reporting much difficulty to questions on distant and near vision. Disabilities in activities of daily living (ADL) and instrumental activities of daily living (IADL) were evaluated by interview, using standardized scales. Results A total of 2054 subjects 957 (46.6%) males and 1097 (53.4) females responded to the questions on vision. 22% (n=453) of the respondents reported distant vision impairment, and 18% (n=377) reported near vision impairment (not mutually exclusive). 15% (n= 312) however reported impairment for both far and near vision. Impairment of distant vision increased progressively with age (P < 0.01). Persons with self reported near vision impairment had elevated risk of functional disability in several IADLs and ADLs than those with out. Distant vision impairment was less associated with role limitations in both ADLs and IADLs. Conclusion The prevalence of self reported distant visual impairment was high but that for near visual impairment was less than expected in this elderly African population. Impairment of near vision was found to carry with it a higher burden of functional disability than that of distant vision. PMID:18780258

  15. Frugivory and colour vision in Alouatta seniculus, a trichromatic platyrrhine monkey.

    PubMed

    Regan, B C; Julliot, C; Simmen, B; Viénot, F; Charles-Dominique, P; Mollon, J D

    1998-11-01

    It is a long-standing hypothesis that primate trichromacy evolved to help fruit-eating primates find fruits amongst leaves. We measured the reflectance spectra of fruits eaten by a trichromatic primate, Alouatta seniculus, in the rainforest of French Guiana, as well as those of the leaves that form the natural background to fruits. We develop a method of specifying these natural colour signals in a chromaticity diagram appropriate for A. seniculus. By treating the task facing frugivorous monkeys as a signal detection task, we show that the spectral tuning of the L and M cone pigments in A. seniculus is optimal for detecting fruits amongst leaves. PMID:9893844

  16. Vision Impairment

    MedlinePLUS

    ... use . Home Symptom Checkup Injury Checkup Disease Checkup Women's Checkup Pregnancy Checkup Baby Checkup Mens Checkup Stephen J. Schueler, M.D. About Stephen J. Schueler, MD How it Works Testimonials FAQ for Consumers FAQ for Physicians News Advertising Terms of Use Contact Us Site Map How ...

  17. Early Chronic Low-Level Methylmercury Poisoning in Monkeys Impairs Spatial Vision

    NASA Astrophysics Data System (ADS)

    Rice, Deborah C.; Gilbert, Steven G.

    1982-05-01

    Five monkeys were treated from birth with oral doses of mercury as methylmercury (50 micrograms per kilogram of body weight per day); concentrations in the blood peaked at 1.2 to 1.4 parts per million; and declined after weaning from infant formula to a steady level of 0.6 to 0.9 part per million. There were no overt signs of toxicity. When tested between 3 and 4 years of age under conditions of both high and low luminance, treated monkeys exhibited spatial vision that was impaired compared with that of control monkeys.

  18. Device for diagnosis and treatment of impairments on binocular vision and stereopsis

    NASA Astrophysics Data System (ADS)

    Bahn, Jieun; Choi, Yong-Jin; Son, Jung-Young; Kodratiev, N. V.; Elkhov, Victor A.; Ovechkis, Yuri N.; Chung, Chan-sup

    2001-06-01

    Strabismus and amblyopia are two main impairments of our visual system, which are responsible for the loss of stereovision. A device is developed for diagnosis and treatment of strabismus and amblyopia, and for training and developing stereopsis. This device is composed of a liquid crystal glasses (LCG), electronics for driving LCG and synchronizing with an IBM PC, and a special software. The software contains specially designed patterns and graphics for enabling to train and develop stereopsis, and do objective measurement of some stereoscopic vision parameters such as horizontal and vertical phoria, fusion, fixation disparity, and stereoscopic visual threshold.

  19. Crowded visual search in children with normal vision and children with visual impairment.

    PubMed

    Huurneman, Bianca; Cox, Ralf F A; Vlaskamp, Björn N S; Boonstra, F Nienke

    2014-03-01

    This study investigates the influence of oculomotor control, crowding, and attentional factors on visual search in children with normal vision ([NV], n=11), children with visual impairment without nystagmus ([VI-nys], n=11), and children with VI with accompanying nystagmus ([VI+nys], n=26). Exclusion criteria for children with VI were: multiple impairments and visual acuity poorer than 20/400 or better than 20/50. Three search conditions were presented: a row with homogeneous distractors, a matrix with homogeneous distractors, and a matrix with heterogeneous distractors. Element spacing was manipulated in 5 steps from 2 to 32 minutes of arc. Symbols were sized 2 times the threshold acuity to guarantee visibility for the VI groups. During simple row and matrix search with homogeneous distractors children in the VI+nys group were less accurate than children with NV at smaller spacings. Group differences were even more pronounced during matrix search with heterogeneous distractors. Search times were longer in children with VI compared to children with NV. The more extended impairments during serial search reveal greater dependence on oculomotor control during serial compared to parallel search. PMID:24456806

  20. Measuring perceived video quality of MPEG enhancement by people with impaired vision

    PubMed Central

    Fullerton, Matthew; Woods, Russell L.; Vera-Diaz, Fuensanta A.; Peli, Eli

    2007-01-01

    We used a new method to measure the perceived quality of contrast-enhanced motion video. Patients with impaired vision (n = 24) and normally-sighted subjects (n = 6) adjusted the level of MPEG-based enhancement of 8 videos (4 minutes each) drawn from 4 categories. They selected the level of enhancement that provided the preferred view of the videos, using a reducing-step-size staircase procedure. Most patients made consistent selections of the preferred level of enhancement, indicating an appreciation of and a perceived benefit from the MPEG-based enhancement. The selections varied between patients and were correlated with letter contrast sensitivity, but the selections were not affected by training, experience or video category. We measured just noticeable differences (JNDs) directly for videos, and mapped the image manipulation (enhancement in our case) onto an approximately linear perceptual space. These tools and approaches will be of value in other evaluations of the image quality of motion video manipulations. PMID:18059909

  1. Special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. Final rule.

    PubMed

    2014-09-12

    The Department of Veterans Affairs (VA) is issuing a final rule to amend its adjudication regulations regarding special home adaptation grants for members of the Armed Forces and veterans with certain vision impairment. This regulatory amendment is necessary to conform the regulations to changes mandated in the Honoring America's Veterans and Caring for Camp Lejeune Families Act of 2012. PMID:25233534

  2. Visual search performance of patients with vision impairment: Effect of JPEG image enhancement

    PubMed Central

    Luo, Gang; Satgunam, PremNandhini; Peli, Eli

    2012-01-01

    Purpose To measure natural image search performance in patients with central vision impairment. To evaluate the performance effect for a JPEG based image enhancement technique using the visual search task. Method 150 JPEG images were presented on a touch screen monitor in either an enhanced or original version to 19 patients (visual acuity 0.4 to 1.2 logMAR, 6/15 to 6/90, 20/50 to 20/300) and 7 normally sighted controls (visual acuity ?0.12 to 0.1 logMAR, 6/4.5 to 6/7.5, 20/15 to 20/25). Each image fell into one of three categories: faces, indoors, and collections. The enhancement was realized by moderately boosting a mid-range spatial frequency band in the discrete cosine transform (DCT) coefficients of the image luminance component. Participants pointed to an object in a picture that matched a given target displayed at the upper-left corner of the monitor. Search performance was quantified by the percentage of correct responses, the median search time of correct responses, and an “integrated performance” measure – the area under the curve of cumulative correct response rate over search time. Results Patients were able to perform the search tasks but their performance was substantially worse than the controls. Search performances for the 3 image categories were significantly different (p?0.001) for all the participants, with searching for faces being the most difficult. When search time and correct response were analyzed separately, the effect of enhancement led to increase in one measure but decrease in another for many patients. Using the integrated performance, it was found that search performance declined with decrease in acuity (p=0.005). An improvement with enhancement was found mainly for the patients whose acuity ranged from 0.4 to 0.8 logMAR (6/15 to 6/38, 20/50 to 20/125). Enhancement conferred a small but significant improvement in integrated performance for indoor and collection images (p=0.025) in the patients. Conclusion Search performance for natural images can be measured in patients with impaired vision to evaluate the effect of image enhancement. Patients with moderate vision loss might benefit from the moderate level of enhancement used here. PMID:22540926

  3. Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools

    PubMed Central

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-01-01

    Context: Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. Aims: The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. Materials and Methods: A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. ‘Unable to test’ was defined as inappropriate response or uncooperative despite best efforts of the screener. Results: The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes (P < 0.001) but not in Cambridge Crowding Cards, Lang Stereo test II and CVTME. Conclusion: Non verbal or “matching” approaches were found to be more superior in testing visual functions in children with learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities. PMID:24008790

  4. Impairment of color vision among workers exposed to low concentrations of styrene.

    PubMed

    Chia, S E; Jeyaratnam, J; Ong, C N; Ng, T P; Lee, H S

    1994-10-01

    A field study was conducted among 21 male workers exposed to styrene of concentration below 30 ppm in a fiber-reinforced plastic boat manufacturing plant. Twenty-one male workers with similar age groupings, years of education, and social and occupational state served as referents. The mean end-of-shift urinary mandelic acid (MA) and phenylglycoxylic acid (PGA) for the exposed workers were 84 mg/g creatinine and 66 mg/g creatinine, respectively. The Lanthony D-15 Hue Desaturated Panel was used to evaluate color discrimination of the exposed and referent groups. The results of the test were expressed as total color difference score (TCDS). The exposed workers' mean TCDS (a higher score denotes poorer color discrimination ability) was significantly (p < 0.0006) higher than the referents'. Neurobehavioral tests were also conducted, using the World Health Organization's Neurobehavioral Core Test Battery (NCTB). All the results of the NCTB were poorer for the exposed than for the referents. However, significant differences were observed only for Digit Span, Digit Symbol, and Benton Visual Retention tests. These results suggest that low exposure to styrene could affect some psychometric performance and may impair color vision. PMID:7810546

  5. The "voice" has it: screen reader adoption and switching behavior among vision impaired persons in India.

    PubMed

    McCarthy, Ted; Pal, Joyojeet; Cutrell, Edward

    2013-01-01

    We present results from a mixed methods study of screen reader use and switching behavior among people with vision impairments in India. We examine loyalty and experimentation with screen readers and find that the main drivers of adoption for early users differ significantly from the factors that drive continued use by advanced users. We discuss the factor that emerges as one of the strongest stated drivers of early adoption, text-to-speech "voice" quality, particularly a "human-sounding voice" as one of the key features differentiating free/open source products from more expensive proprietary products. While the initial preferences are driven by voice quality, application support becomes more important over time as users speed up their sound settings and become more comfortable with the resultant non-human-sounding speech. We discuss these findings from two theoretical perspectives--first, through the application of the economics of behavior switching, and second, vis-à-vis novice and expert approaches toward new product adoption. We argue that these findings further our understanding of initial user comfort related to assistive technology adoption, and the impact of early technology choices on long-term technology switching behavior. PMID:24620705

  6. The “voice” has it: screen reader adoption and switching behavior among vision impaired persons in India

    PubMed Central

    Pal, Joyojeet; Cutrell, Edward

    2013-01-01

    We present results from a mixed methods study of screen reader use and switching behavior among people with vision impairments in India. We examine loyalty and experimentation with screen readers and find that the main drivers of adoption for early users differ significantly from the factors that drive continued use by advanced users. We discuss the factor that emerges as one of the strongest stated drivers of early adoption, TTS “voice” quality, particularly a “human-sounding voice” as one of the key features differentiating free/open source (FOSS) products from more expensive proprietary products. While the initial preferences are driven by voice quality, application support becomes more important over time as users speed up their sound settings and become more comfortable with the resultant non-human-sounding speech. We discuss these findings from two theoretical perspectives – first, through the application of the economics of behavior switching, and second, vis-à-vis novice and expert approaches toward new product adoption. We argue that these findings further our understanding of initial user comfort related to assistive technology adoption, and the impact of early technology choices on long-term technology switching behavior. PMID:24620705

  7. No rainbow for grey bamboo sharks: evidence for the absence of colour vision in sharks from behavioural discrimination experiments.

    PubMed

    Schluessel, V; Rick, I P; Plischke, K

    2014-11-01

    Despite convincing data collected by microspectrophotometry and molecular biology, rendering sharks colourblind cone monochromats, the question of whether sharks can perceive colour had not been finally resolved in the absence of any behavioural experiments compensating for the confounding factor of brightness. The present study tested the ability of juvenile grey bamboo sharks to perceive colour in an experimental design based on a paradigm established by Karl von Frisch using colours in combination with grey distractor stimuli of equal brightness. Results showed that contrasts but no colours could be discriminated. Blue and yellow stimuli were not distinguished from a grey distractor stimulus of equal brightness but could be distinguished from distractor stimuli of varying brightness. In addition, different grey stimuli were distinguished significantly above chance level from one another. In conclusion, the behavioural results support the previously collected physiological data on bamboo sharks, which mutually show that the grey bamboo shark, like several marine mammals, is a cone monochromate and colourblind. PMID:25245080

  8. Object knowledge modulates colour appearance

    PubMed Central

    Witzel, Christoph; Valkova, Hanna; Hansen, Thorsten; Gegenfurtner, Karl R

    2011-01-01

    We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis. PMID:23145224

  9. "They Think They Know What's Best for Me": An Interpretative Phenomenological Analysis of the Experience of Inclusion and Support in High School for Vision-Impaired Students with Albinism

    ERIC Educational Resources Information Center

    Thurston, Mhairi

    2014-01-01

    The challenges of social inclusion and access to the curriculum facing students with visual impairment in schools are well documented. The refreshed UK Vision Strategy (2013) seeks to improve education for students with vision impairment. In order to do this, it is important to understand how students with visual impairment experience education.…

  10. Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice

    PubMed Central

    Wong, Aimée A.; Brown, Richard E.

    2013-01-01

    The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the “sensory impairment” hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability. PMID:24065919

  11. Vision-model-based impairment metric to evaluate blocking artifacts in digital video

    Microsoft Academic Search

    Zhenghua Yu; Hong Ren Wu; STEFAN WINKLER; Tao Chen

    2002-01-01

    In this paper investigations are conducted to simplify and refine a vision-model-based video quality metric without compromising its prediction accuracy. Unlike other vision-model-based quality metrics, the proposed metric is parameterized using subjective quality assessment data recently provided by the Video Quality Experts Group. The quality metric is able to generate a perceptual distortion map for each and every video frame.

  12. Evaluation of a prototype Minified Augmented-View device for patients with impaired night vision

    Microsoft Academic Search

    Alex R. Bowers; Gang Luo; Noa M. Rensing; Eli Peli

    2004-01-01

    An evaluation was carried out of the first prototype (LV-3) of a new night vision device, which incorporates visual field expansion through minification (Minified Augmented-View), to provide feedback for continuing development. Six subjects with night blindness completed visual function measurements and indoor mobility assessments without a device, with the LV-3 and with a commercially available comparison device (the Multi-Vision) at

  13. Effect of imposed retinal image movements on colour vision at a heterochromatic boundary in a stabilized retinal image.

    PubMed

    Foley-Fisher, J A; Ditchburn, R W

    1986-01-01

    A stabilized image, including a straight-line boundary between two areas of different colour was displayed. Movements normal to itself were imposed on this boundary while other boundaries remained stabilized. Broad band filters giving red, yellow, green and blue were used in various pairs. Step movements, pulse movements and oscillatory movements (including sinusoidal, triangular and square wave forms) were applied in turn. Threshold movements to give perception of hue were measured for steps and pulses and signal/photon-noise ratios were calculated for a red/blue boundary. The ratio was found to be constant at a value of about 20 when the retinal illuminance (ER) varied between 5 td and 60 td. When ER was increased (up to 2000 td) the ratio increased rapidly. None of the colour appearances produced by moving the boundary exactly matched the corresponding appearances in an unstabilized image, though the nearest matches were obtained with oscillatory movements of frequency 2 Hz and displacement greater than 5'. PMID:3627797

  14. Colour constancy in insects.

    PubMed

    Chittka, Lars; Faruq, Samia; Skorupski, Peter; Werner, Annette

    2014-06-01

    Colour constancy is the perceptual phenomenon that the colour of an object appears largely unchanged, even if the spectral composition of the illuminating light changes. Colour constancy has been found in all insect species so far tested. Especially the pollinating insects offer a remarkable opportunity to study the ecological significance of colour constancy since they spend much of their adult lives identifying and choosing between colour targets (flowers) under continuously changing ambient lighting conditions. In bees, whose colour vision is best studied among the insects, the compensation provided by colour constancy is only partial and its efficiency depends on the area of colour space. There is no evidence for complete 'discounting' of the illuminant in bees, and the spectral composition of the light can itself be used as adaptive information. In patchy illumination, bees adjust their spatial foraging to minimise transitions between variously illuminated zones. Modelling allows the quantification of the adaptive benefits of various colour constancy mechanisms in the economy of nature. We also discuss the neural mechanisms and cognitive operations that might underpin colour constancy in insects. PMID:24647930

  15. Changes in Quality of Life in Visually Impaired Patients after Low-Vision Rehabilitation

    ERIC Educational Resources Information Center

    Renieri, Giulia; Pitz, Susanne; Pfeiffer, Norbert; Beutel, Manfred E.; Zwerenz, Rudiger

    2013-01-01

    The objective of the study was to assess the impact of low-vision aids on quality of life. Interviews included a modified version of the National Eye Institute Visual Functioning Questionnaire (Modified German NEI VFQ-25), the Hospital Anxiety and Depression Scale, the Mini-Mental State Examination Blind, and Indicators of the Rehabilitation…

  16. A grayscale pneumatic micro-valve for use in a reconfigurable tactile tablet for vision-impaired individuals

    NASA Astrophysics Data System (ADS)

    Schneider, Joseph Devin; Rebolledo-Mendez, Jovan David; McNamara, Shamus

    2015-01-01

    The design, fabrication, and characterization of a strained bilayer film for use in a micro-valve for a reconfigurable tactile tablet for vision-impaired individuals is presented. The bilayer film consists of a compressive and tensile layer to cause the film to coil and retract from the gas channel when the micro-valve is in the open position. A novel support structure that improves yield and controls the direction of coiling is demonstrated. An array of 225 strained bilayer films was designed and fabricated. Each strained bilayer film was able to be actuated individually with a voltage that ranged between 60 and 70?V. The relationship between the applied voltage and the percentage open of the micro-valve is found to be linear over an extended voltage range, enabling the reconfigurable tactile tablet to produce the equivalent of a grayscale image.

  17. The Psychological Challenge of Late-Life Vision Impairment: Concepts, Findings, and Practical Implications

    PubMed Central

    Wahl, Hans-Werner

    2013-01-01

    The intention is to summarize the body of evidence speaking to the psychological challenges faced by visually impaired older adults, as well as their coping efforts. This evidence is substantiated by a rich set of concepts, theories, and empirical findings that have accumulated under the umbrella of age-related psychoophthalmology (APO). I introduce the field of APO and continue with a discussion of important concepts and theories for a better understanding of adaptational processes in visually impaired older adults. I then summarize the most relevant and most recent data from four areas: (1) everyday competence, (2) cognitive functioning, (3) social functioning, and (4) subjective well-being-related outcomes, depression, and adaptational processes. Thereafter, major insights related to the current state-of-the art psychosocial interventions with visuallyimpaired older adults are reviewed. I close with the need that the public health community should become more aware of and address the psychosocial needs of visually impaired older adults. PMID:23691277

  18. Model Vision Project-Outreach Phase for Severely Handicapped Children and Youth with Visual Impairment. July 1, 1978 to September 30, 1981. Final Report.

    ERIC Educational Resources Information Center

    Harley, Randall K.; And Others

    The document presents the final report of the Model Vision Project (MVP) Outreach Phase, funded to demonstrate appropriate educational, diagnostic, training, and other services to severely multihandicapped, visually impaired children. Roles of various staff are reviewed, and individuals serving as consultants are listed. Summarized are the goals…

  19. revisited: Impaired binocular fusion as a cause of "flat vision" after right parietal brain damage - A case study.

    PubMed

    Schaadt, Anna-Katharina; Brandt, Stephan A; Kraft, Antje; Kerkhoff, Georg

    2015-03-01

    The complete loss of binocular depth perception ("flat vision") was first thoroughly described by Holmes and Horrax (1919), and has been occasionally reported thereafter in patients with bilateral posterior-parietal lesions. Though partial spontaneous recovery occurred in some cases, the precise cause(s) of this condition remained obscure for almost a century. Here, we describe a unique patient (EH) with a large right-sided occipito-parietal hemorrhage showing a complete loss of visual depth perception for several months post-stroke. EH could well simultaneously describe multiple visual objects - hence did not show simultanagnosia - but at the same time was completely unable to estimate their distance from him. In every 3-D visual scene objects appeared equidistant to him, thus experiencing a total loss of depth perception ("flat vision"). Neurovisual assessments revealed normal functions of the eyes. EH showed bilateral lower field loss and a severely impaired binocular convergent fusion, but preserved stereopsis. Perceptual re-training of binocular fusion resulted in a progressive and finally complete recovery of objective binocular fusion values and subjective binocular depth perception in a far-to-near-space, gradient-like manner. In parallel, visual depth estimation of relative distances improved, whereas stereopsis remained unchanged. Our results show that a complete loss of 3-D depth perception can result from an isolated impairment in binocular fusion. On a neuroanatomical level, this connection could be explained by a selective lesion of area V6/V6A in the medial occipito-parietal cortex that has been associated with the integration of visual space coordinates and sustained eye-positions into a cyclopean visual 3-D percept. PMID:25619849

  20. Auditory localization and precedence effect: an exploratory study in infants and toddlers with visual impairment and normal vision.

    PubMed

    Hüg, Mercedes X; Arias, Claudia; Tommasini, Fabián C; Ramos, Oscar A

    2014-09-01

    The precedence effect is a spatial hearing phenomenon implicated in sound localization on reverberant environments. It occurs when a pair of sounds, with a brief delay between them, is presented from different directions; listeners give greater perceptual weight to localization cues coming from the first-arriving sound, called lead, and suppress localization cues from the later-arriving reflection, called lag. Developmental studies with sighted infants show that the first responses to precedence effect stimuli are observed at 4-5 months of life. In this exploratory study, we use the minimum audible angle (MAA) paradigm in conjunction with the observer-based psychophysical procedure to test the ability of infants and toddlers, with visual impairment and normal vision, to discriminate changes in the azimuthal position of sounds configured under precedence effect conditions. The results indicated that similar and, in some conditions, higher performances were obtained by blind toddlers when compared to sighted children of similar age, and revealed that the observer-based psychophysical procedure is a valuable method to measure auditory localization acuity in infants and toddlers with visual impairment. The video records showed auditory orienting behaviors specific of the blind children group. PMID:24864055

  1. Vision Impairs the Abilities of Bats to Avoid Colliding with Stationary Obstacles

    PubMed Central

    Orbach, Dara N.; Fenton, Brock

    2010-01-01

    Background Free-flying insectivorous bats occasionally collide with stationary objects they should easily detect by echolocation and avoid. Collisions often occur with lighted objects, suggesting ambient light may deleteriously affect obstacle avoidance capabilities. We tested the hypothesis that free-flying bats may orient by vision when they collide with some obstacles. We additionally tested whether acoustic distractions, such as “distress calls” of other bats, contributed to probabilities of collision. Methodology/Principal Findings To investigate the role of visual cues in the collisions of free-flying little brown bats (Myotis lucifugus) with stationary objects, we set up obstacles in an area of high bat traffic during swarming. We used combinations of light intensities and visually dissimilar obstacles to verify that bats orient by vision. In early August, bats collided more often in the light than the dark, and probabilities of collision varied with the visibility of obstacles. However, the probabilities of collisions altered in mid to late August, coincident with the start of behavioural, hormonal, and physiological changes occurring during swarming and mating. Distress calls did not distract bats and increase the incidence of collisions. Conclusions/Significance Our findings indicate that visual cues are more important for free-flying bats than previously recognized, suggesting integration of multi-sensory modalities during orientation. Furthermore, our study highlights differences between responses of captive and wild bats, indicating a need for more field experiments. PMID:21085481

  2. Integrated vision-based robotic arm interface for operators with upper limb mobility impairments.

    PubMed

    Jiang, Hairong; Wachs, Juan P; Duerstock, Bradley S

    2013-06-01

    An integrated, computer vision-based system was developed to operate a commercial wheelchair-mounted robotic manipulator (WMRM). In this paper, a gesture recognition interface system developed specifically for individuals with upper-level spinal cord injuries (SCIs) was combined with object tracking and face recognition systems to be an efficient, hands-free WMRM controller. In this test system, two Kinect cameras were used synergistically to perform a variety of simple object retrieval tasks. One camera was used to interpret the hand gestures to send as commands to control the WMRM and locate the operator's face for object positioning. The other sensor was used to automatically recognize different daily living objects for test subjects to select. The gesture recognition interface incorporated hand detection, tracking and recognition algorithms to obtain a high recognition accuracy of 97.5% for an eight-gesture lexicon. An object recognition module employing Speeded Up Robust Features (SURF) algorithm was performed and recognition results were sent as a command for "coarse positioning" of the robotic arm near the selected daily living object. Automatic face detection was also provided as a shortcut for the subjects to position the objects to the face by using a WMRM. Completion time tasks were conducted to compare manual (gestures only) and semi-manual (gestures, automatic face detection and object recognition) WMRM control modes. The use of automatic face and object detection significantly increased the completion times for retrieving a variety of daily living objects. PMID:24187264

  3. Coloured plastinates.

    PubMed

    Steinke, Hanno; Spanel-Borowski, Katharina

    2006-03-01

    To obtain coloured plastinates by colouring anatomical structures in e.g. red, blue and yellow we used different types of chemical reagents. The colours remained stable during dehydration, degreasing and impregnation of specimen with silicone resin. The colours, which penetrated into the specimen, appeared to be included in the plastination process. To prove their stability, the coloured plastinates were exposed to light and heat for more than 5 years. A permanent colouration remained. The coloured plastinates are dry and flexible, odourless and robust. They are instructive and can be used in tutorials, examinations and seminars. PMID:16551016

  4. Adaptive colouration in amphibians.

    PubMed

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians. PMID:23664831

  5. Cav1.4 IT mouse as model for vision impairment in human congenital stationary night blindness type 2

    PubMed Central

    Knoflach, Dagmar; Kerov, Vasily; Sartori, Simone B; Obermair, Gerald J; Schmuckermair, Claudia; Liu, Xiaoni; Sothilingam, Vithiyanjali; Garrido, Marina Garcia; Baker, Sheila A; Glösmann, Martin; Schicker, Klaus; Seeliger, Mathias; Lee, Amy; Koschak, Alexandra

    2013-01-01

    Mutations in the CACNA1F gene encoding the Cav1.4 Ca2+ channel are associated with X-linked congenital stationary night blindness type 2 (CSNB2). Despite the increasing knowledge about the functional behavior of mutated channels in heterologous systems, the pathophysiological mechanisms that result in vision impairment remain to be elucidated. This work provides a thorough functional characterization of the novel IT mouse line that harbors the gain-of-function mutation I745T reported in a New Zealand CSNB2 family.1 Electroretinographic recordings in IT mice permitted a direct comparison with human data. Our data supported the hypothesis that a hyperpolarizing shift in the voltage-dependence of channel activation—as seen in the IT gain-of-function mutant2—may reduce the dynamic range of photoreceptor activity. Morphologically, the retinal outer nuclear layer in adult IT mutants was reduced in size and cone outer segments appeared shorter. The organization of the outer plexiform layer was disrupted, and synaptic structures of photoreceptors had a variable, partly immature, appearance. The associated visual deficiency was substantiated in behavioral paradigms. The IT mouse line serves as a specific model for the functional phenotype of human CSNB2 patients with gain-of-function mutations and may help to further understand the dysfunction in CSNB. PMID:24051672

  6. Vision-related quality of life impairment in an elderly UK population: Associations with age, sex, social class and material deprivation

    Microsoft Academic Search

    Andrew Frost; Jenny Eachus; John Sparrow; Tim J Peters; Cherida Hopper; George Davey-Smith; Stephen Frankel; N A Frost

    2001-01-01

    Purpose To describe the prevalence of vision-related quality of life (VR-QOL) impairment in an elderly UK population sample.Method The survey, using the VCM1 questionnaire, was based on an age- and sex-stratified random population sample of 2783 individuals aged 55 years or over.Results One thousand eight hundred and forty-six (69.7%) of 2647 eligible subjects responded. One thousand six hundred and eighty-three

  7. Low vision due to cerebral visual impairment: differentiating between acquired and genetic causes

    PubMed Central

    2014-01-01

    Background To gain more insight into genetic causes of cerebral visual impairment (CVI) in children and to compare ophthalmological findings between genetic and acquired forms of CVI. Methods The clinical data of 309 individuals (mainly children) with CVI, and a visual acuity ?0.3 were analyzed for etiology and ocular variables. A differentiation was made between acquired and genetic causes. However, in persons with West syndrome or hydrocephalus, it might be impossible to unravel whether CVI is caused by the seizure disorder or increased intracranial pressure or by the underlying disorder (that in itself can be acquired or genetic). In two subgroups, individuals with ‘purely’ acquired CVI and with ‘purely’ genetic CVI, the ocular variables (such as strabismus, pale optic disc and visual field defects) were compared. Results It was possible to identify a putative cause for CVI in 60% (184/309) of the cohort. In the remaining 40% the etiology could not be determined. A ‘purely’ acquired cause was identified in 80 of the patients (26%). West syndrome and/or hydrocephalus was identified in 21 patients (7%), and in 17 patients (6%) both an acquired cause and West and/or hydrocephalus was present. In 66 patients (21%) a genetic diagnosis was obtained, of which 38 (12%) had other possible risk factor (acquired, preterm birth, West syndrome or hydrocephalus), making differentiation between acquired and genetic not possible. In the remaining 28 patients (9%) a ‘purely’ genetic cause was identified. CVI was identified for the first time in several genetic syndromes, such as ATR-X, Mowat-Wilson, and Pitt Hopkins syndrome. In the subgroup with ‘purely’ acquired causes (N?=?80) strabismus (88% versus 64%), pale optic discs (65% versus 27%) and visual field defects (72% versus 30%) could be observed more frequent than in the subgroup with ‘purely’ genetic disorders (N?=?28). Conclusions We conclude that CVI can be part of a genetic syndrome and that abnormal ocular findings are present more frequently in acquired forms of CVI. PMID:24886270

  8. Kids' Quest: Vision Impairment

    MedlinePLUS

    ... HHS), or the U.S. Public Health Service (PHS). Information For... Parents / Educators File Formats Help: How do ... Privacy No FEAR Act Inspector General USA.gov Contact Us National Center on Birth Defects and Developmental ...

  9. Influence of retinopathy on the achromatic and chromatic vision of patients with type 2 diabetes

    PubMed Central

    2014-01-01

    Background Luminance contrast sensitivity and colour vision are considered to have great predictive value in the evaluation of type 2 diabetic retinopathy. However, these two visual characteristics have seldom been investigated in the same group of patients. In the present study we measured contrast sensitivity and colour vision in a group of patients with type 2 diabetes and correlated the results with estimates of common metabolic markers for the disease. A subgroup of the patients had no clinical signs of retinopathy. Methods The vision of 27 patients (n?=?50 eyes) with type 2 diabetes, with retinopathy (n?=?20 eyes), or without retinopathy (n?=?30 eyes) were evaluated using two psychophysical tests, the Farnsworth–Munsell 100 hue test (FM 100), and measurements of the luminance contrast sensitivity at 11 spatial frequencies. The results were compared with measurements obtained from an age-matched control group (n?=?32), and were correlated with the level of glycated haemoglobin, glycaemic level, and time of disease onset. Signs of retinopathy were identified during the ophthalmological examinations. Results Contrast sensitivity and colour vision impairments were present at different levels in diabetes patients. Eyes with retinopathy showed more severe vision loss than eyes without retinopathy. The FM 100 test was more sensitive for separation of patients from controls. Colour vision loss had no colour axes preference. The contrast sensitivity test appeared to have some advantage in differentiating patients with retinopathy from patients without retinopathy. Conclusions Both methods can be useful to follow the visual function of diabetic patients and should be used together to discriminate patients from controls, as well as to identify early signs of retinal damage. PMID:25174264

  10. X-linked cone dystrophy and colour vision deficiency arising from a missense mutation in a hybrid L/M cone opsin gene

    PubMed Central

    McClements, Michelle; Davies, Wayne I L; Michaelides, Michel; Carroll, Joseph; Rha, Jungate; Mollon, John D; Neitz, Maureen; MacLaren, Robert E; Moore, Anthony T; Hunt, David M

    2013-01-01

    In this report, we describe a male subject who presents with a complex phenotype of myopia associated with cone dysfunction and a protan vision deficiency. Retinal imaging demonstrates extensive cone disruption, including the presence of non-waveguiding cones, an overall thinning of the retina, and an irregular mottled appearance of the hyper reflective band associated with the inner segment ellipsoid portion of the photoreceptor. Mutation screening revealed a novel p.Glu41Lys missense mutation in a hybrid L/M opsin gene. Spectral analysis shows that the mutant opsin fails to form a pigment in vitro and fails to be trafficked to the cell membrane in transfected Neuro2a cells. Extensive sequence and quantitative PCR analysis identifies this mutant gene as the only gene present in the affected subject’s L/M opsin gene array, yet the presence of protanopia indicates that the mutant opsin must retain some activity in vivo. To account for this apparent contradiction, we propose that a limited amount of functional pigment is formed within the normal cellular environment of the intact photoreceptor, and that this requires the presence of chaperone proteins that promote stability and normal folding of the mutant protein. PMID:23337435

  11. Cognitive Impairment and Age-Related Vision Disorders: Their Possible Relationship and the Evaluation of the Use of Aspirin and Statins in a 65 Years-and-Over Sardinian Population.

    PubMed

    Mandas, Antonella; Mereu, Rosa Maria; Catte, Olga; Saba, Antonio; Serchisu, Luca; Costaggiu, Diego; Peiretti, Enrico; Caminiti, Giulia; Vinci, Michela; Casu, Maura; Piludu, Stefania; Fossarello, Maurizio; Manconi, Paolo Emilio; Dessí, Sandra

    2014-01-01

    Neurological disorders (Alzheimer's disease, vascular and mixed dementia) and visual loss (cataract, age-related macular degeneration, glaucoma, and diabetic retinopathy) are among the most common conditions that afflict people of at least 65?years of age. An increasing body of evidence is emerging, which demonstrates that memory and vision impairment are closely, significantly, and positively linked and that statins and aspirin may lessen the risk of developing age-related visual and neurological problems. However, clinical studies have produced contradictory results. Thus, the intent of the present study was to reliably establish whether a relationship exist between various types of dementia and age-related vision disorders, and to establish whether statins and aspirin may or may not have beneficial effects on these two types of disorders. We found that participants with dementia and/or vision problems were more likely to be depressed and displayed worse functional ability in basic and instrumental activities of daily living than controls. Mini mental state examination scores were significantly lower in patients with vision disorders compared to subjects without vision disorders. A closer association with macular degeneration was found in subjects with Alzheimer's disease than in subjects without dementia or with vascular dementia, mixed dementia, or other types of age-related vision disorders. When we considered the associations between different types of dementia and vision disorders and the use of statins and aspirin, we found a significant positive association between Alzheimer's disease and statins on their own or in combination with aspirin, indicating that these two drugs do not appear to reduce the risk of Alzheimer's disease or improve its clinical evolution and may, on the contrary, favor its development. No significant association in statin use alone, aspirin use alone, or the combination of these was found in subjects without vision disorders but with dementia, and, similarly, none in subjects with vision disorders but without dementia. Overall, these results confirm the general impression so far; namely, that macular degeneration may contribute to cognitive disorders (Alzheimer's disease in particular). In addition, they also suggest that, while statin and aspirin use may undoubtedly have some protective effects, they do not appear to be magic pills against the development of cognitive impairment or vision disorders in the elderly. PMID:25426067

  12. Cognitive Impairment and Age-Related Vision Disorders: Their Possible Relationship and the Evaluation of the Use of Aspirin and Statins in a 65 Years-and-Over Sardinian Population

    PubMed Central

    Mandas, Antonella; Mereu, Rosa Maria; Catte, Olga; Saba, Antonio; Serchisu, Luca; Costaggiu, Diego; Peiretti, Enrico; Caminiti, Giulia; Vinci, Michela; Casu, Maura; Piludu, Stefania; Fossarello, Maurizio; Manconi, Paolo Emilio; Dessí, Sandra

    2014-01-01

    Neurological disorders (Alzheimer’s disease, vascular and mixed dementia) and visual loss (cataract, age-related macular degeneration, glaucoma, and diabetic retinopathy) are among the most common conditions that afflict people of at least 65?years of age. An increasing body of evidence is emerging, which demonstrates that memory and vision impairment are closely, significantly, and positively linked and that statins and aspirin may lessen the risk of developing age-related visual and neurological problems. However, clinical studies have produced contradictory results. Thus, the intent of the present study was to reliably establish whether a relationship exist between various types of dementia and age-related vision disorders, and to establish whether statins and aspirin may or may not have beneficial effects on these two types of disorders. We found that participants with dementia and/or vision problems were more likely to be depressed and displayed worse functional ability in basic and instrumental activities of daily living than controls. Mini mental state examination scores were significantly lower in patients with vision disorders compared to subjects without vision disorders. A closer association with macular degeneration was found in subjects with Alzheimer’s disease than in subjects without dementia or with vascular dementia, mixed dementia, or other types of age-related vision disorders. When we considered the associations between different types of dementia and vision disorders and the use of statins and aspirin, we found a significant positive association between Alzheimer’s disease and statins on their own or in combination with aspirin, indicating that these two drugs do not appear to reduce the risk of Alzheimer’s disease or improve its clinical evolution and may, on the contrary, favor its development. No significant association in statin use alone, aspirin use alone, or the combination of these was found in subjects without vision disorders but with dementia, and, similarly, none in subjects with vision disorders but without dementia. Overall, these results confirm the general impression so far; namely, that macular degeneration may contribute to cognitive disorders (Alzheimer’s disease in particular). In addition, they also suggest that, while statin and aspirin use may undoubtedly have some protective effects, they do not appear to be magic pills against the development of cognitive impairment or vision disorders in the elderly. PMID:25426067

  13. Sensory impairment in hip-fracture patients 65 years or older and effects of hearing/vision interventions on fall frequency

    PubMed Central

    Grue, Else V; Kirkevold, Marit; Mowinchel, Petter; Ranhoff, Anette H

    2009-01-01

    Aim: Examine the effect of nursing interventions to improve vision and hearing, systematic assessment, and referral to sensory specialists on falling. Methods: Controlled intervention trial targeting hip fracture patients, 65 years and older, living at home and having problems seeing/reading regular print (VI) or hearing normal speech (HI). Intervention group = 200, control group = 131. The InterRAI-AcuteCare (RAI-AC) and the Combined-Serious-Sensory-Impairment interview guide (KAS-Screen) were used. Follow-up telephone calls were done every third month for one year. Results: Mean age was 84.2 years, 79.8% were female, and 76.7% lived alone. HI was detected in 80.7% and VI in 59.8%. Falling was more frequent among the intervention group (P = 0.003) and they also more often moved to a nursing home (P < 0.001) and were dependent walking up stairs (P = 0.003). Conclusions: This study could not document the effect of intervention on falling, possibly because of different base line characteristics (more females, P = 0.018, and more living alone P = 0.011 in the intervention group), differences in nursing care between subjects, and different risk factors. Interventions to improve sensory function remain important in rehabilitation, but have to be studied further. PMID:21197343

  14. Low Vision

    MedlinePLUS Videos and Cool Tools

    ... Symptoms Low Vision Diagnosis and Treatment Low Vision Aids and Low Vision Rehabilitation Low Vision Resources When ... rehabilitation to stay active, including using low vision aids and low vision rehabilitation . If you have low ...

  15. Floral colour diversity in plant communities, bee colour space and a null model

    PubMed Central

    Gumbert, A.; Kunze, J.; Chittka, L.

    1999-01-01

    Evolutionary biologists have long hypothesized that the diversity of flower colours we see is in part a strategy to promote memorization by pollinators, pollinator constancy, and therefore, a directed and efficient pollen transfer between plants. However, this hypothesis has never been tested against a biologically realistic null model, nor were colours assessed in the way pollinators see them. Our intent here is to fill these gaps. Throughout one year, we sampled floral species compositions at five ecologically distinct sites near Berlin, Germany. Bee-subjective colours were quantified for all 168 species. A model of colour vision was used to predict how similar the colours of sympatric and simultaneously blooming flowers were for bees. We then compared flower colour differences in the real habitats with those of random plant communities. We did not find pronounced deviations from chance when we considered common plants. When we examined rare plants, however, we found significant divergence in two of the five plant communities. At one site, similarly coloured species were found to be more frequent than expected, and at the other two locations, flower colours were indistinguishable from a random distribution. These results fit theoretical considerations that rare plants are under stronger selective pressure to secure pollination than common plants. Our study illustrates the power of linking such distinct biological traditions as community ecology and the neuroethology of bee vision.

  16. Topographic Mapping of Residual Vision by Computer

    ERIC Educational Resources Information Center

    MacKeben, Manfred

    2008-01-01

    Many persons with low vision have diseases that damage the retina only in selected areas, which can lead to scotomas (blind spots) in perception. The most frequent of these diseases is age-related macular degeneration (AMD), in which foveal vision is often impaired by a central scotoma that impairs vision of fine detail and causes problems with…

  17. Light Vision Color

    NASA Astrophysics Data System (ADS)

    Valberg, Arne

    2005-04-01

    Light Vision Color takes a well-balanced, interdisciplinary approach to our most important sensory system. The book successfully combines basics in vision sciences with recent developments from different areas such as neuroscience, biophysics, sensory psychology and philosophy. Originally published in 1998 this edition has been extensively revised and updated to include new chapters on clinical problems and eye diseases, low vision rehabilitation and the basic molecular biology and genetics of colour vision. Takes a broad interdisciplinary approach combining basics in vision sciences with the most recent developments in the area Includes an extensive list of technical terms and explanations to encourage student understanding Successfully brings together the most important areas of the subject in to one volume

  18. Prevalence of colour blindness in young Jordanians.

    PubMed

    Al-Aqtum, M T; Al-Qawasmeh, M H

    2001-01-01

    Colour blindness is one of the common genetic disorders observed in all human populations. It is a sex-linked recessive trait. The genes are located on the X chromosome within the Xq28 band. 1,418 university students (1,200 female and 218 male) from Zarka Private University and the Hashemite University were randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates. A total of 23 individuals were found to be colour blind. In females, 4 students (0.33%) were colour blind: 1 of them showed protanomalia, 1 protanopia and 2 deuteranomalia. In males, 19 students (8.72%) were colour blind: 4 showed protanomalia, 3 protanopia, 8 deuteranomalia and 4 deuteranopia. The allelic frequencies of the colour vision gene were found to be 0.087 in males, 0.003 in females and 0.016 in the total population. Studies on colour blindness in Jordan are very few; this population-based investigation is meant to fill a gap in this field. PMID:11125268

  19. Colour Lovers

    NSDL National Science Digital Library

    The endless hues and shades of colors fascinate many persons, including interior-designers, fashionistas, and those who study the workings of the human eye. This particular site is "a place to view, rate and review some lovely colours & palettes." The site contains a number of user forums where people may gather around the electronic glow of the screen to discuss and debate the merits of different colors, along with a place for users to submit their own fanciful and innovative colors. On the right-hand side of the home page, visitors can browse through the top-rated colors, newly added colors, and new palettes. Many of the colors have rather curious names, such as "wegobysundawn" and "victory or ignorance." Of course, there is space provided for visitors to give their own opinions on each color or palette. Overall, a compelling site, and one that will delight those with a penchant for the uses of color.

  20. Spectral sensitivity of a colour changing spider.

    PubMed

    Defrize, Jérémy; Lazzari, Claudio R; Warrant, Eric J; Casas, Jérôme

    2011-04-01

    Vision plays a paramount role in some spider families such as the Salticidae, Lycosidae and Thomisidae, as it is involved in prey hunting, orientation or choice of substrate. In the thomisid Misumena vatia, for which the substrate colour affects the body colour, vision seems to mediate morphological colour changes. However, nothing is known about which component of visual signals from the substrate might be perceived, nor whether M. vatia possesses the physiological basis for colour vision. The aim of this study is thus to investigate the vision of this spider species by measuring the spectral sensitivities of the different pairs of eyes using electrophysiological methods. Extra- and intracellular electrophysiological recordings combined with selective adaptation revealed the presence of two classes of photoreceptor cells, one sensitive in the UV region of the spectrum (around 340 nm) and one sensitive in the green (around 520 nm) regions in the four pairs of eyes. We conclude that M. vatia possesses the physiological potential to perceive both chromatic and achromatic components of the environment. PMID:21300067

  1. Hearing Impairment and Dual Sensory Impairment Are Associated with Increased Mortality in Older Men

    MedlinePLUS

    ... Impairment are Associated with Increased Mortality in Older Men Listen News Brief 09/10/13 Researchers from ... impairment (vision and hearing impairment combined) in older men are associated with increased mortality from cardiovascular disease ( ...

  2. Aging and Vision

    PubMed Central

    Owsley, Cynthia

    2010-01-01

    Given the increasing size of the older adult population in many countries, there is a pressing need to identify the nature of aging-related vision impairments, their underlying mechanisms, and how they impact older adults’ performance of everyday visual tasks. The results of this research can then be used to develop and evaluate interventions to slow or reverse aging-related declines in vision, thereby improving quality of life. Here we summarize salient developments in research on aging and vision over the past 25 years, focusing on spatial contrast sensitivity, vision under low luminance, temporal sensitivity and motion perception, and visual processing speed. PMID:20974168

  3. Why do seals have cones? Behavioural evidence for colour-blindness in harbour seals.

    PubMed

    Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido

    2015-03-01

    All seals and cetaceans have lost at least one of two ancestral cone classes and should therefore be colour-blind. Nevertheless, earlier studies showed that these marine mammals can discriminate colours and a colour vision mechanism has been proposed which contrasts signals from cones and rods. However, these earlier studies underestimated the brightness discrimination abilities of these animals, so that they could have discriminated colours using brightness only. Using a psychophysical discrimination experiment, we showed that a harbour seal can solve a colour discrimination task by means of brightness discrimination alone. Performing a series of experiments in which two harbour seals had to discriminate the brightness of colours, we also found strong evidence for purely scotopic (rod-based) vision at light levels that lead to mesopic (rod-cone-based) vision in other mammals. This finding speaks against rod-cone-based colour vision in harbour seals. To test for colour-blindness, we used a cognitive approach involving a harbour seal trained to use a concept of same and different. We tested this seal with pairs of isoluminant stimuli that were either same or different in colour. If the seal had perceived colour, it would have responded to colour differences between stimuli. However, the seal responded with "same", providing strong evidence for colour-blindness. PMID:25452008

  4. Structural colouration of mammalian skin: convergent evolution of coherently scattering dermal collagen arrays

    E-print Network

    Prum, R. O.; Torres, Rodolfo H.

    2004-05-01

    in mammals In contrast with invertebrates and other vertebrate classes, integumentary structural colouration is rare in mammals (Fox, 1976). In all, violet, blue or green skin is known from only a few genera in the orders of marsupials and primates (Fig.?1... in heterozygous females only (Surridge et al., 2003). The evolution of structurally coloured skin only within mammalian lineages that have advanced, trichromatic colour vision supports the hypothesis that these integumentary colours function in intraspecific...

  5. Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours

    PubMed Central

    Delhey, Kaspar; Burger, Claudia; Fiedler, Wolfgang; Peters, Anne

    2010-01-01

    Background Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed. Methodology/Principal Findings We studied changes in coloration after moult in four passerine birds (robin, Erithacus rubecula; blackbird, Turdus merula; blue tit, Cyanistes caeruleus; and great tit, Parus major) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours. Conclusions/Significance Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling. PMID:20644723

  6. Integrating colour models for more robust feature detection

    NASA Astrophysics Data System (ADS)

    Aldershoff, F.; Gevers, Th.; Stokman, H.

    2006-01-01

    The choice of a colour space is of great importance for many computer vision algorithms (e.g. edge detection and object recognition). It induces the equivalence classes to the actual algorithms. Since there are many colour spaces available, the problem is how to automatically select the weighting to integrate the colour spaces in order to produce the best result for a particular task. In this paper we propose a method to learn these weights, while exploiting the non-perfect correlation between colour spaces of features through the principle of diversification. As a result an optimal trade-off is achieved between repeatability and distinctiveness. The resulting weighting scheme will ensure maximal feature discrimination. The method is experimentally verified for three feature detection tasks: Skin colour detection, edge detection and corner detection. In all three tasks the method achieved an optimal trade-off between (colour) invariance (repeatability) and discriminative power (distinctiveness).

  7. Colour and lighting in hospital design

    NASA Astrophysics Data System (ADS)

    Dalke, Hilary; Little, Jenny; Niemann, Elga; Camgoz, Nilgun; Steadman, Guillaume; Hill, Sarah; Stott, Laura

    2006-06-01

    Little information or guidance has been available to assist the development of a hospital's visual environment. A report on lighting and colour design schemes, accessible to non professionals with responsibility for refurbishment strategies, was required by NHS Estates. Firstly, 20 hospitals were audited to establish a picture of current practice and to identify key issues where colour design could broadly enhance the environment for patients, staff and visitors. Critical areas were outlined in this report, where colour design can be utilised and applied, for the benefit of all users, from ambience to essential legal requirements such as colour contrast for the visually impaired. Provision of staff relaxation rooms that are different in terms of colour and lux levels from immediate work spaces, or thoughtfully designed areas for patients awaiting intensive treatment, have been shown to have some beneficial effects on a sense of well being. Colour and design have not been established as a definite cure for sickness and ill health, but certainly monotony and poor conditions in premises that have not been refurbished with any care, have had a detrimental affect on recovery rates and staff morale. The realisation that a well balanced and attractive environment is of major importance to patients' health is, in no way new; Florence Nightingale observed that 'a variety of form and brilliance of colour in the objects presented to patients are an actual means of recovery'.

  8. Vision and Driving

    PubMed Central

    Owsley, Cynthia; McGwin, Gerald

    2010-01-01

    Driving is the primary means of personal travel in many countries and is relies heavily on vision for its successful execution. Research over the past few decades has addressed the role of vision in driver safety (motor vehicle collision involvement) and in driver performance (both on-road and using interactive simulators in the laboratory). Here we critically review what is currently known about the role of various aspects of visual function in driving. We also discuss translational research issues on vision screening for licensure and re-licensure and rehabilitation of visually impaired persons who want to drive. PMID:20580907

  9. (Computer) Vision without Sight

    PubMed Central

    Manduchi, Roberto; Coughlan, James

    2012-01-01

    Computer vision holds great promise for helping persons with blindness or visual impairments (VI) to interpret and explore the visual world. To this end, it is worthwhile to assess the situation critically by understanding the actual needs of the VI population and which of these needs might be addressed by computer vision. This article reviews the types of assistive technology application areas that have already been developed for VI, and the possible roles that computer vision can play in facilitating these applications. We discuss how appropriate user interfaces are designed to translate the output of computer vision algorithms into information that the user can quickly and safely act upon, and how system-level characteristics affect the overall usability of an assistive technology. Finally, we conclude by highlighting a few novel and intriguing areas of application of computer vision to assistive technology. PMID:22815563

  10. Optimality of the basic colour categories for classification

    PubMed Central

    Griffin, Lewis D

    2005-01-01

    Categorization of colour has been widely studied as a window into human language and cognition, and quite separately has been used pragmatically in image-database retrieval systems. This suggests the hypothesis that the best category system for pragmatic purposes coincides with human categories (i.e. the basic colours). We have tested this hypothesis by assessing the performance of different category systems in a machine-vision task. The task was the identification of the odd-one-out from triples of images obtained using a web-based image-search service. In each triple, two of the images had been retrieved using the same search term, the other a different term. The terms were simple concrete nouns. The results were as follows: (i) the odd-one-out task can be performed better than chance using colour alone; (ii) basic colour categorization performs better than random systems of categories; (iii) a category system that performs better than the basic colours could not be found; and (iv) it is not just the general layout of the basic colours that is important, but also the detail. We conclude that (i) the results support the plausibility of an explanation for the basic colours as a result of a pressure-to-optimality and (ii) the basic colours are good categories for machine vision image-retrieval systems. PMID:16849219

  11. Rockpool Gobies Change Colour for Camouflage

    PubMed Central

    Stevens, Martin; Lown, Alice E.; Denton, Alexander M.

    2014-01-01

    Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

  12. Rockpool gobies change colour for camouflage.

    PubMed

    Stevens, Martin; Lown, Alice E; Denton, Alexander M

    2014-01-01

    Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks) or rapid (seconds and minutes) colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus) for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white), and of different colours (red and blue) and use digital image analysis and modelling of predator (avian) vision to quantify colour and luminance (perceived lightness) changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute), and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation) while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments. PMID:25333382

  13. The Development of Low Vision Therapist Certification.

    ERIC Educational Resources Information Center

    Watson, Gale R.; Quillman, R. Dee; Flax, Marshall; Gerritsen, Bryan

    1999-01-01

    Discusses the development and implementation of the low-vision-therapist certification through the Association for Education and Rehabilitation of the Blind and Visually Impaired. Credentials for professionals in low vision are described, along with required written examination, and the role of the low-vision therapist. (CR)

  14. VISION INSURANCE VISION SERVICE PLAN

    E-print Network

    - 31 - VISION INSURANCE VISION SERVICE PLAN (VSP) Premium Payments Vision coverage is voluntary and premiums are entirely paid by the Employee. To assist in reducing your insurance premium costs, your vision. #12;- 32 - VISION INSURANCE The VSP network provider will contact VSP to verify eligibility and obtain

  15. Colour contribution to children's wayfinding in school environments

    NASA Astrophysics Data System (ADS)

    Helvac?o?lu, Elif; Olguntürk, Nilgün

    2011-03-01

    The purpose of this study was to explore the contribution of colour to children's wayfinding ability in school environments and to examine the differences between colours in terms of their remembrance and usability in route learning process. The experiment was conducted with three different sample groups for each of three experiment sets differentiated by their colour arrangement. The participants totalled 100 primary school children aged seven and eight years old. The study was conducted in four phases. In the first phase, the participants were tested for familiarity with the experiment site and also for colour vision deficiencies by using Ishihara's tests for colour-blindness. In the second phase, they were escorted on the experiment route by the tester one by one, from one starting point to one end point and were asked to lead the tester to the end point by the same route. In the third phase, they were asked to describe verbally the route. In the final phase, they were asked to remember the specific colours at their correct locations. It was found that colour has a significant effect on children's wayfinding performances in school environments. However, there were no differences between different colours in terms of their remembrances in route finding tasks. In addition, the correct identifications of specific colours and landmarks were dependent on their specific locations. Contrary to the literature, gender differences were not found to be significant in the accuracy of route learning performances.

  16. Colour harmony of two colour combinations in clothes matching

    NASA Astrophysics Data System (ADS)

    Wicaksono, Sungging Haryo; Fu, Tzu-Hao; Chen, Liang-Ya; Hou, Chien-Yu; Ou, Li-Chen

    2015-01-01

    There are many definitions and theories about colour harmony. But no consistent rules and definitions can be determined. Some previous researches show that there are many factors that influence the colour harmony. Colour harmony is highly depends on the external factors, including the context of colour besides their colour combinations. In the current research an experiment conducted by observing two colour combinations which applied in shirt and trousers. Twenty observers involved in the experiment, consist of ten male and ten female. Each observer predict colour harmony score in 58 samples of shirt and trouser pairs, the colour combination then applied upside down. Based on the experimental results, male and female group has similar tendency in colour harmony score prediction in the same colour samples (correlation coefficient, r=0.84). Upside down colour combinations will change the impression of observer about colour harmony and yields a different value of colour harmony prediction score which indicated from correlation coefficient results of 0.53.

  17. Can Impaired Vision be Easily, Quickly and Safely Restored toward Health and Maintained Wellness, Using McLeod's Patent Pending Naturoptics Methods?

    NASA Astrophysics Data System (ADS)

    Courtmanche, Amanda; McLeod, Roger; McLeod, David

    2006-10-01

    A healthy eye has its large set of diffraction patterns, generated by the viewed scene, spread across the visible spectrum. Only the two of these simultaneously coincident with foveal cones, and rods, or with extra-foveal cones, are visually useful. This fact and pupil diameter changes with illumination, which cause proportional wavelength changes, drives the healthy visual state. A quasi-monochromatic interval is coincident with foveal cones, and rods. A shorter, partially overlapping interval aligns with extrafoveal cones, with about twenty nanometers separation. Wavelengths follow the Airy disk radius formula. An unhealthy eye is an eyeball deformed by self- induced vision abuse. Incorrect and effectively static stresses in the large external eye muscles displace and distort the patterns. Rebalancing the proper vision and muscle state are safely, quickly and rapidly restored by mimicking natural eye and head movements with naturoptics.

  18. Teaching Visually Impaired Children. Second Edition.

    ERIC Educational Resources Information Center

    Bishop, Virginia E.

    Intended for either the general educator or the specialist, this text offers principles and teaching strategies for teaching students with visual impairments including both blind students and those with low vision. The book is organized into three sections: "Vision,""Learning," and "Testing and Transitions." The four chapters in the "Vision

  19. 21 CFR 886.5910 - Image intensification vision aid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Identification. An image intensification vision aid is a battery-powered device intended for use by a patient who has limited dark adaptation or impaired vision to amplify ambient light. (b) Classification. Class I (general controls). The device...

  20. Reading aids for adults with low vision

    PubMed Central

    Virgili, Gianni; Acosta, Ruthy; Grover, Lori L; Bentley, Sharon A; Giacomelli, Giovanni

    2014-01-01

    Background The purpose of low-vision rehabilitation is to allow people to resume or to continue to perform daily living tasks, with reading being one of the most important. This is achieved by providing appropriate optical devices and special training in the use of residual-vision and low-vision aids, which range from simple optical magnifiers to high-magnification video magnifiers. Objectives To assess the effects of reading aids for adults with low vision. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to January 2013), EMBASE (January 1980 to January 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2013), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister 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 did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 31 January 2013. We searched the reference lists of relevant articles and used the Science Citation Index to find articles that cited the included studies and contacted investigators and manufacturers of low-vision aids. We handsearched the British Journal of Visual Impairment from 1983 to 1999 and the Journal of Visual Impairment and Blindness from 1976 to 1991. Selection criteria This review includes randomised and quasi-randomised trials in which any device or aid used for reading had been compared to another device or aid in people aged 16 or over with low vision as defined by the study investigators. Data collection and analysis At least two authors independently assessed trial quality and extracted data. Main results We included nine small studies with a cross-over-like design (181 people overall) and one study with three parallel arms (243 participants) in the review. All studies reported the primary outcome, results for reading speed. Two studies including 92 participants found moderate- or low-quality evidence suggesting that reading speed is higher with stand-mounted electronic devices or electronic devices with the camera mounted in a ‘mouse’ than with optical magnifiers, which in these trials were generally stand-mounted or, less frequently, hand-held magnifiers or microscopic lenses. In another study of 20 participants there was moderate-quality evidence that optical devices are better than head-mounted electronic devices (four types). There was low-quality evidence from three studies (93 participants) that reading using head-mounted electronic devices is slower than with stand-based electronic devices. The technology of electronic devices may have changed and improved since these studies were conducted. One study suggested no difference between a diffractive spectacle-mounted magnifier and either refractive (15 participants) or aplanatic (15 participants) magnifiers. One study of 10 people suggested that several overlay coloured filters were no better and possibly worse than a clear filter. A parallel-arm study including 243 participants with age-related macular degeneration found that custom or standard prism spectacles were no different from conventional reading spectacles, although the data did not allow precise estimates of performance to be made. Authors' conclusions There is insufficient evidence on the effect of different types of low-vision aids on reading performance. It would be necessary to investigate which patient characteristics predict performance with different devices, including costly electronic devices. Better-quality research should also focus on assessing sustained long-term use of each device. Authors of studies testing several devices on the same person should consider design and

  1. The measurement of vision disability.

    PubMed

    Massof, Robert W

    2002-08-01

    The American Medical Association's (AMA) visual efficiency scale, a vision disability metric based on visual impairment measurements, was adopted in 1925. That scale was based on a 30-year history of theoretical models in vision economics, a misinterpretation of Snellen notation for visual acuity, and an erroneous application of Weber's psychophysical law. The AMA visual efficiency scale survived uncontested for 75 years. In 2001, the AMA adopted a new vision disability scale based on logarithmic transformations of visual acuity and visual field diameter. Like the earlier visual efficiency scale, the new scale is theoretical-it is not supported by any data that speak to the relationship between vision disability and visual impairments. Attempts to measure vision disability date to the early 1980s with the development of self-assessment visual function rating scale questionnaires. Nearly all of the questionnaires developed over the last 20 years use Likert scales, but use them incorrectly. The development of a vision disability metric based on Likert scaling parallels the historical development of other forms of measurement. A tutorial review of psychometrics-classical test theory, item response theory, and Rasch analysis-shows how vision disability measurement scales can be estimated from Likert-type visual function rating scales. We conclude that preliminary data relating measures of vision disability to measures of visual acuity and visual fields support the new AMA vision disability scale. PMID:12199545

  2. Nocturnal hunting of a brightly coloured sit-and-wait predator

    Microsoft Academic Search

    I.-Min Tso; Jen-Pan Huang; Chen-Pan Liao

    2007-01-01

    Many studies have shown that colour signals are important in spidereinsect interactions. The bright body coloration of certain orb-weaving spiders seems to serve as a visual lure to diurnal prey. However, no studies have examined whether this coloration affects spiders' nocturnal hunting. Some nocturnal lepi- dopteran pollinators use colour vision to locate their food resources, so orb-weaving spiders' bright color-

  3. Adaptive coat colour polymorphism in the Kermode bear of coastal British Columbia

    E-print Network

    Reimchen, Thomas E.

    bear (Ursus americanus kermodei Hornaday) occurring on several small islands off the mid vision ­ Ursus americanus kermodei. INTRODUCTION The diversity of general coat colours among terres polymorphisms in a large vertebrate occurs in the coat colour of black bear (Ursus americanus). Throughout most

  4. The Colour of Words.

    ERIC Educational Resources Information Center

    Farrar, Bernice Lever

    Students from the ages of 13 or 14 onward need to know the "colours of words" which can let them live fully in the rainbow of life, thus eliminating student fears associated with written language and of being pawns of those who have the power of words, especially written words. Colour coding the eight basic types of work that words can do in a…

  5. Brand Guidelines Colour version

    E-print Network

    Shoubridge, Eric

    reverse on red Reverse Brand Overview 1.2 The Signature Our signature system is comprised of two elements forbidden. The signature must be inserted into documents from official artwork files only. The full colour, photographic or blended background. This will ensure the wordmark remains legible. Colour reverse on red

  6. A 14-year-old girl who regained normal vision after bilateral visual impairment following hot water injury to the eyes

    Microsoft Academic Search

    Kehinde F. Monsudi; Abdulkabir A. Ayanniyi

    2011-01-01

    A 14-year-old girl presented with bilateral visual impairment following hot water injury to the eyes. The patient was admitted for a week and managed with guttae tropicamide 0.5% 8h, diclofenac sodium 0.1% 4h, and fluoroquinolone 0.3% 6h and ointment chloramphenicol 8h. Also, the patient was managed with capsule doxycycline 100mg 12h for 10days, tablet cataflam 50mg 12h for 7days and

  7. Effects of memory colour on colour constancy for unknown coloured objects

    PubMed Central

    Granzier, Jeroen J M; Gegenfurtner, Karl R

    2012-01-01

    The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects. PMID:23145282

  8. Vision Changes in Space - Duration: 2:20.

    NASA Video Gallery

    This Human Research Program 'Research to Outreach' video featuring NASA Clinical Translational Scientist Jennifer Fogarty explains the risk of vision impairment both during and after spaceflight, i...

  9. Find Services for People Who Are Blind or Visually Impaired

    MedlinePLUS

    ... Programs & Services Technology Evaluation Center on Vision Loss eLearning Center Professional Development Public Policy Center Our Family ... of Visual Impairment & Blindness Center on Vision Loss eLearning Center Contact Us 2 Penn Plaza, Suite 1102 ...

  10. Functional measurements of human ventral occipital cortex: retinotopy and colour.

    PubMed Central

    Wade, Alex R; Brewer, Alyssa A; Rieger, Jochem W; Wandell, Brian A

    2002-01-01

    Human colour vision originates in the cone photoreceptors, whose spatial density peaks in the fovea and declines rapidly into the periphery. For this reason, one expects to find a large representation of the cone-rich fovea in those cortical locations that support colour perception. Human occipital cortex contains several distinct foveal representations including at least two that extend onto the ventral surface: a region thought to be critical for colour vision. To learn more about these ventral signals, we used functional magnetic resonance imaging to identify visual field maps and colour responsivity on the ventral surface. We found a visual map of the complete contralateral hemifield in a 4 cm(2) region adjacent to ventral V3; the foveal representation of this map is confluent with that of areas V1/2/3. Additionally, a distinct foveal representation is present on the ventral surface situated 3-5 cm anterior from the confluent V1/2/3 foveal representations. This organization is not consistent with the definition of area V8, which assumes the presence of a quarter field representation adjacent to V3v. Comparisons of responses to luminance-matched coloured and achromatic patterns show increased activity to the coloured stimuli beginning in area V1 and extending through the new hemifield representation and further anterior in the ventral occipital lobe. PMID:12217168

  11. The Physical Environment and the Visually Impaired.

    ERIC Educational Resources Information Center

    Braf, Per-Gunnar

    Reported are results of a project carried out at the Swedish Institute for the Handicapped to determine needs of the visually impaired in the planning and adaptation of buildings and other forms of physical environment. Chapter 1 considers implications of impaired vision and includes definitions, statistics, and problems of the visually impaired…

  12. Measuring colour rivalry suppression in amblyopia

    PubMed Central

    Hofeldt, T.; Hofeldt, A.

    1999-01-01

    AIMS—To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes.?METHODS—To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed.?RESULTS—In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1.8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (?=1.21, p<0.0001), and negatively related to stereoacuity (?=?0.16, p=0.019). The interocular difference in logMAR acuity was negatively related to stereoacuity (?=?0.13, p=0.009).?CONCLUSIONS—Colour rivalry suppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.?? PMID:10535858

  13. Gene therapy for red-green colour blindness in adult primates

    PubMed Central

    Mancuso, Katherine; Hauswirth, William W.; Li, Qiuhong; Connor, Thomas B.; Kuchenbecker, James A.; Mauck, Matthew C.; Neitz, Jay; Neitz, Maureen

    2009-01-01

    Red-green colour blindness, which results from the absence of either the long- (L) or middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here, the possibility of curing colour blindness using gene therapy was explored in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments1 have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that treatment of congenital vision disorders would be ineffective unless administered to the very young. Here, however, addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders. PMID:19759534

  14. Gene therapy for red-green colour blindness in adult primates.

    PubMed

    Mancuso, Katherine; Hauswirth, William W; Li, Qiuhong; Connor, Thomas B; Kuchenbecker, James A; Mauck, Matthew C; Neitz, Jay; Neitz, Maureen

    2009-10-01

    Red-green colour blindness, which results from the absence of either the long- (L) or the middle- (M) wavelength-sensitive visual photopigments, is the most common single locus genetic disorder. Here we explore the possibility of curing colour blindness using gene therapy in experiments on adult monkeys that had been colour blind since birth. A third type of cone pigment was added to dichromatic retinas, providing the receptoral basis for trichromatic colour vision. This opened a new avenue to explore the requirements for establishing the neural circuits for a new dimension of colour sensation. Classic visual deprivation experiments have led to the expectation that neural connections established during development would not appropriately process an input that was not present from birth. Therefore, it was believed that the treatment of congenital vision disorders would be ineffective unless administered to the very young. However, here we show that the addition of a third opsin in adult red-green colour-deficient primates was sufficient to produce trichromatic colour vision behaviour. Thus, trichromacy can arise from a single addition of a third cone class and it does not require an early developmental process. This provides a positive outlook for the potential of gene therapy to cure adult vision disorders. PMID:19759534

  15. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  16. Illumination Invariant Colour Recognition

    Microsoft Academic Search

    J. Matas; R. Marik; J. Kittler

    1994-01-01

    The article describes a colour based recognition system with three novelfeatures. Firstly, the proposed system can operate in environments wherespectral characteristics of illumination change in both space and time. Secondly,benefits in terms of speed and quality of output are gained by focusingprocessing to areas of salient colour. Finally, an automatic model acquisitionprocedure allows rapid creation of the model database.1 IntroductionIn

  17. Low Vision

    MedlinePLUS

    ... Cases of Low Vision (in thousands) by Age, Gender, and Race/Ethnicity Female/Age White Black Hispanic ... Cases of Low Vision (in thousands) by Age, Gender, and Race/Ethnicity Female/Age White Black Hispanic ...

  18. Early-onset Alzheimers and Cortical Vision Impairment in a Woman With Valosin-containing Protein Disease Associated With 2 APOE [Latin Small Letter Open E]4/APOE [Latin Small Letter Open E]4 Genotype.

    PubMed

    Shamirian, Sharis; Nalbandian, Angèle; Khare, Manaswitha; Castellani, Rudolph; Kim, Ronald; Kimonis, Virginia E

    2015-01-01

    Hereditary inclusion body myopathy is a heterogeneous group of disorders characterized by rimmed vacuoles and by the presence of filamentous cytoplasmic and intranuclear inclusions. Inclusion body myopathy with Paget disease of bone and frontotemporal dementia is a progressive autosomal dominant disorder associated with a mutation in valosin-containing protein (VCP) with typical onset of symptoms in the 30s. APOE [Latin Small Letter Open E]4 is a major risk factor for late-onset Alzheimer disease, a progressive neurodegenerative disorder that affects memory, thinking, behavior, and emotion as a result of the excessive buildup and decreased clearance of ?-amyloid proteins resulting in the appearance of neuritic plaques and neurofibrillary tangles. In conclusion, we report a unique patient with an APOE [Latin Small Letter Open E]4/APOE [Latin Small Letter Open E]4 genotype and atypical VCP disease associated with early Alzheimer disease and severe vision impairment. Future studies will elucidate the interaction of VCP mutations and APOE [Latin Small Letter Open E]4 alleles in understanding common mechanisms in AD and VCP disease. PMID:23715207

  19. Low Vision: Assessment and Training for Mobility.

    ERIC Educational Resources Information Center

    Dodds, Allan G.; Davis, Denis P.

    1987-01-01

    To develop a battery of tasks to predict and improve mobility performance, a series of functional vision tasks (texural shearing, degraded images, embedded figures, and parafoveal attention) were generated by a microcomputer. Sixty visually impaired subjects given either computerized task training or real-life training improved their low vision…

  20. Color Vision Deficits and Literacy Acquisition.

    ERIC Educational Resources Information Center

    Hurley, Sandra Rollins

    1994-01-01

    Shows that color blindness, whether partial or total, inhibits literacy acquisition. Offers a case study of a third grader with impaired color vision. Presents a review of literature on the topic. Notes that people with color vision deficits are often unaware of the handicap. (RS)

  1. Neurological Vision Rehabilitation: Description and Case Study

    ERIC Educational Resources Information Center

    Kingston, John; Katsaros, Jennifer; Vu, Yurika; Goodrich, Gregory L.

    2010-01-01

    The wars in Afghanistan and Iraq have been notable for the high rates of traumatic brain injury (TBI) that have been incurred by the troops. Visual impairments often occur following TBI and present new challenges for rehabilitation. We describe a neurological vision rehabilitation therapy that addresses the unique needs of patients with vision…

  2. Colour in flux: describing and printing colour in art

    NASA Astrophysics Data System (ADS)

    Parraman, Carinna

    2008-01-01

    This presentation will describe artists, practitioners and scientists, who were interested in developing a deeper psychological, emotional and practical understanding of the human visual system who were working with wavelength, paint and other materials. From a selection of prints at The Prints and Drawings Department at Tate London, the presentation will refer to artists who were motivated by issues relating to how colour pigment was mixed and printed, to interrogate and explain colour perception and colour science, and in art, how artists have used colour to challenge the viewer and how a viewer might describe their experience of colour. The title Colour in Flux refers, not only to the perceptual effect of the juxtaposition of one colour pigment with another, but also to the changes and challenges for the print industry. In the light of screenprinted examples from the 60s and 70s, the presentation will discuss 21 st century ideas on colour and how these notions have informed the Centre for Fine Print Research's (CFPR) practical research in colour printing. The latter part of this presentation will discuss the implications for the need to change methods in mixing inks that moves away from existing colour spaces, from non intuitive colour mixing to bespoke ink sets, colour mixing approaches and colour mixing methods that are not reliant on RGB or CMYK.

  3. Age-Related Psychophysical Changes and Low Vision

    PubMed Central

    Dagnelie, Gislin

    2013-01-01

    When considering the burden of visual impairment on aging individuals and society at large, it is important to bear in mind that vision changes are a natural aspect of aging. In this article, we consider vision changes that are part of normal aging, the prevalence of abnormal vision changes caused by disorders of the visual system, and the anticipated incidence and impact of visual impairment as the US population ages. We then discuss the services available to reduce the impact of vision loss, and the extent to which those services can and should be improved, not only to be better prepared for the anticipated increase in low vision over the coming decades, but also to increase the awareness of interactions between visual impairment and comorbidities that are common among the elderly. Finally, we consider how to promote improved quality, availability, and acceptance of low vision care to lessen the impact of visual impairment on individuals, and its burden on society. PMID:24335074

  4. What You Need to Know about Low Vision

    MedlinePLUS

    ... Students with Low Vision Back to : Low Vision Directory of Services Find Local Services: Browse Services Featured ... Family of Sites FamilyConnect ® CareerConnect ® VisionAware ™ Braille Bug ® Directory Center AccessWorld ® Journal of Visual Impairment & Blindness Center ...

  5. The Need for a Uniform Method of Recording and Reporting Functional Vision Assessments

    ERIC Educational Resources Information Center

    Shaw, Rona; Russotti, Joanne; Strauss-Schwartz, Judy; Vail, Helen; Kahn, Ronda

    2009-01-01

    The use of functional vision by school-age students who have visual impairments, including those with additional disabilities, is typically reported by teachers of students with visual impairments. Functional vision assessments determine how well a student uses his or her vision to perform tasks throughout the school day. The information that is…

  6. Mimicry, colour forms and spectral sensitivity of the bluestriped fangblenny, Plagiotremus rhinorhynchos

    PubMed Central

    Cheney, Karen L.; Skogh, Charlotta; Hart, Nathan S.; Marshall, N. Justin

    2009-01-01

    Animals change their body coloration for a variety of purposes including communication, thermoregulation and crypsis. The cues that trigger adaptive colour change are often unclear, and the role of colour vision remains largely untested. Here, we investigated the bluestriped fangblenny (Plagiotremus rhinorhynchos), an aggressive mimic that changes its body coloration to impersonate a variety of coral reef fishes. In this field, we determined the fish species that the fangblenny associated with and measured the spectral reflectance of mimics and their models. We measured the spectral absorbance characteristics of the retinal photoreceptor visual pigments in the bluestriped fangblenny using microspectrophotometry and found it to have rod photoreceptors (?max 498?nm), single cones (449?nm) and double cones (561?nm principal member; 520?nm accessory member). Using theoretical vision models, fangblennies could discriminate between the colours they adopted and the colours of the fish they associated with. Potential signal receivers (Abudefduf abdominalis and Ctenochaetus strigosus) perceived colours of most mimics to closely resemble fishes they associated with. However, fishes with ultraviolet-sensitive visual pigments were better at discriminating between mimics and models. Therefore, colour vision could be used by fangblennies when initiating colour change enabling them to accurately resemble fishes they associate with and to avoid detection by signal receivers. PMID:19324827

  7. Mimicry, colour forms and spectral sensitivity of the bluestriped fangblenny, Plagiotremus rhinorhynchos.

    PubMed

    Cheney, Karen L; Skogh, Charlotta; Hart, Nathan S; Marshall, N Justin

    2009-05-01

    Animals change their body coloration for a variety of purposes including communication, thermoregulation and crypsis. The cues that trigger adaptive colour change are often unclear, and the role of colour vision remains largely untested. Here, we investigated the bluestriped fangblenny (Plagiotremus rhinorhynchos), an aggressive mimic that changes its body coloration to impersonate a variety of coral reef fishes. In this field, we determined the fish species that the fangblenny associated with and measured the spectral reflectance of mimics and their models. We measured the spectral absorbance characteristics of the retinal photoreceptor visual pigments in the bluestriped fangblenny using microspectrophotometry and found it to have rod photoreceptors (lambda(max) 498 nm), single cones (449 nm) and double cones (561 nm principal member; 520 nm accessory member). Using theoretical vision models, fangblennies could discriminate between the colours they adopted and the colours of the fish they associated with. Potential signal receivers (Abudefduf abdominalis and Ctenochaetus strigosus) perceived colours of most mimics to closely resemble fishes they associated with. However, fishes with ultraviolet-sensitive visual pigments were better at discriminating between mimics and models. Therefore, colour vision could be used by fangblennies when initiating colour change enabling them to accurately resemble fishes they associate with and to avoid detection by signal receivers. PMID:19324827

  8. Transmission of colour and acuity signals by parvocellular cells in marmoset monkeys

    PubMed Central

    Martin, Paul R; Blessing, Esther M; Buzás, Péter; Szmajda, Brett A; Forte, Jason D

    2011-01-01

    Abstract The red–green axis of colour vision evolved recently in primate evolutionary history. Signals serving red–green colour vision travel together with signals serving spatial vision, in the parvocellular (PC) division of the subcortical visual pathway. However, the question of whether receptive fields of PC pathway cells are specialized to transmit red–green colour signals remains unresolved. We addressed this question in single-cell recordings from the lateral geniculate nucleus of anaesthetized marmosets. Marmosets show a high proportion of dichromatic (red–green colour-blind) individuals, allowing spatial and colour tuning properties of PC cells to be directly compared in dichromatic and trichromatic visual systems. We measured spatial frequency tuning for sine gratings that provided selective stimulation of individual photoreceptor types. We found that in trichromatic marmosets, the foveal visual field representation is dominated by red–green colour-selective PC cells. Colour selectivity of PC cells is reduced at greater eccentricities, but cone inputs to centre and surround are biased to create more selectivity than predicted by a purely ‘random wiring’ model. Thus, one-to-one connections in the fovea are sufficient, but not necessary, to create colour-selective responses. The distribution of spatial tuning properties for achromatic stimuli shows almost complete overlap between PC cells recorded in dichromatic and trichromatic marmosets. These data indicate that transmission of red–green colour signals has been enabled by centre–surround receptive fields of PC cells, and has not altered the capacity of PC cells to serve high-acuity vision at high stimulus contrast. PMID:21486786

  9. Colour: A Computer Program for QCD Colour Factor Calculations

    E-print Network

    Jari Hakkinen; Hamid Kharraziha

    1996-03-04

    A computer program for evaluating colour factors of QCD Feynman diagrams is presented, and illustrative examples on how to use the program to calculate non trivial colour factors are given. The program and the discussion in this paper is based on a diagrammatic approach to colour factors.

  10. Colouration in crab spiders: substrate choice and prey attraction.

    PubMed

    Heiling, Astrid M; Chittka, Lars; Cheng, Ken; Herberstein, Marie E

    2005-05-01

    Australian crab spiders Thomisus spectabilis ambush pollinating insects, such as honeybees (Apis mellifera) on flowers, and can change their body colour between yellow and white. It is traditionally assumed that the spiders change their colour to match the flower colour, thus rendering them cryptic to insect prey. Here, we test this assumption combining state-of-the-art knowledge of bee vision and behavioural experiments. In the field, yellow spiders are only found on yellow daisies (Chrysanthemum frutescens), whereas white spiders are found on yellow and white daisies. These field patterns were confirmed in the laboratory. When given the choice between white and yellow daisies, yellow spiders preferred yellow daisies, whereas white spiders showed only a slight but non-significant preference for white flowers. Thus, T. spectabilis select background colours according to their own body colour. When viewed from a distance, bees use an achromatic signal produced by their green receptors for target detection. Through this visual channel, white spiders on white flowers, and yellow spiders on yellow flowers are virtually undetectable. From a closer distance of a few centimetres, when bees evaluate colour contrast, the combination of spider colour against different flower backgrounds affected the response of honeybees, but not in ways predicted by a classical crypsis/conspicuousness interpretation. Yellow spiders on yellow flowers are not perfectly matched when interpreted through the colour vision of a honeybee. Nevertheless, honeybees showed indifference to the presence of a spider, equally landing on vacant or spider-occupied flowers. Likewise, white spiders are poorly hidden on white flowers, as white spiders reflect ultraviolet light strongly, while white flowers do not. Surprisingly, bees are attracted to this contrast, and significantly more honeybees preferred white flowers occupied by white spiders. White spiders on yellow flowers produce the highest colour contrast and bees again preferred spider-occupied flowers. Yellow spiders on white flowers were the only pairing where bees rejected spider-occupied flowers, especially in cases where the contrast between the two was relatively strong. Thus, T. spectabilis select flower colours adaptively in a way that deceives honeybees, or at least does not deter them. PMID:15879060

  11. Bullying in German Adolescents: Attending Special School for Students with Visual Impairment

    ERIC Educational Resources Information Center

    Pinquart, Martin; Pfeiffer, Jens P.

    2011-01-01

    The present study analysed bullying in German adolescents with and without visual impairment. Ninety-eight adolescents with vision loss from schools for students with visual impairment, of whom 31 were blind and 67 had low vision, were compared with 98 sighted peers using a matched-pair design. Students with low vision reported higher levels of…

  12. VISION INSURANCE VISION SERVICE PLAN (VSP)

    E-print Network

    - 38 - VISION INSURANCE VISION SERVICE PLAN (VSP) Premium Payments Vision coverage is voluntary and premiums are entirely paid by the Employee. To assist in reducing your insurance premium costs, your vision

  13. Colour cues proved to be more informative for dogs than brightness

    PubMed Central

    Kasparson, Anna A.; Badridze, Jason; Maximov, Vadim V.

    2013-01-01

    The results of early studies on colour vision in dogs led to the conclusion that chromatic cues are unimportant for dogs during their normal activities. Nevertheless, the canine retina possesses two cone types which provide at least the potential for colour vision. Recently, experiments controlling for the brightness information in visual stimuli demonstrated that dogs have the ability to perform chromatic discrimination. Here, we show that for eight previously untrained dogs colour proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity. Although brightness could have been used by the dogs in our experiments (unlike previous studies), it was not. Our results demonstrate that under natural photopic lighting conditions colour information may be predominant even for animals that possess only two spectral types of cone photoreceptors. PMID:23864600

  14. The Role of Organizations in Reaching Older Adults about Vision Loss

    ERIC Educational Resources Information Center

    Sussman-Skalka, Carol J.; Cimarolli, Verena R.; Stuen, Cynthia

    2006-01-01

    Vision impairment affects approximately 17% of Americans age 45 and older. Yet, 94% of adults with self-reported vision loss did not receive any type of vision rehabilitation services to help them retain independence. These findings underscore the need for promoting awareness about what can be done when vision fails. A national dissemination…

  15. Blobs versus bars: Psychophysical evidence supports two types of orientation response in human color vision

    E-print Network

    Mullen, Kathy T.

    color vision Mina Gheiratmand $ McGill Vision Research, Department of Ophthalmology, McGill University, UK Kathy T. Mullen # $ McGill Vision Research, Department of Ophthalmology, McGill University of psychophysical studies has demonstrated that color vision has orientation-tuned responses and little impairment

  16. Colour based fire detection method with temporal intensity variation filtration

    NASA Astrophysics Data System (ADS)

    Trambitckii, K.; Anding, K.; Musalimov, V.; Linß, G.

    2015-02-01

    Development of video, computing technologies and computer vision gives a possibility of automatic fire detection on video information. Under that project different algorithms was implemented to find more efficient way of fire detection. In that article colour based fire detection algorithm is described. But it is not enough to use only colour information to detect fire properly. The main reason of this is that in the shooting conditions may be a lot of things having colour similar to fire. A temporary intensity variation of pixels is used to separate them from the fire. These variations are averaged over the series of several frames. This algorithm shows robust work and was realised as a computer program by using of the OpenCV library.

  17. Hyperbolic geometry for colour metrics.

    PubMed

    Farup, Ivar

    2014-05-19

    It is well established from both colour difference and colour order perpectives that the colour space cannot be Euclidean. In spite of this, most colour spaces still in use today are Euclidean, and the best Euclidean colour metrics are performing comparably to state-of-the-art non-Euclidean metrics. In this paper, it is shown that a transformation from Euclidean to hyperbolic geometry (i.e., constant negative curvature) for the chromatic plane can significantly improve the performance of Euclidean colour metrics to the point where they are statistically significantly better than state-of-the-art non-Euclidean metrics on standard data sets. The resulting hyperbolic geometry nicely models both qualitatively and quantitatively the hue super-importance phenomenon observed in colour order systems. PMID:24921355

  18. Machine Vision

    NSDL National Science Digital Library

    Leske, Cavin.

    An overview of a generic image-based machine vision system is provided on this Web site (1). The tutorial describes the main components of such a system, how its accuracy is measured, and what scientific and industrial applications benefit from machine vision. A more technical perspective of machine vision technology is given in an online publication of the Automated Imaging Association (2). Monthly feature articles discuss breaking issues related to machine vision, and several technical papers can be downloaded, which are sorted into categories such as three dimensional imaging and nanotechnology. Researchers from the MIT's Artificial Intelligence Laboratory (3) are investigating how to enable a computer to interpret visual and audio signals from its human user. By using machine perception systems to track the user's gaze, for example, the computer could ascertain the focus of the user's attention, thereby facilitating interaction between the human and the computer. The project's homepage includes numerous research papers, as well as video demonstrations of some of its systems. Machine vision is also finding its way into vehicles. A March 2003 news article (4) highlights a field test in Michigan of a collision avoidance system that uses, among other things, machine vision to warn drivers that they are approaching a slower or stopped object too quickly. The 3D Computer Vision Group at Carnegie Mellon University (5) is involved in several projects, including three dimensional object recognition and humanoid robot vision. Many of the group's recent publications are available for download. NASA's Mars Exploration Rovers, the second of which was launched in July 2003, have vision systems that will let them safely navigate rough terrain. These systems are described in this conference paper (6), including specifics of the stereo vision algorithm and insights into future missions. A new implementation of machine vision comes from a former researcher from Cambridge University. His shape recognition system, which is detailed in this news article (7), is reportedly much more related to human visual processes than existing techniques. For additional developments related to this evolving technology, Machine Vision News (8) has information about worldwide research and new applications of machine vision systems.

  19. Distinctive convergence in Australian floral colours seen through the eyes of Australian birds

    PubMed Central

    Burd, Martin; Stayton, C. Tristan; Shrestha, Mani; Dyer, Adrian G.

    2014-01-01

    We used a colour-space model of avian vision to assess whether a distinctive bird pollination syndrome exists for floral colour among Australian angiosperms. We also used a novel phylogenetically based method to assess whether such a syndrome represents a significant degree of convergent evolution. About half of the 80 species in our sample that attract nectarivorous birds had floral colours in a small, isolated region of colour space characterized by an emphasis on long-wavelength reflection. The distinctiveness of this ‘red arm’ region was much greater when colours were modelled for violet-sensitive (VS) avian vision than for the ultraviolet-sensitive visual system. Honeyeaters (Meliphagidae) are the dominant avian nectarivores in Australia and have VS vision. Ancestral state reconstructions suggest that 31 lineages evolved into the red arm region, whereas simulations indicate that an average of five or six lineages and a maximum of 22 are likely to have entered in the absence of selection. Thus, significant evolutionary convergence on a distinctive floral colour syndrome for bird pollination has occurred in Australia, although only a subset of bird-pollinated taxa belongs to this syndrome. The visual system of honeyeaters has been the apparent driver of this convergence. PMID:24573847

  20. Computer vision

    NASA Technical Reports Server (NTRS)

    Gennery, D.; Cunningham, R.; Saund, E.; High, J.; Ruoff, C.

    1981-01-01

    The field of computer vision is surveyed and assessed, key research issues are identified, and possibilities for a future vision system are discussed. The problems of descriptions of two and three dimensional worlds are discussed. The representation of such features as texture, edges, curves, and corners are detailed. Recognition methods are described in which cross correlation coefficients are maximized or numerical values for a set of features are measured. Object tracking is discussed in terms of the robust matching algorithms that must be devised. Stereo vision, camera control and calibration, and the hardware and systems architecture are discussed.

  1. Computational vision

    NASA Technical Reports Server (NTRS)

    Barrow, H. G.; Tenenbaum, J. M.

    1981-01-01

    The range of fundamental computational principles underlying human vision that equally apply to artificial and natural systems is surveyed. There emerges from research a view of the structuring of vision systems as a sequence of levels of representation, with the initial levels being primarily iconic (edges, regions, gradients) and the highest symbolic (surfaces, objects, scenes). Intermediate levels are constrained by information made available by preceding levels and information required by subsequent levels. In particular, it appears that physical and three-dimensional surface characteristics provide a critical transition from iconic to symbolic representations. A plausible vision system design incorporating these principles is outlined, and its key computational processes are elaborated.

  2. Specifying colour and maintaining colour accuracy for 3D printing

    Microsoft Academic Search

    Carinna Parraman; Peter Walters; Brendan Reid; David Huson

    2008-01-01

    Advances in rapid prototyping technologies have led to the emergence of three-dimensional printers which can fabricate physical artefacts, including the application of surface colours. In light of these developments, this paper asserts that the need to print colour accurately is just as important for designers using three-dimensional colour printing as it is for two-dimensional inkjet printing. Parallels can be made

  3. Vision Memo

    E-print Network

    Minsky, Marvin

    1967-02-01

    This Memo proposes a set of systems programs for vision work. Please comment immediately as we should start on it at once. Values stored outside an array range should have no effect, but set an overflow flag: values read ...

  4. Improving Vision

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Many people are familiar with the popular science fiction series Star Trek: The Next Generation, a show featuring a blind character named Geordi La Forge, whose visor-like glasses enable him to see. What many people do not know is that a product very similar to Geordi's glasses is available to assist people with vision conditions, and a NASA engineer's expertise contributed to its development. The JORDY(trademark) (Joint Optical Reflective Display) device, designed and manufactured by a privately-held medical device company known as Enhanced Vision, enables people with low vision to read, write, and watch television. Low vision, which includes macular degeneration, diabetic retinopathy, and glaucoma, describes eyesight that is 20/70 or worse, and cannot be fully corrected with conventional glasses.

  5. Vision problems

    MedlinePLUS

    ... sugar under control if you have diabetes. Eat foods rich in antioxidants, like green leafy vegetables. ... Tomsak RL. Vision loss. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in ...

  6. Grey leaves in an alpine plant: a cryptic colouration to avoid attack?

    PubMed

    Niu, Yang; Chen, Gao; Peng, De-Li; Song, Bo; Yang, Yang; Li, Zhi-Min; Sun, Hang

    2014-08-01

    Cryptic colouration is a common predation-avoidance strategy in animals that is postulated to occur in plants, but few experimental studies have rigorously tested this hypothesis. We investigated the colouration of Corydalis benecincta, an alpine plant with remarkably dimorphic leaf colours (grey and green), based on a cost-benefit analysis. First we tested the premise that herbivores (Parnassius butterflies) cannot distinguish grey leaves from a scree background by spectrographic measurements and by estimating discriminability between leaves and scree using a butterfly colour vision model. Then we estimated the potential costs of inconspicuousness by comparing the photosynthetic performance and visual attractiveness to flower visitors of the two colour morphs. Finally, we examined the potential benefits of inconspicuousness by comparing damage, survivorship and female reproductive success. It is difficult for herbivores to distinguish grey-coloured morphs against the background. This grey colour originates in a combination of anthocyanins and chlorophylls. The two colour morphs had similar photosynthetic performance, visual attractiveness and female reproductive success. However, grey morphs had significantly lower herbivore damage and higher survivorship. Grey leaves benefit C. benecincta by reducing herbivory with low investment in anthocyanin synthesis, and little cost on photosynthesis and mating opportunity. This cryptic colouration may have evolved through selection pressure imposed by visually foraging herbivores. PMID:24800901

  7. Class separation improvements in pixel classification using colour injection.

    PubMed

    Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

    2010-01-01

    This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC(1)C(2)) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required. PMID:22163628

  8. Texture Variations Suppress Suprathreshold Brightness and Colour Variations

    PubMed Central

    Schofield, Andrew J.; Kingdom, Frederick A. A.

    2014-01-01

    Discriminating material changes from illumination changes is a key function of early vision. Luminance cues are ambiguous in this regard, but can be disambiguated by co-incident changes in colour and texture. Thus, colour and texture are likely to be given greater prominence than luminance for object segmentation, and better segmentation should in turn produce stronger grouping. We sought to measure the relative strengths of combined luminance, colour and texture contrast using a suprathreshhold, psychophysical grouping task. Stimuli comprised diagonal grids of circular patches bordered by a thin black line and contained combinations of luminance decrements with either violet, red, or texture increments. There were two tasks. In the Separate task the different cues were presented separately in a two-interval design, and participants indicated which interval contained the stronger orientation structure. In the Combined task the cues were combined to produce competing orientation structure in a single image. Participants had to indicate which orientation, and therefore which cue was dominant. Thus we established the relative grouping strength of each cue pair presented separately, and compared this to their relative grouping strength when combined. In this way we observed suprathreshold interactions between cues and were able to assess cue dominance at ecologically relevant signal levels. Participants required significantly more luminance and colour compared to texture contrast in the Combined compared to Separate conditions (contrast ratios differed by about 0.1 log units), showing that suprathreshold texture dominates colour and luminance when the different cues are presented in combination. PMID:25502555

  9. The colours of the Sun

    E-print Network

    Johan Holmberg; Chris Flynn; Laura Portinari

    2005-11-06

    We compile a sample of Sun-like stars with accurate effective temperatures, metallicities and colours (from the UV to the near-IR). A crucial improvement is that the effective temperature scale of the stars has recently been established as both accurate and precise through direct measurement of angular diameters obtained with stellar interferometers. We fit the colours as a function of effective temperature and metallicity, and derive colour estimates for the Sun in the Johnson/Cousins, Tycho, Stromgren, 2MASS and SDSS photometric systems. For (B-V)_Sun, we favour the ``red'' colour 0.64 versus the ``blue'' colour 0.62 of other recent papers, but both values are consistent within the errors; we ascribe the difference to the selection of Sun-like stars versus interpolation of wider colour-Teff-metallicity relations.

  10. The effect of an on-site vision examination on adherence to vision screening recommendations.

    PubMed

    Chu, Raymond; Huang, Kristine; Barnhardt, Carmen; Chen, Angela

    2015-04-01

    Vision screenings are intended to efficiently identify students with possible visual impairment and initiate a referral for diagnosis and treatment. In many cases, at-risk students do not access the recommended care or experience delays in receiving care. The purpose of this article is to report the effect on adherence to vision screening recommendations by providing the eye examination at the students' school and at no cost. Of the 1,306 students screened, 382 (29.2%) were identified with possible visual impairment. Parental consent for examination was obtained for 198 (51.8%) students. Our vision screening and examination program yielded similar adherence to follow-up as stand-alone vision screening programs. Future program considerations should address perceptual barriers that may be contributing to parental nonadherence to vision screening recommendations. PMID:24574183

  11. Digital colour management system for colour parameters reconstruction

    NASA Astrophysics Data System (ADS)

    Grudzinski, Karol; Lasmanowicz, Piotr; Assis, Lucas M. N.; Pawlicka, Agnieszka; Januszko, Adam

    2013-10-01

    Digital Colour Management System (DCMS) and its application to new adaptive camouflage system are presented in this paper. The DCMS is a digital colour rendering method which would allow for transformation of a real image into a set of colour pixels displayed on a computer monitor. Consequently, it can analyse pixels' colour which comprise images of the environment such as desert, semi-desert, jungle, farmland or rocky mountain in order to prepare an adaptive camouflage pattern most suited for the terrain. This system is described in present work as well as the use the subtractive colours mixing method to construct the real time colour changing electrochromic window/pixel (ECD) for camouflage purpose. The ECD with glass/ITO/Prussian Blue(PB)/electrolyte/CeO2-TiO2/ITO/glass configuration was assembled and characterized. The ECD switched between green and yellow after +/-1.5 V application and the colours have been controlled by Digital Colour Management System and described by CIE LAB parameters.

  12. Disruptive Colouration and Perceptual Grouping

    PubMed Central

    Espinosa, Irene; Cuthill, Innes C.

    2014-01-01

    Camouflage is the primary defence of many animals and includes multiple strategies that interfere with figure-ground segmentation and object recognition. While matching background colours and textures is widespread and conceptually straightforward, less well explored are the optical ‘tricks’, collectively called disruptive colouration, that exploit perceptual grouping mechanisms. Adjacent high contrast colours create false edges, but this is not sufficient for an object’s shape to be broken up; some colours must blend with the background. We test the novel hypothesis that this will be particularly effective when the colour patches on the animal appear to belong to, not merely different background colours, but different background objects. We used computer-based experiments where human participants had to find cryptic targets on artificial backgrounds. Creating what appeared to be bi-coloured foreground objects on bi-coloured backgrounds, we generated colour boundaries that had identical local contrast but either lay within or between (illusory) objects. As predicted, error rates for targets matching what appeared to be different background objects were higher than for targets which had otherwise identical local contrast to the background but appeared to belong to single background objects. This provides evidence for disruptive colouration interfering with higher-level feature integration in addition to previously demonstrated low-level effects involving contour detection. In addition, detection was impeded in treatments where targets were on or in close proximity to multiple background colour or tone boundaries. This is consistent with other studies which show a deleterious influence of visual ‘clutter’ or background complexity on search. PMID:24466337

  13. Pediatric Low Vision

    MedlinePLUS

    ... Eye Drops Lazy eye (defined) Pink eye (defined) Retinopathy of Prematurity Strabismus Stye (defined) Vision Screening Vision Screening Recommendations ... Eye Drops Lazy eye (defined) Pink eye (defined) Retinopathy of Prematurity Strabismus Stye (defined) Vision Screening Vision Screening Recommendations ...

  14. Computer vision

    SciTech Connect

    Rosenfeld, A.

    1982-04-01

    Over the past 25 years, much of the work on applications of pattern recognition, and a significant fraction of the work in artificial intelligence, has dealt with the analysis and in artificial intelligence, has dealt with the analysis and interpretation of images. This subject has been variously known as pictorial pattern recognition, image analysis, scene analysis, image understanding, and computer vision. Its applications include document processing (character recognition, etc.), microscopy, radiology, industrial automation (inspection, robot vision), remote sensing, navigation, and reconaissance, to name only the major areas. Many ad hoc techniques for analyzing images have been developed, so that a large assortment of tools is now available for solving practical problems in this field. Most important, during the past few years the field has begun to develop a scientific basis. This paper outlines the major steps in the computer vision process, and summarizes the state of the art with respect to each of these steps.

  15. Colour map design through optimization

    NASA Astrophysics Data System (ADS)

    Nolle, Lars; Schaefer, Gerald

    2007-04-01

    Often in engineering systems, full-colour images have to be displayed on limited hardware, for example on mobile devices or embedded systems that can only handle a limited number of colours. Therefore an image is converted into an indexed map from where the indices point to specific colours in a fixed-size colour map generated for that image. The choice of an optimal colour map, or palette, is therefore crucial as it directly determines the quality of the resulting image. Typically, standard quantization algorithms are used to create colour maps. Whereas these algorithms employ domain specific knowledge, in this work a variant of simulated annealing (SA) was employed as a standard black-box optimization algorithm for colour map generation. The main advantage of black-box optimization algorithms is that they do not require any domain specific knowledge yet are able to provide a near optimal solution. The effectiveness of the approach is evaluated by comparing its performance with several specialized colour quantization algorithms. The results obtained show that even without any domain specific knowledge the SA based algorithm is able to outperform standard quantization algorithms. To further improve the performance of the algorithm the SA technique was combined with a standard k-means clustering technique. This hybrid quantization algorithm is shown to outperform all other algorithms and hence to provide images with superior image quality.

  16. Reversible colour change in Arthropoda.

    PubMed

    Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

    2014-11-01

    The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry. PMID:24495279

  17. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...criteria: Visual impairment including blindness. 1308.13 Section 1308.13 Public...criteria: Visual impairment including blindness. (a) A child is classified as...vision loss meets the definition of legal blindness in the State of residence; or...

  18. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...criteria: Visual impairment including blindness. 1308.13 Section 1308.13 Public...criteria: Visual impairment including blindness. (a) A child is classified as...vision loss meets the definition of legal blindness in the State of residence; or...

  19. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...criteria: Visual impairment including blindness. 1308.13 Section 1308.13 Public...criteria: Visual impairment including blindness. (a) A child is classified as...vision loss meets the definition of legal blindness in the State of residence; or...

  20. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...criteria: Visual impairment including blindness. 1308.13 Section 1308.13 Public...criteria: Visual impairment including blindness. (a) A child is classified as...vision loss meets the definition of legal blindness in the State of residence; or...

  1. 45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...criteria: Visual impairment including blindness. 1308.13 Section 1308.13 Public...criteria: Visual impairment including blindness. (a) A child is classified as...vision loss meets the definition of legal blindness in the State of residence; or...

  2. Giovanni Schiaparelli: Visions of a colour blind astronomer

    NASA Astrophysics Data System (ADS)

    Sheehan, W.

    1997-02-01

    The greatest observer of Mars of the nineteenth century was the Italian astronomer Giovanni Virginio Schiaparelli. In his classic compilation of Martian observations, La Planete Mars, published in 1892, Camille Flammarion readily conceded that Schiaparelli's was 'the greatest work which has been carried out with regard to Mars,'1 while another eminent Martian, Percival Lowell, referred to the Italian astronomer alone as his Martian master ('cher maitre Martien').

  3. Genetics of colouration in birds.

    PubMed

    Roulin, Alexandre; Ducrest, Anne-Lyse

    2013-01-01

    Establishing the links between phenotype and genotype is of great importance for resolving key questions about the evolution, maintenance and adaptive function of phenotypic variation. Bird colouration is one of the most studied systems to investigate the role of natural and sexual selection in the evolution of phenotypic diversity. Given the recent advances in molecular tools that allow discovering genetic polymorphisms and measuring gene and protein expression levels, it is timely to review the literature on the genetics of bird colouration. The present study shows that melanin-based colour phenotypes are often associated with mutations at melanogenic genes. Differences in melanin-based colouration are caused by switches of eumelanin to pheomelanin production or by changes in feather keratin structure, melanoblast migration and differentiation, as well as melanosome structure. Similar associations with other types of colourations are difficult to establish, because our knowledge about the molecular genetics of carotenoid-based and structural colouration is quasi inexistent. This discrepancy stems from the fact that only melanin-based colouration shows pronounced heritability estimates, i.e. the resemblance between related individuals is usually mainly explained by genetic factors. In contrast, the expression of carotenoid-based colouration is phenotypically plastic with a high sensitivity to variation in environmental conditions. It therefore appears that melanin-based colour traits are prime systems to understand the genetic basis of phenotypic variation. In this context, birds have a great potential to bring us to new frontiers where many exciting discoveries will be made on the genetics of phenotypic traits, such as colouration. In this context, a major goal of our review is to suggest a number of exciting future avenues. PMID:23665152

  4. Communication in coral reef fish: the role of ultraviolet colour patterns in damselfish territorial behaviour

    Microsoft Academic Search

    Ulrike E. Siebeck

    2004-01-01

    Many coral reef fish possess ultraviolet (UV) colour patterns. The behavioural significance of these patterns is poorly understood and experiments on this issue have not been reported for free-living reef fish in their natural environment. The damselfish Pomacentrus amboinensis has UV facial patterns, and spectroradiometric ocular media measurements show that it has the potential for UV vision. To test the

  5. 21 CFR 886.5900 - Electronic vision aid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...has impaired vision or blindness to translate visual images of objects into tactile or auditory signals. (b) Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of...

  6. Training Visions

    ERIC Educational Resources Information Center

    Training, 2011

    2011-01-01

    In this article, "Training" asks the 2011 winners to give their predictions for what training--either in general or specifically at their companies--will look like in the next five to 10 years. Perhaps their "training visions" will spark some ideas in one's organization--or at least help prepare for what might be coming in the next decade or so.

  7. Active vision

    Microsoft Academic Search

    John Aloimonos; Isaac Weiss; Amit Bandyopadhyay

    1988-01-01

    We investigate several basic problems in vision under the assumption that the observer is active. An observer is called active when engaged in some kind of activity whose purpose is to control the geometric parameters of the sensory apparatus. The purpose of the activity is to manipulate the constraints underlying the observed phenomena in order to improve the quality of

  8. Visions 2001.

    ERIC Educational Resources Information Center

    Rivero, Victor; Norman, Michele

    2001-01-01

    Reports on the views of 18 educational leaders regarding their vision on the future of education in an information age. Topics include people's diverse needs; relationships between morality, ethics, values, and technology; leadership; parental involvement; online courses from multiple higher education institutions; teachers' role; technology…

  9. Adolescents with Low Vision: Perceptions of Driving and Nondriving

    ERIC Educational Resources Information Center

    Sacks, Sharon Zell; Rosenblum, L. Penny

    2006-01-01

    Two studies examined how adolescents with low vision perceive their ability to drive. The results of both studies indicated similarities in the participants' responses with respect to knowledge of visual impairment, information about options for driving with low vision, frustrations and obstacles imposed by not being able to drive, and independent…

  10. Physiology and Psychology of Vision and Its Disorders: A Review

    PubMed Central

    Moschos, Marilita M

    2014-01-01

    The purpose of this review is to bring together to the physiology and psychology of vision and to analyze, based on our own data and on the available literature, the relationship between sight loss and individual reactions. As recent treatments for depression are often effective and have few side-effects, ophthalmologists should consider referral for treatment of depression in patients suffering from vision impairment. For this reason, vision rehabilitation should be more readily available and recommended. PMID:25741524

  11. The colours of extant mammals.

    PubMed

    Caro, Tim

    2013-01-01

    In this review I survey pelage and skin colouration patterns of the 29 orders of extant mammals and assess their functional significance. The vast majority of mammals are shades of grey or brown. Concealment is probably the principal evolutionary driver of pelage colouration in this Class likely through background matching and self-shadow concealment. A small minority of species are aposematic while many others have distinctive markings used in intraspecific and interspecific communication although the meaning of these markings is unclear. Colouration in mammals also has physiological consequences but these are barely understood as yet. PMID:23567208

  12. Spectral sensitivities of photoreceptors and their role in colour discrimination in the green-backed firecrown hummingbird ( Sephanoides sephaniodes )

    Microsoft Academic Search

    Gonzalo Herrera; Juan Cristóbal Zagal; Marcelo Diaz; Maria José Fernández; Alex Vielma; Michel Cure; Jaime Martinez; Francisco Bozinovic; Adrián G. Palacios

    2008-01-01

    We studied the photopic spectral sensitivity in the green-backed firecrown, Sephanoides sephaniodes, a South American hummingbird, and its possible ecological relationship with preferred flowers and body colouration. Avian\\u000a colour vision is in general tetrachromatic with at least four types of cones, which vary in sensitivity from the near ultraviolet\\u000a (UV) to the red wavelength range. Hummingbirds represent an important family

  13. Computer vision

    SciTech Connect

    Not Available

    1982-01-01

    This paper discusses material from areas such as artificial intelligence, psychology, computer graphics, and image processing. The intent is to assemble a selection of this material in a form that will serve both as a senior/graduate-level academic text and as a useful reference to those building vision systems. This book has a strong artificial intelligence flavour, emphasising the belief that both the intrinsic image information and the internal model of the world are important in successful vision systems. The book is organised into four parts, based on descriptions of objects at four different levels of abstraction. These are: generalised images-images and image-like entities; segmented images-images organised into subimages that are likely to correspond to interesting objects; geometric structures-quantitative models of image and world structures; relational structures-complex symbolic descriptions of image and world structures. The book contains author and subject indexes.

  14. Upconversion nanocrystals: Bright colours ahead

    NASA Astrophysics Data System (ADS)

    Bettinelli, Marco

    2015-03-01

    Full-colour displays with high spatial resolution can be produced with properly designed upconversion nanocrystals that emit light at different wavelengths, depending on the properties of the excitation pulses.

  15. Cartesian visions.

    PubMed

    Fara, Patricia

    2008-12-01

    Few original portraits exist of René Descartes, yet his theories of vision were central to Enlightenment thought. French philosophers combined his emphasis on sight with the English approach of insisting that ideas are not innate, but must be built up from experience. In particular, Denis Diderot criticised Descartes's views by describing how Nicholas Saunderson--a blind physics professor at Cambridge--relied on touch. Diderot also made Saunderson the mouthpiece for some heretical arguments against the existence of God. PMID:18986706

  16. Learning to Look: A Handbook for Parents of Low Vision Infants and Young Children.

    ERIC Educational Resources Information Center

    Heiner, Donna

    Specific and understandable suggestions are offered to parents of severely visually impaired children who have or may have the capacity to learn visually. Parents can assist children with even a small amount of vision to develop that vision from an early age. Vision development begins by ensuring that the child receives appropriate medical and…

  17. Wearable Mobility Aid for Low Vision Using Scene Classification in a Markov Random Field Model

    E-print Network

    Everingham, Mark

    Wearable Mobility Aid for Low Vision Using Scene Classification in a Markov Random Field Model to vision enhancement for people with severe visual impairments. This approach utilizes computer vision. The scene classifi- cation technique uses an artificial neural network classifier within the framework

  18. Colour as visual rhetoric in financial reporting

    Microsoft Academic Search

    John K. Courtis

    2004-01-01

    Visual rhetoric within communication seeks to persuade through the use of picturing and encompasses words and colour. Visual rhetoric is present within annual reports. The specific role of colour in financial reporting is a neglected field of enquiry. A survey of 100 Hong Kong annual reports related colour usage to profitability change and found companies used more colour when profitability

  19. Colour preferences of flower-naive honeybees

    Microsoft Academic Search

    M. Giurfa; J. Núñez; L. Chittka; R. Menzel

    1995-01-01

    Flower-naive honeybees Apis mellifera L. flying in an enclosure were tested for their colour preferences. Bees were rewarded once on an achromatic (grey, aluminium or hardboard), or on a chromatic (ultraviolet) disk. Since naive bees never alighted on colour stimuli alone, a scent was given in combination with colour. Their landings on twelve colour stimuli were recorded. Results after one

  20. Sexual colouration and sperm traits in guppies

    Microsoft Academic Search

    T. E. Pitcher; F. H. Rodd; L. Rowe

    2007-01-01

    The relationships among the area, hue, saturation and brightness of orange colouration and sperm traits in the guppy Poecilia reticulata were investigated. Males with greater areas of orange colouration had significantly larger sperm loads, more motile sperm and longer sperm relative to males with relatively little orange colouration. Males with greater areas of orange colouration did not possess more viable

  1. Virtual Vision

    NASA Astrophysics Data System (ADS)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  2. What Colour Is a Shadow?

    ERIC Educational Resources Information Center

    Hughes, S. W.

    2009-01-01

    What colour is a shadow? Black, grey, or some other colour? This article describes how to use a digital camera to test the hypothesis that a shadow under a clear blue sky has a blue tint. A white sheet of A4 paper was photographed in full sunlight and in shadow under a clear blue sky. The images were analysed using a shareware program called…

  3. The Secret World of Shrimps: Polarisation Vision at Its Best

    PubMed Central

    Kleinlogel, Sonja; White, Andrew G.

    2008-01-01

    Background Animal vision spans a great range of complexity, with systems evolving to detect variations in light intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. Methodology/Principal Findings Polarisation is fully measured via Stokes' parameters—obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes' parameters: here we show that the crustacean Gonodactylus smithii measures the exact components required. Conclusions/Significance This vision provides optimal contrast-enhancement and precise determination of polarisation with no confusion states or neutral points—significant advantages. Linear and circular polarisation each give partial information about the polarisation of light—but the combination of the two, as we will show here, results in optimal polarisation vision. We suggest that linear and circular polarisation vision not be regarded as different modalities, since both are necessary for optimal polarisation vision; their combination renders polarisation vision independent of strongly linearly or circularly polarised features in the animal's environment. PMID:18478095

  4. Vision Therapy News Backgrounder.

    ERIC Educational Resources Information Center

    American Optometric Association, St. Louis, MO.

    The booklet provides an overview on vision therapy to aid writers, editors, and broadcasters help parents, teachers, older adults, and all consumers learn more about vision therapy. Following a description of vision therapy or vision training, information is provided on how and why vision therapy works. Additional sections address providers of…

  5. The perception of isoluminant coloured stimuli of amblyopic eye and defocused eye

    NASA Astrophysics Data System (ADS)

    Krumina, Gunta; Ozolinsh, Maris; Ikaunieks, Gatis

    2008-09-01

    In routine eye examination the visual acuity usually is determined using standard charts with black letters on a white background, however contrast and colour are important characteristics of visual perception. The purpose of research was to study the perception of isoluminant coloured stimuli in the cases of true and simulated amlyopia. We estimated difference in visual acuity with isoluminant coloured stimuli comparing to that for high contrast black-white stimuli for true amblyopia and simulated amblyopia. Tests were generated on computer screen. Visual acuity was detected using different charts in two ways: standard achromatic stimuli (black symbols on a white background) and isoluminant coloured stimuli (white symbols on a yellow background, grey symbols on blue, green or red background). Thus isoluminant tests had colour contrast only but had no luminance contrast. Visual acuity evaluated with the standard method and colour tests were studied for subjects with good visual acuity, if necessary using the best vision correction. The same was performed for subjects with defocused eye and with true amblyopia. Defocus was realized with optical lenses placed in front of the normal eye. The obtained results applying the isoluminant colour charts revealed worsening of the visual acuity comparing with the visual acuity estimated with a standard high contrast method (black symbols on a white background).

  6. The Social Lives of Canadian Youths with Visual Impairments

    ERIC Educational Resources Information Center

    Gold, Deborah; Shaw, Alexander; Wolffe, Karen

    2010-01-01

    This survey of the social and leisure experiences of Canadian youths with visual impairments found that, in general, youths with low vision experienced more social challenges than did their peers who were blind. Levels of social support were not found to differ on the basis of level of vision, sex, or age. (Contains 1 figure and 1 table.)

  7. Filtering and polychromatic vision in mantis shrimps: themes in visible and ultraviolet vision

    PubMed Central

    Cronin, Thomas W.; Bok, Michael J.; Marshall, N. Justin; Caldwell, Roy L.

    2014-01-01

    Stomatopod crustaceans have the most complex and diverse assortment of retinal photoreceptors of any animals, with 16 functional classes. The receptor classes are subdivided into sets responsible for ultraviolet vision, spatial vision, colour vision and polarization vision. Many of these receptor classes are spectrally tuned by filtering pigments located in photoreceptors or overlying optical elements. At visible wavelengths, carotenoproteins or similar substances are packed into vesicles used either as serial, intrarhabdomal filters or lateral filters. A single retina may contain a diversity of these filtering pigments paired with specific photoreceptors, and the pigments used vary between and within species both taxonomically and ecologically. Ultraviolet-filtering pigments in the crystalline cones serve to tune ultraviolet vision in these animals as well, and some ultraviolet receptors themselves act as birefringent filters to enable circular polarization vision. Stomatopods have reached an evolutionary extreme in their use of filter mechanisms to tune photoreception to habitat and behaviour, allowing them to extend the spectral range of their vision both deeper into the ultraviolet and further into the red. PMID:24395960

  8. Taste - impaired

    MedlinePLUS

    ... longer. Causes of impaired taste include: Bell's palsy Common cold Flu Nasal infection, nasal polyps , sinusitis Pharyngitis and ... your diet. For taste problems due to the common cold or flu, normal taste should return when the ...

  9. Impaired Driving

    MedlinePLUS

    ... 08% or greater. 1 Nearly half of the alcohol-impaired motorcyclists killed each year are age 40 or older, and motorcyclists ages 40-44 have the highest percentage of deaths with BACs of 0.08% or ...

  10. Extrasolar Visions

    NSDL National Science Digital Library

    The Extrasolar Visions Web site provides a searchable guide to extra solar planets. These include planets of normal stars, pulsar planets, brown dwarfs, protoplanetary disks and protoplanets, extragalactic worlds, massive compact halo objects, and disproven or doubtful worlds. Visitors can search for these objects or view the week's 20 most popular systems, 20 most interesting systems, or the 20 most recently updated systems. Once chosen, the objects name, mass, average distance, and type is given along with a link for further information. This well designed site does a good job of combining quality information and graphics resulting in a pleasurable surfing experience for anyone exploring it.

  11. Background colour matching by a crab spider in the field: a community sensory ecology perspective.

    PubMed

    Defrize, Jérémy; Théry, Marc; Casas, Jérôme

    2010-05-01

    The question of whether a species matches the colour of its natural background in the perspective of the correct receiver is complex to address for several reasons; however, the answer to this question may provide invaluable support for functional interpretations of colour. In most cases, little is known about the identity and visual sensory abilities of the correct receiver and the precise location at which interactions take place in the field, in particular for mimetic systems. In this study, we focused on Misumena vatia, a crab spider meeting the criteria for assessing crypsis better than many other models, and claimed to use colour changes for both aggressive and protective crypsis. We carried out a systematic field survey to quantitatively assess the exactness of background colour matching in M. vatia with respect to the visual system of many of its receivers within the community. We applied physiological models of bird, bee and blowfly colour vision, using flower and spider spectral reflectances measured with a spectroradiometer. We observed that crypsis at long distance is systematically achieved, exclusively through achromatic contrast, in both bee and bird visions. At short distance, M. vatia is mostly chromatically detectable, whatever the substrate, for bees and birds. However, spiders can be either poorly discriminable or quite visible depending on the substrate for bees. Spiders are always chromatically undetectable for blowflies. We discuss the biological relevance of these results in both defensive and aggressive contexts of crypsis within a community sensory perspective. PMID:20400626

  12. Raven's Coloured Progressive Matrices as a Measure of Cognitive Functioning in Cerebral Palsy

    ERIC Educational Resources Information Center

    Pueyo, R.; Junque, C.; Vendrell, P.; Narberhaus, A.; Segarra, D.

    2008-01-01

    Background: Cognitive dysfunction is frequent in Cerebral Palsy (CP). CP motor impairment and associated speech deficits often hinder cognitive assessment, with the result being that not all CP studies consider cognitive dysfunction. Raven's Coloured Progressive Matrices is a simple, rapid test which can be used in persons with severe motor…

  13. The Colours of HII Galaxies

    E-print Network

    Eduardo Telles; Roberto Terlevich

    1995-11-21

    We present high spatial resolution CCD surface photometry study in the optical V, R and I filters of 15 HII galaxies from the Nordic Optical Telescope and the Jacobus Kapteyn Telescope at Canary Islands. The colours of the starburst continuum and of the underlying galaxy are measured. The distribution of colours of the underlying galaxy in HII galaxies is similar to the colours of other late type low surface brightness galaxies which suggests a close kinship of these with the quiescent phases of HII galaxies. However, comparison with recent evolutionary population synthesis models show that the observational errors and the uncertainties in the models are still too large to put strict constraints on their past star formation history.

  14. Methods for describing illumination colour uniformities

    NASA Astrophysics Data System (ADS)

    Rotscholl, Ingo; Trampert, Klaus; Herrmann, Franziska; Neumann, Cornelius

    2015-02-01

    Optimizing angular or spatial colour homogeneity has become an important task in many general lighting applications and first requires a valid description of illumination colour homogeneity. We analyse different frequently used methods to describe colour distributions in theory and with measurement data. It is described why information about chromaticity coordinates, correlated colour temperature and global chromaticity coordinate distances are not sufficient for describing colour homogeneity perception of light distributions. We present local chromaticity coordinate distances as expandable and easy implementable method for describing colour homogeneity distributions that is adaptable to the field of view by only one intuitive, physiological meaningful parameter.

  15. Animat Vision - Active Vision in Artificial Animals

    Microsoft Academic Search

    Tamer F. Rabie

    1999-01-01

    We propose and demonstrate a new paradigm for active vision research which draws upon recent advances in the fields of artificial life and computer graphics. A software alternative to the prevailing hardware vision mindset, animat vision prescribes artificial animals, or animats, situated in physics-based virtual worlds as autonomous virtual robots with active perception systems. To be operative in its world,

  16. Animat Vision: Active Vision in Artificial Animals

    Microsoft Academic Search

    Demetri Terzopoulos; Tamer F. Rabie

    1995-01-01

    We propose and demonstrate a new paradigm for active vision r e- search that draws upon recent advances in the fields of artific ial life and computer graphics. A software alternative to the pr evailing hardware vision mindset, animat vision prescribes artifici al animals, or animats, situated in physics-based virtual worlds as aut onomous virtual robots possessing active perception systems.

  17. Cell Phone Accessibility (for the Visually Impaired)

    MedlinePLUS

    ... Text of Section 255 Back to : Using Technology Directory of Services Find Local Services: Browse Services Featured ... Family of Sites FamilyConnect ® CareerConnect ® VisionAware ™ Braille Bug ® Directory Center AccessWorld ® Journal of Visual Impairment & Blindness Center ...

  18. Ecological genomics in full colour.

    PubMed

    Hohenlohe, Paul A

    2014-11-01

    Colour patterns in animals have long offered an opportunity to observe adaptive traits in natural populations. Colour plays myriad roles in interactions within and among species, from reproductive signalling to predator avoidance, leading to multiple targets of natural and sexual selection and opportunities for diversification. Understanding the genetic and developmental underpinnings of variation in colour promises a fuller understanding of these evolutionary processes, but the path to unravelling these connections can be arduous. The advent of genomic techniques suitable for nonmodel organisms is now beginning to light the way. Two new studies in this issue of Molecular Ecology use genomic sequencing of laboratory crosses to map colour traits in cichlid fishes, a remarkably diverse group in which coloration has played a major role in diversification. They illustrate how genomic approaches, specifically RAD sequencing, can rapidly identify both simple and more complex genetic variation underlying ecologically important traits. In the first, Henning et al. () detect a single locus that appears to control in a Mendelian fashion the presence of horizontal stripes, a trait that has evolved in numerous cichlid lineages. In the second, Albertson et al. () identify several genes and epistatic interactions affecting multiple colour traits, as well as a novel metric describing integration across colour traits. Albertson et al. () go further, by quantifying differential expression of parental alleles at a candidate locus and by relating differentiation among natural populations at mapped loci to trait divergence. Herein lies the promise of ecological genomics - efficiently integrating genetic mapping of phenotypes with population genomic data to both identify functional genes and unravel their evolutionary history. These studies offer guidance on how genomic techniques can be tailored to a research question or study system, and they also add to the growing body of empirical examples addressing basic questions about how ecologically important traits evolve in natural populations. PMID:25330852

  19. Colour Appearance and Colour Rendering of HDR Scenes: An Experiment

    Microsoft Academic Search

    Carinna Parraman; Alessandro Rizzi; John J. McCannc

    In order to gain a deeper understanding of the appearance of coloured objects in a three-dimensional scene, the research introduces a multidisciplinary experimental approach. The experiment employed two identical 3-D Mondrians, which were viewed and compared side by side. Each scene was subjected to different lighting conditions. First, we used an illumination cube to diffuse the light and illuminate all

  20. Colour Spaces for Colour Transfer Erik Reinhard and Tania Pouli

    E-print Network

    Reinhard, Erik

    , Correlation 1 Introduction Colour is one of the main image attributes used in art, photography and visuali of that reference. In essence this operation can be seen as a function that, given two images, produces a third to decorrelate its input. Wh

  1. Physical Impairment

    NASA Astrophysics Data System (ADS)

    Trewin, Shari

    Many health conditions can lead to physical impairments that impact computer and Web access. Musculoskeletal conditions such as arthritis and cumulative trauma disorders can make movement stiff and painful. Movement disorders such as tremor, Parkinsonism and dystonia affect the ability to control movement, or to prevent unwanted movements. Often, the same underlying health condition also has sensory or cognitive effects. People with dexterity impairments may use a standard keyboard and mouse, or any of a wide range of alternative input mechanisms. Examples are given of the diverse ways that specific dexterity impairments and input mechanisms affect the fundamental actions of Web browsing. As the Web becomes increasingly sophisticated, and physically demanding, new access features at the Web browser and page level will be necessary.

  2. Colour As a Signal for Entraining the Mammalian Circadian Clock

    PubMed Central

    Walmsley, Lauren; Hanna, Lydia; Mouland, Josh; Martial, Franck; West, Alexander; Smedley, Andrew R.; Bechtold, David A.; Webb, Ann R.; Lucas, Robert J.; Brown, Timothy M.

    2015-01-01

    Twilight is characterised by changes in both quantity (“irradiance”) and quality (“colour”) of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue–yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision. PMID:25884537

  3. Colour as a signal for entraining the Mammalian circadian clock.

    PubMed

    Walmsley, Lauren; Hanna, Lydia; Mouland, Josh; Martial, Franck; West, Alexander; Smedley, Andrew R; Bechtold, David A; Webb, Ann R; Lucas, Robert J; Brown, Timothy M

    2015-04-01

    Twilight is characterised by changes in both quantity ("irradiance") and quality ("colour") of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue-yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision. PMID:25884537

  4. Vision Screening

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Visi Screen OSS-C, marketed by Vision Research Corporation, incorporates image processing technology originally developed by Marshall Space Flight Center. Its advantage in eye screening is speed. Because it requires no response from a subject, it can be used to detect eye problems in very young children. An electronic flash from a 35 millimeter camera sends light into a child's eyes, which is reflected back to the camera lens. The photorefractor then analyzes the retinal reflexes generated and produces an image of the child's eyes, which enables a trained observer to identify any defects. The device is used by pediatricians, day care centers and civic organizations that concentrate on children with special needs.

  5. Robot Vision

    NASA Technical Reports Server (NTRS)

    Sutro, L. L.; Lerman, J. B.

    1973-01-01

    The operation of a system is described that is built both to model the vision of primate animals, including man, and serve as a pre-prototype of possible object recognition system. It was employed in a series of experiments to determine the practicability of matching left and right images of a scene to determine the range and form of objects. The experiments started with computer generated random-dot stereograms as inputs and progressed through random square stereograms to a real scene. The major problems were the elimination of spurious matches, between the left and right views, and the interpretation of ambiguous regions, on the left side of an object that can be viewed only by the left camera, and on the right side of an object that can be viewed only by the right camera.

  6. Binocular Vision

    PubMed Central

    Blake, Randolph; Wilson, Hugh

    2010-01-01

    This essay reviews major developments –empirical and theoretical –in the field of binocular vision during the last 25 years. We limit our survey primarily to work on human stereopsis, binocular rivalry and binocular contrast summation, with discussion where relevant of single-unit neurophysiology and human brain imaging. We identify several key controversies that have stimulated important work on these problems. In the case of stereopsis those controversies include position versus phase encoding of disparity, dependence of disparity limits on spatial scale, role of occlusion in binocular depth and surface perception, and motion in 3D. In the case of binocular rivalry, controversies include eye versus stimulus rivalry, role of “top-down” influences on rivalry dynamics, and the interaction of binocular rivalry and stereopsis. Concerning binocular contrast summation, the essay focuses on two representative models that highlight the evolving complexity in this field of study. PMID:20951722

  7. Hearing Impairments

    NASA Astrophysics Data System (ADS)

    Cavender, Anna; Ladner, Richard E.

    For many people with hearing impairments, the degree of hearing loss is only a small aspect of their disability and does not necessarily determine the types of accessibility solutions or accommodations that may be required. For some people, the ability to adjust the audio volume may be sufficient. For others, translation to a signed language may be more appropriate. For still others, access to text alternatives may be the best solution. Because of these differences, it is important for researchers in Web accessibility to understand that people with hearing impairments may have very different cultural-linguistic traditions and personal backgrounds.

  8. Positive emotion can protect against source memory impairment.

    PubMed

    MacKenzie, Graham; Powell, Tim F; Donaldson, David I

    2015-01-01

    Despite widespread belief that memory is enhanced by emotion, evidence also suggests that emotion can impair memory. Here we test predictions inspired by object-based binding theory, which states that memory enhancement or impairment depends on the nature of the information to be retrieved. We investigated emotional memory in the context of source retrieval, using images of scenes that were negative, neutral or positive in valence. At study each scene was paired with a colour and during retrieval participants reported the source colour for recognised scenes. Critically, we isolated effects of valence by equating stimulus arousal across conditions. In Experiment 1 colour borders surrounded scenes at study: memory impairment was found for both negative and positive scenes. Experiment 2 used colours superimposed over scenes at study: valence affected source retrieval, with memory impairment for negative scenes only. These findings challenge current theories of emotional memory by showing that emotion can impair memory for both intrinsic and extrinsic source information, even when arousal is equated between emotional and neutral stimuli, and by dissociating the effects of positive and negative emotion on episodic memory retrieval. PMID:24784151

  9. International computer vision directory

    SciTech Connect

    Flora, P.C.

    1986-01-01

    This book contains information on: computerized automation technologies. State-of-the-art computer vision systems for many areas of industrial use are covered. Other topics discussed include the following automated inspection systems; robot/vision systems; vision process control; cameras (vidicon and solid state); vision peripherals and components; and pattern processor.

  10. All about Low Vision

    MedlinePLUS

    ... About Low Vision & Blindness > All About Low Vision All About Low Vision Due to an increase in the number of aging baby boomers and the growing ... sensitivity, a significantly obstructed field of vision -- or all three. Watch simulations of some of the most ...

  11. The Colour of Butterflies' Wings

    Microsoft Academic Search

    F. E. v

    1870-01-01

    IN making some experiments a short time ago, I came across a fact of which I was hitherto ignorant. I wished to test the effect of acid on the colours of the wings of a butterfly or moth, and with this view applied muriatic acid to a dried and set specimen of the Six-spotted Burnet [Zygæna filipendulæ). The red parts

  12. Segmentation of Colour Layers in Historical Maps Based on Hierarchical Colour Sampling

    NASA Astrophysics Data System (ADS)

    Leyk, Stefan

    A colour image segmentation (CIS) process for scanned historical maps is presented to overcome common problems associated with segmentation of old documents such as (1) variation in colour values of the same colour layer within one map page, (2) differences in typical colour values between homogeneous areas and thin line-work, which belong both to the same colour layer, and (3) extensive parameterization that results in a lack of robustness. The described approach is based on a two-stage colour layer prototype search using a constrained sampling design. Global colour layer prototypes for the identification of homogeneous regions are derived based on colour similarity to the most extreme colour layer values identified in the map page. These global colour layer prototypes are continuously adjusted using relative distances between prototype positions in colour space until a reliable sample is collected. Based on this sample colour layer seeds and directly connected neighbors of the same colour layer are determined resulting in the extraction of homogeneous colour layer regions. In the next step the global colour layer prototypes are recomputed using a new sample of colour values along the margins of identified homogeneous coloured regions. This sampling step derives representative prototypes of map layer sections that deviate significantly from homogeneous regions of the same layers due to bleaching, mixed or false colouring and ageing of the original scanned documents. A spatial expansion process uses these adjusted prototypes as start criterion to assign the remaining colour layer parts. The approach shows high robustness for map documents that suffer from low graphical quality indicating some potential for general applicability due to its simplicity and the limited need for preliminary information. The only input required is the colours and number of colour layers present in the map.

  13. Search for colour singlet and colour reconnection effects in hadronic Z decays at LEP

    NASA Astrophysics Data System (ADS)

    Achard, P.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; van Dalen, J. A.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Guida, M.; van Gulik, R.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Hu, Y.; Jin, B. N.; Jones, L. W.; de Jong, P.; Josa-Mutuberr?´a, I.; Käfer, D.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kraemer, R. W.; Krüger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Quartieri, J.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, K.; Roe, B. P.; Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, S.; Rosenbleck, C.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tung, K. L.; Ulbricht, J.; Valente, E.; Van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, Q.; Wang, X. L.; Wang, Z. M.; Weber, M.; Wienemann, P.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yeh, S. C.; Zalite, An.; Zalite, Yu.; Zhang, Z. P.; Zhao, J.

    2004-02-01

    A search is performed in symmetric 3-jet hadronic Z-decay events for evidence of colour singlet production or colour reconnection effects. Asymmetries in the angular separation of particles are found to be sensitive indicators of such effects. Upper limits on the level of colour singlet production or of colour reconnection effects are established for a variety of models.

  14. Search for Colour Singlet and Colour Reconnection Effects in Hadronic Z Decays at LEP

    Microsoft Academic Search

    P Achard; O Adriani; M Aguilar-Benítez; J Alcaraz; G Alemanni; James V Allaby; A Aloisio; M G Alviggi; H Anderhub; V P Andreev; F Anselmo; A Arefev; T Azemoon; T Aziz; P Bagnaia; A Bajo; G Baksay; L Baksay; S V Baldew; S Banerjee; A Barczyk; R Barillère; P Bartalini; M Basile; N Batalova; R Battiston; A Bay; F Becattini; U Becker; F Behner; L Bellucci; R Berbeco; J Berdugo; P Berges; B Bertucci; B L Betev; M Biasini; M Biglietti; A Biland; J J Blaising; S C Blyth; Gerjan J Bobbink; A Böhm; L Boldizsar; B Borgia; S Bottai; D Bourilkov; Maurice Bourquin; S Braccini; J G Branson; F Brochu; J D Burger; W J Burger; X D Cai; M Capell; G Cara Romeo; G Carlino; A M Cartacci; J Casaus; F Cavallari; N Cavallo; C Cecchi; M Cerrada; M Chamizo-Llatas; Y H Chang; M Chemarin; A Chen; G Chen; H F Chen; H S Chen; G Chiefari; Luisa Cifarelli; F Cindolo; I Clare; R Clare; G Coignet; N Colino; S Costantini; B de la Cruz; S Cucciarelli; J A van Dalen; R De Asmundis; P L Déglon; J Debreczeni; A Degré; K Dehmelt; K Deiters; D Della Volpe; E Delmeire; P Denes; F De Notaristefani; A De Salvo; M Diemoz; M Dierckxsens; C Dionisi; M Dittmar; A Doria; M T Dova; D Duchesneau; M Duda; B Echenard; A Eline; A El-Hage; H El-Mamouni; A Engler; F J Eppling; P Extermann; M A Falagán; S Falciano; A Favara; J Fay; O Fedin; M Felcini; T Ferguson; H S Fesefeldt; E Fiandrini; J H Field; F Filthaut; P H Fisher; W Fisher; I Fisk; G Forconi; Klaus Freudenreich; C Furetta; Yu Galaktionov; S N Ganguli; P García-Abia; M Gataullin; S Gentile; S Giagu; Z F Gong; G Grenier; O Grimm; M W Grünewald; M Guida; R van Gulik; V K Gupta; A Gurtu; L J Gutay; D Haas; D Hatzifotiadou; T Hebbeker; A Hervé; J Hirschfelder; H Hofer; M Hohlmann; G Holzner; S R Hou; Y Hu; B N Jin; L W Jones; P de Jong; I Josa-Mutuberria; D Käfer; M Kaur; M N Kienzle-Focacci; J K Kim; Jasper Kirkby; E W Kittel; A Klimentov; A C König; M Kopal; V F Koutsenko; M H Kräber; R W Krämer; A Krüger; A Kunin; P Ladrón de Guevara; I Laktineh; G Landi; M Lebeau; A Lebedev; P Lebrun; P Lecomte; P Lecoq; P Le Coultre; J M Le Goff; R Leiste; M Levtchenko; P M Levchenko; C Li; S Likhoded; C H Lin; W T Lin; Frank L Linde; L Lista; Z A Liu; W Lohmann; E Longo; Y S Lü; C Luci; L Luminari; W Lustermann; Ma Wen Gan; L Malgeri; A Malinin; C Maña; J Mans; J P Martin; F Marzano; K Mazumdar; R R McNeil; S Mele; L Merola; M Meschini; W J Metzger; A Mihul; H Milcent; G Mirabelli; J Mnich; G B Mohanty; G S Muanza; A J M Muijs; B Musicar; M Musy; S Nagy; S Natale; M Napolitano; F Nessi-Tedaldi; H Newman; A Nisati; T Novák; H Nowak; R A Ofierzynski; G Organtini; I Pal; C Palomares; P Paolucci; R Paramatti; G Passaleva; S Patricelli; T Paul; M Pauluzzi; C Paus; Felicitas Pauss; M Pedace; S Pensotti; D Perret-Gallix; B Petersen; D Piccolo; F Pierella; M Pioppi; P A Piroué; E Pistolesi; V Plyaskin; M Pohl; V Pozhidaev; J Pothier; D Prokofev; D O Prokofiev; J Quartieri; G Rahal-Callot; M A Rahaman; P Raics; N Raja; R Ramelli; P G Rancoita; R Ranieri; A V Raspereza; P A Razis; D Ren; M Rescigno; S Reucroft; S Riemann; K Riles; B P Roe; L Romero; A Rosca; S Rosier-Lees; S Roth; C Rosenbleck; J A Rubio; G Ruggiero; H Rykaczewski; A Sakharov; S Saremi; S Sarkar; J Salicio; E Sánchez; C Schäfer; V Shchegelskii; Herwig Franz Schopper; D J Schotanus; C Sciacca; L Servoli; S Shevchenko; N Shivarov; V Shoutko; E Shumilov; A V Shvorob; D Son; C Souga; P Spillantini; M Steuer; D P Stickland; B Stoyanov; A Strässner; K Sudhakar; G G Sultanov; L Z Sun; S Sushkov; H Suter; J D Swain; Z Szillási; X W Tang; P Tarjan; Ludwig Tauscher; L Taylor; B Tellili; D Teyssier; C Timmermans; Samuel C C Ting; S M Ting; S C Tonwar; J Tóth; C Tully; K L Tung; J Ulbricht; E Valente; R T Van de Walle; R Vásquez; V Veszpremi; G Vesztergombi; I Vetlitskii; D Vicinanza; Gert M Viertel; S Villa; M Vivargent; S Vlachos; I Vodopyanov; H Vogel; H Vogt; I Vorobev; A A Vorobyov; M Wadhwa; Q Wang; X L Wang; Z M Wang; M Weber; P Wienemann; H Wilkens; S Wynhoff; L Xia; Z Z Xu; J Yamamoto; B Z Yang; C G Yang; H J Yang; M Yang; S C Yeh; A Zalite; Yu Zalite; Z P Zhang; J Zhao; G Y Zhu; R Y Zhu; H L Zhuang; A Zichichi; B Zimmermann; M Zöller

    2003-01-01

    A search is performed in symmetric 3-jet hadronic Z decay events for evidence of colour singlet production or colour reconnection effects. Asymmetries in the angular separation of particles are found to be sensitive indicators of such effects. Upper limits on the level of colour singlet production and colour reconnection effects are established for a variety of models.

  15. (Computer vision and robotics)

    SciTech Connect

    Jones, J.P.

    1989-02-13

    The traveler attended the Fourth Aalborg International Symposium on Computer Vision at Aalborg University, Aalborg, Denmark. The traveler presented three invited lectures entitled, Concurrent Computer Vision on a Hypercube Multicomputer'', The Butterfly Accumulator and its Application in Concurrent Computer Vision on Hypercube Multicomputers'', and Concurrency in Mobile Robotics at ORNL'', and a ten-minute editorial entitled, It Concurrency an Issue in Computer Vision.'' The traveler obtained information on current R D efforts elsewhere in concurrent computer vision.

  16. Colour model analysis for microscopic image processing

    Microsoft Academic Search

    Gloria Bueno; Roberto González; Oscar Déniz; Jesús González; Marcial García-Rojo

    2000-01-01

    Aims: This article presents a comparative study between different colour models (RGB, HSI and CIEL*a*b*) applied to very large microscopic image analysis. Such analysis of different colour models is needed in order to carry out a successful detection and therefore a classification of different regions of interest (ROIs) with- in the image. Methods: All colour models have their advantages and

  17. Biological Components of Colour Preference in Infancy

    ERIC Educational Resources Information Center

    Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

    2010-01-01

    Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

  18. Colour space models for soil science

    Microsoft Academic Search

    R. A. Viscarra Rossel; B. Minasny; P. Roudier; A. B. McBratney

    2006-01-01

    Soil colour is an important soil property. It is frequently used by soil scientists for the identification and classification of soil. It is also used as an indicator of field soil physical, chemical and biological properties as well as of the occurrence of soil processes. Measurements of soil colour are commonly made using the Munsell soil colour charts. A number

  19. An RGB Approach to Prismatic Colours

    ERIC Educational Resources Information Center

    Theilmann, Florian; Grusche, Sascha

    2013-01-01

    Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

  20. Characters with Visual Impairment: Looking at Books for Young Adults through Their Eyes.

    ERIC Educational Resources Information Center

    Carroll, Pamela S.; Rosenblum, L. Penny

    A study that joined the fields of young adult literature and vision impairment explored the questions: How are characters who have visual impairment presented by young adult books?; and How do readers respond to those characters? Only a few books were found (13) that feature characters with visual impairments, and the portrayal of characters…

  1. American Visions

    NSDL National Science Digital Library

    American Visions is the companion site to an eight-week PBS series of the same name that runs from May 28 to June 18, 1997. It "tells the history of America's people and places through its art"; this guided tour is conducted by veteran Time magazine art critic Robert Hughes. The site is highlighted by the Exhibition section, a collection of Shockwave-based interactive photo essays on American art history (images and commentary accompanying the first two episodes are available at this time). Each exhibit contains an overall commentary section, as well as specific commentary or quotes for selected images (visible when the mouse pointer moves over the multi-colored bullets that accompany the images). The pages of each exhibit can be navigated from the bottom frame. There is also a large "art gallery" of over 100 images from the series, a series synopsis, and a "remote control" web tour (a separate pop-up window) of sites related to the series. It is a beautiful, though extremely browser and graphics intensive, site.

  2. Colour and odour drive fruit selection and seed dispersal by mouse lemurs

    PubMed Central

    Valenta, Kim; Burke, Ryan J.; Styler, Sarah A.; Jackson, Derek A.; Melin, Amanda D.; Lehman, Shawn M.

    2013-01-01

    Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by mouse lemurs. We show that both fruit colour and odour significantly predict fruit consumption and seed dispersal by Microcebus ravelobensis and M. murinus. Our study is the first to quantify and examine the role of bimodal fruit signals on seed dispersal in light of the sensory abilities of the disperser. PMID:23939534

  3. Colour dependence of zodiacal light models

    NASA Technical Reports Server (NTRS)

    Giese, R. H.; Hanner, M. S.; Leinert, C.

    1973-01-01

    Colour models of the zodiacal light in the ecliptic have been calculated for both dielectric and metallic particles in the sub-micron and micron size range. Two colour ratios were computed, a blue ratio and a red ratio. The models with a size distribution proportional to s to the -2.5 power ds (where s is the particle radius) generally show a colour close to the solar colour and almost independent of elongation. Especially in the blue colour ratio there is generally no significant dependence on the lower cutoff size (0.1-1 micron). The main feature of absorbing particles is a reddening at small elongations. The models for size distributions proportional to s to the -4 power ds show larger departures from solar colour and more variation with model parameters. Colour measurements, including red and near infra-red, therefore are useful to distinguish between flat and steep size spectra and to verify the presence of slightly absorbing particles.

  4. How Bees Discriminate a Pattern of Two Colours from Its Mirror Image

    PubMed Central

    Horridge, Adrian

    2015-01-01

    A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors. PMID:25617892

  5. How bees discriminate a pattern of two colours from its mirror image.

    PubMed

    Horridge, Adrian

    2015-01-01

    A century ago, in his study of colour vision in the honeybee (Apis mellifera), Karl von Frisch showed that bees distinguish between a disc that is half yellow, half blue, and a mirror image of the same. Although his inference of colour vision in this example has been accepted, some discrepancies have prompted a new investigation of the detection of polarity in coloured patterns. In new experiments, bees restricted to their blue and green receptors by exclusion of ultraviolet could learn patterns of this type if they displayed a difference in green contrast between the two colours. Patterns with no green contrast required an additional vertical black line as a landmark. Tests of the trained bees revealed that they had learned two inputs; a measure and the retinotopic position of blue with large field tonic detectors, and the measure and position of a vertical edge or line with small-field phasic green detectors. The angle between these two was measured. This simple combination was detected wherever it occurred in many patterns, fitting the definition of an algorithm, which is defined as a method of processing data. As long as they excited blue receptors, colours could be any colour to human eyes, even white. The blue area cue could be separated from the green receptor modulation by as much as 50°. When some blue content was not available, the bees learned two measures of the modulation of the green receptors at widely separated vertical edges, and the angle between them. There was no evidence that the bees reconstructed the lay-out of the pattern or detected a tonic input to the green receptors. PMID:25617892

  6. Matrix models and graph colouring

    NASA Astrophysics Data System (ADS)

    Cicuta, Giovanni M.; Molinari, Luca; Montaldi, Emilio

    1993-06-01

    We study an edge-colouring problem on random planar graphs which is one of the simplest vertex models that may be analyzed by standard methods of large N matrix models. The main features of the saddle point solution and its critical behaviour are described. At the critical value of the coupling gcr the eigen value density u(?)M is found to vanish at the border of the support as ?-a2/3.

  7. Supersymmetric strings and colour confinement

    Microsoft Academic Search

    M. Ademollo; L. Brink; A. D'Adda; R. D'Auria; E. Napolitano; S. Sciuto; E. del Giudice; P. di Vecchia; S. Ferrara; F. Gliozzi; R. Musto; R. Pettorino

    1976-01-01

    The (infinite-dimensional) supersymmetry algebra in 1 + 1 space-time dimension is extended in order to incorporate, in a non-trivial way, an internal symmetry. It turns out that this requirement implies that the internal symmetry is realized as a local gauge symmetry. Moreover, it is possible to construct string-like models with this underlying symmetry, where colour confinement is exactly realized as

  8. Colour Reconnections and Rapidity Gaps

    E-print Network

    Leif Lonnblad

    1995-12-20

    The success of recently proposed models for describing rapidity-gap events in DIS at HERA, in terms additional colour exchange between the struck system and the proton remnant in boson-gluon fusion events, are found to rely heavily on the absence or artificial suppression of perturbative gluon emission in the forward region. A model without such suppression is presented, which cannot describe the rapidity-gap events without a pomeron-inspired mechanism.

  9. Composition of a Vision Screen for Servicemembers With Traumatic Brain Injury: Consensus Using a Modified Nominal Group Technique

    PubMed Central

    Finkelstein, Marsha; Llanos, Imelda; Scheiman, Mitchell; Wagener, Sharon Gowdy

    2014-01-01

    Vision impairment is common in the first year after traumatic brain injury (TBI), including among service members whose brain injuries occurred during deployment in Iraq and Afghanistan. Occupational therapy practitioners provide routine vision screening to inform treatment planning and referral to vision specialists, but existing methods are lacking because many tests were developed for children and do not screen for vision dysfunction typical of TBI. An expert panel was charged with specifying the composition of a vision screening protocol for servicemembers with TBI. A modified nominal group technique fostered discussion and objective determinations of consensus. After considering 29 vision tests, the panel recommended a nine-test vision screening that examines functional performance, self-reported problems, far–near acuity, reading, accommodation, convergence, eye alignment and binocular vision, saccades, pursuits, and visual fields. Research is needed to develop reliable, valid, and clinically feasible vision screening protocols to identify TBI-related vision disorders in adults. PMID:25005505

  10. The original colours of fossil beetles

    PubMed Central

    McNamara, Maria E.; Briggs, Derek E. G.; Orr, Patrick J.; Noh, Heeso; Cao, Hui

    2012-01-01

    Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group. PMID:21957131

  11. Retinal Detachment Vision Simulator

    MedlinePLUS

    ... Eye Health News Consumer Alerts Retinal Detachment Vision Simulator Tweet How does a detached or torn retina ... field of vision. How do I use this simulator? Drag the slider from left to right to ...

  12. Cataract Vision Simulator

    MedlinePLUS

    ... Sun Eye Health News Consumer Alerts Cataract Vision Simulator Tweet How do cataracts affect your vision? A ... period of year. How do I use this simulator? Drag the slider from left to right to ...

  13. Computer vision on tap

    E-print Network

    Chiu, Kevin Geeyoung

    We demonstrate a concept of computer vision as a secure, live service on the Internet. We show a platform to distribute a real time vision algorithm using simple widely available Web technologies, such as Adobe Flash. We ...

  14. Vision channels, contrast sensitivity, and functional vision

    NASA Astrophysics Data System (ADS)

    Ginsburg, Arthur P.

    2004-06-01

    The neurophysiology and psychophysics of vision provide the basis for vision channels. Vision channels are the foundation of understanding spatial vision. This understanding has led to the development of a general model of visual perception and tests of functional vision. The channel model is shown to predict the Gestalt of many objects and perceptual distortions in a wide variety of spatial patterns misnamed as "visual illusions". Contrast sensitivity has been shown, more than visual acuity, to relate to functional vision and the visual quality of everyday objects viewed at work and play. The channel model and differences in contrast sensitivity help explain why people such as drivers with similar good visual acuity can complain of the quality of vision in one eye and not the other from eye disease and can dete4ct and identify objects at significatnly different distances. The peak of the contrast sensitivity function, about 3 to 6 cpd, is most sensitive to detecting objects at low contrast and is shown to relate to the visibility of a variety of objects in a night driving simulator. Using the contrast sensitivity function from sine-wave grating contrast sensitivity charts, EyeView software creates images that relate to the quality of vision.

  15. A roadmap for interpreting the literature on vision and driving.

    PubMed

    Owsley, Cynthia; Wood, Joanne M; McGwin, Gerald

    2015-01-01

    Over the past several decades there has been a sharp increase in the number of studies focused on the relationship between vision and driving. The intensified attention to this topic has most likely been stimulated by the lack of an evidence basis for determining vision standards for driving licensure and a poor understanding about how vision impairment impacts driver safety and performance. Clinicians depend on the literature on vision and driving to advise visually impaired patients appropriately about driving fitness. Policy makers also depend on the scientific literature in order to develop guidelines that are evidence-based and are thus fair to persons who are visually impaired. Thus it is important for clinicians and policy makers alike to understand how various study designs and measurement methods should be interpreted so that the conclusions and recommendations they make are not overly broad, too narrowly constrained, or even misguided. We offer a methodological framework to guide interpretations of studies on vision and driving that can also serve as a heuristic for researchers in the area. Here, we discuss research designs and general measurement methods for the study of vision as they relate to driver safety, driver performance, and driver-centered (self-reported) outcomes. PMID:25753389

  16. The multiple disguises of spiders: web colour and decorations, body colour and movement

    PubMed Central

    Théry, Marc; Casas, Jérôme

    2008-01-01

    Diverse functions have been assigned to the visual appearance of webs, spiders and web decorations, including prey attraction, predator deterrence and camouflage. Here, we review the pertinent literature, focusing on potential camouflage and mimicry. Webs are often difficult to detect in a heterogeneous visual environment. Static and dynamic web distortions are used to escape visual detection by prey, although particular silk may also attract prey. Recent work using physiological models of vision taking into account visual environments rarely supports the hypothesis of spider camouflage by decorations, but most often the prey attraction and predator confusion hypotheses. Similarly, visual modelling shows that spider coloration is effective in attracting prey but not in conveying camouflage. Camouflage through colour change might be used by particular crab spiders to hide from predator or prey on flowers of different coloration. However, results obtained on a non-cryptic crab spider suggest that an alternative function of pigmentation may be to avoid UV photodamage through the transparent cuticle. Numerous species are clearly efficient locomotory mimics of ants, particularly in the eyes of their predators. We close our paper by highlighting gaps in our knowledge. PMID:18990672

  17. Robot Vision Library

    NASA Technical Reports Server (NTRS)

    Howard, Andrew B.; Ansar, Adnan I.; Litwin, Todd E.; Goldberg, Steven B.

    2009-01-01

    The JPL Robot Vision Library (JPLV) provides real-time robot vision algorithms for developers who are not vision specialists. The package includes algorithms for stereo ranging, visual odometry and unsurveyed camera calibration, and has unique support for very wideangle lenses

  18. Artificial Vision LOGICAL ARCHITECTURE

    E-print Network

    Artificial Vision LOGICAL ARCHITECTURE Dr. Christian Micheloni Department of Computer Science Università Degli Studi di Udine Artificial Vision State of the art (2) Second Systems Generation (1990 PAGE 3 #12;2011 Prof. Micheloni Christian Università Degli Studi di Udine Artificial Vision State

  19. Artificial Vision Image Registration

    E-print Network

    Artificial Vision Image Registration Dr. Christian Micheloni Department of Computer Science. Micheloni Christian Università Degli Studi di Udine Artificial Vision Change Detection: Moving Camera Christian Università Degli Studi di Udine Artificial Vision Image Registration · The image registration

  20. Low Vision Simulations

    MedlinePLUS

    Low Vision Simulations Normal Vision A cataract is a clouding of the lens of the eye and light that passes through the lens to the ... Contrast sensitivity decreases, visual acuity drops somewhat, and vision in low light levels suffers. Home , Contact Us ...

  1. Artificial Vision INTRODUCTION

    E-print Network

    Artificial Vision INTRODUCTION Dr. Christian Micheloni Department of Computer Science University of Udine, ITALY #12;2011 Prof. Micheloni Christian Università Degli Studi di Udine Artificial Vision The origins of vision · People of the ancient world have tried to understand the nature of the light

  2. VISION2015 ...................................................................1

    E-print Network

    Hung, Shih-Hao

    VISION2015 ------ ...................................................................1 ...............................................................................10 / #12; VISION 2015 -2- 1 2014 11 18 () 10:0011 25 () 23:59 11 18 ()10:00 11 19 ()10:00 103 2014 12 19 104 2015 1 9 https://info2.ntu.edu.tw/vision/ 2 () 2015 3 8 () 9

  3. Fruit over sunbed: carotenoid skin colouration is found more attractive than melanin colouration.

    PubMed

    Lefevre, Carmen E; Perrett, David I

    2015-02-01

    Skin colouration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid colouration and increased melanin colouration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear, firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid colouration, or (b) melanin colouration. We show, firstly, that both increased carotenoid colouration and increased melanin colouration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid colouration is consistently preferred over melanin colouration when levels of colouration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin colouration: men have darker skin than women and high melanization in male faces may further enhance this masculine trait, thus carotenoid colouration is not less desirable, but melanin colouration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice. PMID:25014019

  4. Cryptic differences in colour among Müllerian mimics: how can the visual capacities of predators and prey shape the evolution of wing colours?

    PubMed

    Llaurens, V; Joron, M; Théry, M

    2014-01-21

    Antagonistic interactions between predators and prey often lead to co-evolution. In the case of toxic prey, aposematic colours act as warning signals for predators and play a protective role. Evolutionary convergence in colour patterns among toxic prey evolves due to positive density-dependent selection and the benefits of mutual resemblance in spreading the mortality cost of educating predators over a larger prey assemblage. Comimetic species evolve highly similar colour patterns, but such convergence may interfere with intraspecific signalling and recognition in the prey community, especially for species involved in polymorphic mimicry. Using spectrophotometry measures, we investigated the variation in wing coloration among comimetic butterflies from distantly related lineages. We focused on seven morphs of the polymorphic species Heliconius numata and the seven corresponding comimetic species from the genus Melinaea. Significant differences in the yellow, orange and black patches of the wing were detected between genera. Perceptions of these cryptic differences by bird and butterfly observers were then estimated using models of animal vision based on physiological data. Our results showed that the most strikingly perceived differences were obtained for the contrast of yellow against a black background. The capacity to discriminate between comimetic genera based on this colour contrast was also evaluated to be higher for butterflies than for birds, suggesting that this variation in colour, likely undetectable to birds, might be used by butterflies for distinguishing mating partners without losing the benefits of mimicry. The evolution of wing colour in mimetic butterflies might thus be shaped by the opposite selective pressures exerted by predation and species recognition. PMID:24444083

  5. Local adaptation and divergence in colour signal conspicuousness between monomorphic and polymorphic lineages in a lizard.

    PubMed

    McLean, C A; Moussalli, A; Stuart-Fox, D

    2014-12-01

    Population differences in visual environment can lead to divergence in multiple components of animal coloration including signalling traits and colour patterns important for camouflage. Divergence may reflect selection imposed by different receivers (conspecifics, predators), which depends in turn on the location of the colour patch. We tested for local adaptation of two genetically and phenotypically divergent lineages of a rock-inhabiting lizard, Ctenophorus decresii, by comparing the visual contrast of colour patches to different receivers in native and non-native environments. The lineages differ most notably in male throat coloration, which is polymorphic in the northern lineage and monomorphic in the southern lineage, but also differ in dorsal and lateral coloration, which is visible to both conspecifics and potential predators. Using models of animal colour vision, we assessed whether lineage-specific throat, dorsal and lateral coloration enhanced conspicuousness to conspecifics, increased crypsis to birds or both, respectively, when viewed against the predominant backgrounds from each lineage. Throat colours were no more conspicuous against native than non-native rock but contrasted more strongly with native lichen, which occurs patchily on rocks inhabited by C. decresii. Conversely, neck coloration (lateral) more closely matched native lichen. Furthermore, although dorsal coloration of southern males was consistently more conspicuous to birds than that of northern males, both lineages had similar absolute conspicuousness against their native backgrounds. Combined, our results are consistent with local adaptation of multiple colour traits in relation to multiple receivers, suggesting that geographic variation in background colour has influenced the evolution of lineage-specific coloration in C. decresii. PMID:25330209

  6. Computational approaches to vision

    NASA Technical Reports Server (NTRS)

    Barrow, H. G.; Tenenbaum, J. M.

    1986-01-01

    Vision is examined in terms of a computational process, and the competence, structure, and control of computer vision systems are analyzed. Theoretical and experimental data on the formation of a computer vision system are discussed. Consideration is given to early vision, the recovery of intrinsic surface characteristics, higher levels of interpretation, and system integration and control. A computational visual processing model is proposed and its architecture and operation are described. Examples of state-of-the-art vision systems, which include some of the levels of representation and processing mechanisms, are presented.

  7. Microwave vision for robots

    NASA Technical Reports Server (NTRS)

    Lewandowski, Leon; Struckman, Keith

    1994-01-01

    Microwave Vision (MV), a concept originally developed in 1985, could play a significant role in the solution to robotic vision problems. Originally our Microwave Vision concept was based on a pattern matching approach employing computer based stored replica correlation processing. Artificial Neural Network (ANN) processor technology offers an attractive alternative to the correlation processing approach, namely the ability to learn and to adapt to changing environments. This paper describes the Microwave Vision concept, some initial ANN-MV experiments, and the design of an ANN-MV system that has led to a second patent disclosure in the robotic vision field.

  8. Visual impairment, visual functioning, and quality of life assessments in patients with glaucoma.

    PubMed Central

    Parrish, R K

    1996-01-01

    BACKGROUND/PURPOSE: To determine the relation between visual impairment, visual functioning, and the global quality of life in patients with glaucoma. METHODS: Visual impairment, defined with the American Medical Association Guides to the Evaluation of Permanent Impairment; visual functioning, measured with the VF-14 and the Field Test Version of the National Eye Institute-Visual Functioning Questionnaire (NEI-VFQ); and the global quality of life, assessed with the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), were determined in 147 consecutive patients with glaucoma. RESULTS: None of the SF-36 domains demonstrated more than a weak correlation with visual impairment. The VF-14 scores were moderately correlated with visual impairment. Of the twelve NEI-VFQ scales, distance activities and vision specific dependency were moderately correlated with visual impairment. Of the twelve NEI-VFQ scales, distance activities and vision specific dependency were moderately correlated with visual field impairment; vision specific social functioning, near activities, vision specific role difficulties, general vision, vision specific mental health, color vision, and driving were modestly correlated; visual pain was weakly correlated; and two were not significantly correlated. Correcting for visual actuity weakened the strength of the correlation coefficients. CONCLUSIONS: The SF-36 is unlikely to be useful in determining visual impairment in patients with glaucoma. Based on the moderate correlation between visual field impairment and the VF-14 score, this questionnaire may be generalizable to patients with glaucoma. Several of the NEI-VFQ scales correlate with visual field impairment scores in patients with a wide range of glaucomatous damage. PMID:8981717

  9. Impact of Low Vision on Well-Being in 10 European Countries

    Microsoft Academic Search

    S. M. Mojon-Azzi; A. Sousa-Poza; D. S. Mojon

    2008-01-01

    Background: Because of the growing life expectancy in developed countries and the exponential increase in vision loss with increasing age, a growing number of elderly persons will eventually suffer from visual impairment and blindness. This paper describes the association between self-reported vision and well-being in individuals aged 50 years and older and their families. Methods: Using binary logistic regressions on

  10. Navisio: Towards an integrated reading aid system for low vision patients

    E-print Network

    Paris-Sud XI, Université de

    diseases like macular degen- eration ( 50%), glaucoma, diabetic retinopathy and cataract. They cause/30 Normal Vision 20/30 to 20/70 Mild Visual Impairment 20/70 to 20/200 Moderate Low Vision 20/200 to 20

  11. Low vision goggles: optical design studies

    NASA Astrophysics Data System (ADS)

    Levy, Ofer; Apter, Boris; Efron, Uzi

    2006-08-01

    Low Vision (LV) due to Age Related Macular Degeneration (AMD), Glaucoma or Retinitis Pigmentosa (RP) is a growing problem, which will affect more than 15 million people in the U.S alone in 2010. Low Vision Aid Goggles (LVG) have been under development at Ben-Gurion University and the Holon Institute of Technology. The device is based on a unique Image Transceiver Device (ITD), combining both functions of imaging and Display in a single chip. Using the ITD-based goggles, specifically designed for the visually impaired, our aim is to develop a head-mounted device that will allow the capture of the ambient scenery, perform the necessary image enhancement and processing, and re-direct it to the healthy part of the patient's retina. This design methodology will allow the Goggles to be mobile, multi-task and environmental-adaptive. In this paper we present the optical design considerations of the Goggles, including a preliminary performance analysis. Common vision deficiencies of LV patients are usually divided into two main categories: peripheral vision loss (PVL) and central vision loss (CVL), each requiring different Goggles design. A set of design principles had been defined for each category. Four main optical designs are presented and compared according to the design principles. Each of the designs is presented in two main optical configurations: See-through system and Video imaging system. The use of a full-color ITD-Based Goggles is also discussed.

  12. Why colour in subterranean vertebrates? Exploring the evolution of colour patterns in caecilian amphibians

    Microsoft Academic Search

    K. C. WOLLENBERG; G. JOHN MEASEY

    2009-01-01

    aposematism; caecilians; colour; crypsis; evolution; Gymnophiona; independent contrasts; pattern; selection. Abstract The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so, their presence in subterranean taxa is perplexing. We evaluate the adaptive nature

  13. Vision and action

    NASA Astrophysics Data System (ADS)

    Fermueller, Cornelia; Aloimonos, Yiannis

    1994-06-01

    Our work on Active Vision has recently focused on the computational modelling of navigational tasks, where our investigations were guided by the idea of approaching vision for behavioral systems in form of modules that are directly related to perceptual tasks. These studies led us to branch in various directions and inquire into the problems that have to be addressed in order to obtain an overall understanding of perceptual systems. In this paper we present our views about the architecture of vision systems, about how to tackle the design and analysis of perceptual systems, and promising future research directions. Our suggested approach for understanding behavioral vision to realize the relationship of perception and action builds on two earlier approaches; the Medusa philosophy 3 and the Synthetic approach 15. The resulting framework calls for synthesizing an artificial vision system by studying vision competences of increasing complexity and at the same time pursuing the integration of the perceptual components with action and learning modules. We expect that Computer Vision research in the future will progress in tight collaboration with many other disciplines that are concerned with empirical approaches to vision, i.e. the understanding of biological vision. Throughout the paper we describe biological findings that motivate computational arguments which we believe will influence studies of Computer Vision in the near future.

  14. Group Vision Care Policy Vision Care for Life

    E-print Network

    New Mexico, University of

    Group Vision Care Policy Vision Care for Life EVIDENCE OF COVERAGE Provided by: VISION SERVICE PLAN ADMINISTRATOR: ADDRESS: Benefits are furnished under a vision care Policy purchased by the Group and provided by VISION SERVICE PLAN INSURANCE COMPANY(VSP) under which VSP is financially responsible for the payment

  15. BLUE VIEW VISION INSIGHT! Good news--your vision plan

    E-print Network

    Barrett, Jeffrey A.

    WELCOME TO BLUE VIEW VISION INSIGHT! Good news--your vision plan is flexible and easy to use, your discounts, and much more! Blue View Vision InsightSM University of California Student Health Insurance Plan (UC SHIP) 2012/13 Your Blue View Vision Insight Network Blue View Vision Insight offers you

  16. Brilliant Colours from a White Snow Cover

    ERIC Educational Resources Information Center

    Vollmer, Michael; Shaw, Joseph A

    2013-01-01

    Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

  17. Colour Mathematics: With Graphs and Numbers

    ERIC Educational Resources Information Center

    LoPresto, Michael C.

    2009-01-01

    The different combinations involved in additive and subtractive colour mixing can often be difficult for students to remember. Using transmission graphs for filters of the primary colours and a numerical scheme to write out the relationships are good exercises in analytical thinking that can help students recall the combinations rather than just…

  18. Colour polymorphism in birds: causes and functions

    Microsoft Academic Search

    P. Galeotti; D. Rubolini; P. O. Dunn; M. Fasola

    2003-01-01

    We studied polymorphism in all species of birds that are presently known to show intraspecific variation in plumage colour. At least three main mecha- nisms have been put forward to explain the maintenance of polymorphism: apostatic, disruptive and sexual selection. All of them make partly different predictions. Our aims were to investigate evolutionary causes and adaptive functions of colour polymorphism

  19. Skin colour and bilirubin in neonates

    Microsoft Academic Search

    A Knudsen; R Brodersen

    1989-01-01

    The correlation between the yellow colour of the skin and serum bilirubin concentration, reserve albumin concentration, and pH was investigated in 76 icteric neonates. Significant linear correlation existed between yellow colour of the skin and serum bilirubin concentration, reciprocal of the reserve albumin concentration, and the squared hydrogen ion concentration. Furthermore, the basic yellowness of the skin at birth correlated

  20. Mineralization in Rust-coloured Acarospora

    Microsoft Academic Search

    O. William Purvis; Anton Kearsley; Gordon Cressey; Anna T. Crewe; Mats Wedin

    2008-01-01

    The upper cortex and extracellular hyphal wall matrix are mineralized in both rust-coloured Acarospora sinopica and the paler A. smaragdula ‘f. subochracea’ in the form of microgranular or microbotryoidal phases. Analysis confirmed the distinctive colours are not simply due to hydrated iron oxides, as previously believed, and suggests mixed sulphide and oxide phases with little crystallinity, as well as other

  1. The Aurora Borealis and its Colours

    Microsoft Academic Search

    Warren de La Rue; Hugo Müller

    1880-01-01

    IN reference to Mr. Backhouse's letter last week (p. 145) we have nowhere stated that ``similarity in colour in electric discharges is sufficient to indicate similarity of constitution, eyen when their spectra are quite unlike'' If Mr. Backhouse will again read our paper on the Auroræ, he will see that we say that in the same gas the colour of

  2. Teaching Colour: From Canvas to Computer

    Microsoft Academic Search

    Rosa Maria; Melià Avià; Sant Adrià del Besòs. Spain; Octavi Plana Cobeta

    A solid basic knowledge on colour is important in various fields: art, physics, chemistry, biology, and technology. Even psychological aspects of colour perception should be considered when we approach this matter. This paper has the aim to help teachers to present science through an ITC approach that helps students to develop interest in science and to learn. We present a

  3. Rapidity gaps from colour string topologies

    Microsoft Academic Search

    G. Ingelman; A. Edin; R. Enberg; J. Rathsman; N. Timneanu

    1999-01-01

    Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and no-gap events, with a smooth transition and thereby a unified description of all final states.

  4. Rapidity Gaps from Colour String Topologies

    E-print Network

    G. Ingelman; A. Edin; R. Enberg; J. Rathsman; N. Timneanu

    1999-12-29

    Diffractive deep inelastic scattering at HERA and diffractive W and jet production at the Tevatron are well described by soft colour exchange models. Their essence is the variation of colour string-field topologies giving both gap and no-gap events, with a smooth transition and thereby a unified description of all final states.

  5. Three Dimensional Colour Pickers Yingxin Wu Masahiro Takatsuka

    E-print Network

    Hong,Seokhee

    and Munsell colour spaces. The colour palette is a slice cut off by a translucent plane from 3-D colour solids Council Copyright © 2005, Australian Computer Society, Inc. This paper appeared at the Asia Pacific

  6. Colour in insect thermoregulation: empirical and theoretical tests in the colour-changing grasshopper, Kosciuscola tristis.

    PubMed

    Umbers, K D L; Herberstein, M E; Madin, J S

    2013-01-01

    Body colours can result in different internal body temperatures, but evidence for the biological significance of colour-induced temperature differences is inconsistent. We investigated the relationship between body colour and temperature in a model insect species that rapidly changes colour. We used an empirical approach and constructed a heat budget model to quantify whether a colour change from black to turquoise has a role in thermoregulation for the chameleon grasshopper (Kosciuscola tristis). Our study shows that colour change in K. tristis provides relatively small temperature differences that vary greatly with wind speed (0.55 °C at ms(-1) to 0.05 °C at 10 ms(-1)). The biological significance of this difference is unclear and we discuss the requirement for more studies that directly test hypotheses regarding the fitness effects of colour in manipulating body temperature. PMID:23108152

  7. The Impact of Vision Loss on Personality Traits

    ERIC Educational Resources Information Center

    Papadopoulos, Konstantinos S.; Koustriava, Eleni; Charalampidou, Maria; Gerapostolou, Ioanna

    2013-01-01

    The aim of this study is to explore the differences in personality traits amongst adults with blindness, adults with low vision and sighted adults. Moreover, the relationship between the four scales of Eysenck's personality questionnaire and the demographic characteristics of participants with visual impairments was examined. There are no…

  8. Emotion-Induced Trade-Offs in Spatiotemporal Vision

    ERIC Educational Resources Information Center

    Bocanegra, Bruno R.; Zeelenberg, Rene

    2011-01-01

    It is generally assumed that emotion facilitates human vision in order to promote adaptive responses to a potential threat in the environment. Surprisingly, we recently found that emotion in some cases impairs the perception of elementary visual features (Bocanegra & Zeelenberg, 2009b). Here, we demonstrate that emotion improves fast temporal…

  9. Employment Retention after Vision Loss: Intensive Case Studies.

    ERIC Educational Resources Information Center

    Crudden, Adele; Fireison, Cara K.

    This study examined the lives of 10 individuals with blindness or severe visual impairment who maintained competitive employment despite their vision loss. The study was designed to provide information regarding the personal characteristics and current practices related to work environment alterations which enhance competitive employment…

  10. FPGA Vision Data Architecture

    NASA Technical Reports Server (NTRS)

    Morfopoulos, Arin C.; Pham, Thang D.

    2013-01-01

    JPL has produced a series of FPGA (field programmable gate array) vision algorithms that were written with custom interfaces to get data in and out of each vision module. Each module has unique requirements on the data interface, and further vision modules are continually being developed, each with their own custom interfaces. Each memory module had also been designed for direct access to memory or to another memory module.

  11. Embedded Vision Challenges

    Microsoft Academic Search

    Oliver Sidla; Norbert Brändle; Wanda Benesova; Marcin Rosner; Yuriy Lypetskyy

    The processing power of modern smart cameras allows more than just simple pixel manipulations for machine vision and inspection\\u000a tasks. Smart cameras can run complex vision algorithms and thus gradually move the processing and analysis of video streams\\u000a from large centralized servers to processing ‘on the edge’. This chapter deals with the challenges of bringing high-level\\u000a vision software from PCs

  12. Artificial human vision camera

    NASA Astrophysics Data System (ADS)

    Goudou, J.-F.; Maggio, S.; Fagno, M.

    2014-10-01

    In this paper we present a real-time vision system modeling the human vision system. Our purpose is to inspire from human vision bio-mechanics to improve robotic capabilities for tasks such as objects detection and tracking. This work describes first the bio-mechanical discrepancies between human vision and classic cameras and the retinal processing stage that takes place in the eye, before the optic nerve. The second part describes our implementation of these principles on a 3-camera optical, mechanical and software model of the human eyes and associated bio-inspired attention model.

  13. Piaget's Water-Level Task: The Impact of Vision on Performance

    ERIC Educational Resources Information Center

    Papadopoulos, Konstantinos; Koustriava, Eleni

    2011-01-01

    In the present study, the aim was to examine the differences in performance between children and adolescents with visual impairment and sighted peers in the water-level task. Twenty-eight individuals with visual impairments, 14 individuals with blindness and 14 individuals with low vision, and 28 sighted individuals participated in the present…

  14. Artificial selection for food colour preferences.

    PubMed

    Cole, Gemma L; Endler, John A

    2015-04-01

    Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection. PMID:25740894

  15. Physicochemical and physiological basis of dichromatic colour

    NASA Astrophysics Data System (ADS)

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

  16. Physicochemical and physiological basis of dichromatic colour.

    PubMed

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum. PMID:17534588

  17. Near Vision Test for Adults

    MedlinePLUS

    Near vision test for adults This test will check your close-up vision in each eye. Before you take this test, ... This test requires you to print the Near Vision Chart. The appearance of your printed chart may ...

  18. Colouration and Colour Changes of the Fiddler Crab, Uca capricornis: A Descriptive Study

    PubMed Central

    Detto, Tanya; Hemmi, Jan M.; Backwell, Patricia R. Y.

    2008-01-01

    Colour changes in animals may be triggered by a variety of social and environmental factors and may occur over a matter of seconds or months. Crustaceans, like fiddler crabs (genus Uca), are particularly adept at changing their colour and have been the focus of numerous studies. However, few of these studies have attempted to quantitatively describe the individual variation in colour and pattern or their adaptive significance. This paper quantitatively describes the colour patterns of the fiddler crab Uca capricornis and their ability to change on a socially significant timescale. The most dramatic changes in colour pattern are associated with moulting. These ontogenetic changes result in a general reduction of the colour pattern with increasing size, although females are more colourful and variable than similarly-sized males. Uca capricornis are also capable of rapid colour changes in response to stress, but show no endogenous rhythms associated with the semilunar and tidal cycles commonly reported in other fiddler crabs. The extreme colour polymorphism and the relative stability of the colour patterns in Uca capricornis are consistent with their use in visually mediated mate recognition. PMID:18286186

  19. The colour wheels of art, perception, science and physiology

    NASA Astrophysics Data System (ADS)

    Harkness, Nick

    2006-06-01

    Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

  20. Vision in the Superintendency.

    ERIC Educational Resources Information Center

    Johnson, Susan Moore

    1993-01-01

    Summarizes the visions of 12 newly appointed superintendents from 4 northeastern states. In composing their visions, single-handedly from the start or collaborative over time, superintendents must cope with complex realities and competing demands. Although expected to emulate visionary corporate leaders, superintendents must envision within a…

  1. Overview of computer vision

    SciTech Connect

    Gevarter, W.B.

    1982-09-01

    An overview of computer vision is provided. Image understanding and scene analysis are emphasized, and pertinent aspects of pattern recognition are treated. The basic approach to computer vision systems, the techniques utilized, applications, the current existing systems and state-of-the-art issues and research requirements, who is doing it and who is funding it, and future trends and expectations are reviewed.

  2. New Term, New Vision?

    ERIC Educational Resources Information Center

    Ravenhall, Mark

    2011-01-01

    During the affluent noughties it was sometimes said of government that it had "more visions than Mystic Meg and more pilots than British Airways". In 2011, the pilots, the pathfinders, the new initiatives are largely gone--implementation is the name of the game--but the visions remain. The latest one, as it affects adult learners, is in the…

  3. Vision Texture for Annotation

    Microsoft Academic Search

    Rosalind W. Picard; Thomas P. Minka

    1995-01-01

    This paper demonstrates a new application ofcomputer vision to digital libraries -- the use oftexture for annotation, the description of content.Vision-based annotation assists the userin attaching descriptions to large sets of imagesand video. If a user labels a piece of an imageas "water," a texture model can be used topropagate this label to other "visually similar"regions. However, a serious problem

  4. Vision assessment using the NIH Toolbox

    PubMed Central

    McKean-Cowdin, Roberta; Vitale, Susan; Slotkin, Jerry; Hays, Ron D.

    2013-01-01

    Vision is a sensation that is created from complex processes and provides us with a representation of the world around us. There are many important aspects of vision, but visual acuity was judged to be the most appropriate vision assessment for the NIH Toolbox for Assessment of Neurological and Behavioral Function, both because of its central role in visual health and because acuity testing is common and relatively inexpensive to implement broadly. The impact of visual impairments on health-related quality of life also was viewed as important to assess, in order to gain a broad view of one's visual function. To test visual acuity, an easy-to-use software program was developed, based on the protocol used by the E-ETDRS. Children younger than 7 years were administered a version with only the letters H, O, T, and V. Reliability and validity of the Toolbox visual acuity test were very good. A 53-item vision-targeted, health-related quality of life survey was also developed. PMID:23479542

  5. Panoramic stereo sphere vision

    NASA Astrophysics Data System (ADS)

    Feng, Weijia; Zhang, Baofeng; Röning, Juha; Zong, Xiaoning; Yi, Tian

    2013-01-01

    Conventional stereo vision systems have a small field of view (FOV) which limits their usefulness for certain applications. While panorama vision is able to "see" in all directions of the observation space, scene depth information is missed because of the mapping from 3D reference coordinates to 2D panoramic image. In this paper, we present an innovative vision system which builds by a special combined fish-eye lenses module, and is capable of producing 3D coordinate information from the whole global observation space and acquiring no blind area 360°×360° panoramic image simultaneously just using single vision equipment with one time static shooting. It is called Panoramic Stereo Sphere Vision (PSSV). We proposed the geometric model, mathematic model and parameters calibration method in this paper. Specifically, video surveillance, robotic autonomous navigation, virtual reality, driving assistance, multiple maneuvering target tracking, automatic mapping of environments and attitude estimation are some of the applications which will benefit from PSSV.

  6. Optimisation of colour schemes to accurately display mass spectrometry imaging data based on human colour perception.

    PubMed

    Race, Alan M; Bunch, Josephine

    2015-03-01

    The choice of colour scheme used to present data can have a dramatic effect on the perceived structure present within the data. This is of particular significance in mass spectrometry imaging (MSI), where ion images that provide 2D distributions of a wide range of analytes are used to draw conclusions about the observed system. Commonly employed colour schemes are generally suboptimal for providing an accurate representation of the maximum amount of data. Rainbow-based colour schemes are extremely popular within the community, but they introduce well-documented artefacts which can be actively misleading in the interpretation of the data. In this article, we consider the suitability of colour schemes and composite image formation found in MSI literature in the context of human colour perception. We also discuss recommendations of rules for colour scheme selection for ion composites and multivariate analysis techniques such as principal component analysis (PCA). PMID:25649999

  7. Why colour in subterranean vertebrates? Exploring the evolution of colour patterns in caecilian amphibians.

    PubMed

    Wollenberg, K C; Measey, C John

    2009-05-01

    The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so,their presence in subterranean taxa is perplexing. We evaluate the adaptive nature of colour patterns in nearly a third of all known species of caecilians, an order of amphibians most of which live in tropical soils and leaf litter. We found that certain colour pattern elements in caecilians can be explained based on characteristics concerning above-ground movement. Our study implies that certain caecilian colour patterns have convergently evolved under selection and we hypothesize their function most likely to be a synergy of aposematism and crypsis, related to periods when individuals move overground. In a wider context, our results suggest that very little exposure to daylight is required to evolve and maintain a varied array of colour patterns in animal skin. PMID:21462404

  8. Effectiveness of low vision services in improving patient quality of life at Aravind Eye Hospital

    PubMed Central

    Do, Anna T; Ilango, Krishanmurthy; Ramasamy, Dhivya; Kalidasan, Suriya; Balakrishnan, Vijayakumar; Chang, Robert T

    2014-01-01

    Context: In India, where the heavy burden of visual impairment exists, low vision services are scarce and under-utilized. Aims: Our study was designed to survey the effectiveness of low vision exams and visual aids in improving patient quality of life in southern rural India. Subjects and Methods: The low vision quality of life (LVQOL) questionnaire measures vision-related quality of life through 25 questions on a Likert scale of 0–5 that pertain to (1) mobility, distance vision, and lighting; (2) psychological adjustment; (3) reading and fine work; and (4) activities of daily living. This tool was translated into Tamil and verbally administered to 55 new low vision referral patients before their first visit at the low vision clinic at Aravind Eye Hospital. Low vision aids (LVAs) were prescribed at the discretion of the low vision specialist. 1-month later, the same questionnaire was administered over the phone. Results: About 44 of 55 low vision patients completed baseline and follow-up LVQOL surveys, and 30 normal vision controls matched for age, gender, and education were also surveyed (average 117.34 points). After the low vision clinic visit, the low vision group demonstrated a 4.55-point improvement in quality of life (from 77.77 to 82.33 points, P = 0.001). Adjusting for age, gender, and education, the low vision patients who also received LVAs (n = 24) experienced an even larger increase than those who did not (n = 20) (8.89 points, P < 0.001). Conclusion: Low vision services and visual aids can improve the quality of life in South Indian rural population regardless of age, gender, and education level. Thus, all low vision patients who meet the criteria should be referred for evaluation. PMID:25579355

  9. An Investigation of First-Order False Belief Understanding of Children with Congenital Profound Visual Impairment

    ERIC Educational Resources Information Center

    Green, Sarah; Pring, Linda; Swettenham, John

    2004-01-01

    This study assessed theory of mind understanding in children with congenital profound visual impairment (CPVI): children who have had no access to visual information throughout development. Participants were 18 children with CPVI and no other impairments, aged between 5 and 11 years, and 18 children with normal vision, matched individually on…

  10. Consumers' Perspectives on Effective Orientation and Mobility Services for Diabetic Adults Who Are Visually Impaired

    ERIC Educational Resources Information Center

    Griffin-Shirley, Nora; Kelley, Pat; Matlock, Dwayne; Page, Anita

    2006-01-01

    The authors interviewed and videotaped diabetic adults with visual impairments about their perceptions of orientation and mobility (O&M) services that they had received. The visual impairments of these middle-aged adults ranged from totally blind to low vision. The interview questions focused on demographic information about the interviewees, the…

  11. Teacher Variations when Administering Math Graphics Items to Students with Visual Impairments

    ERIC Educational Resources Information Center

    Schoch, Christina Sigrid

    2010-01-01

    This exploratory study investigated the techniques used by teachers of the visually impaired when administering math questions with graphics to students with blindness or low vision. The researcher observed and videotaped 10 pairs of students with visual impairments and their teachers while the students were taking a test that consisted of 12…

  12. Stereotyped Movements among Children Who Are Visually Impaired

    ERIC Educational Resources Information Center

    Gal, Eynat; Dyck, Murray J.

    2009-01-01

    Does the severity of visual impairment affect the prevalence and severity of stereotyped movements? In this study, children who were blind or had low vision, half of whom had intellectual disabilities, were assessed. The results revealed that blindness and global delays were associated with more sensory processing dysfunction and more stereotyped…

  13. An Experimental Investigation into Wayfinding Directions for Visually Impaired People

    E-print Network

    Dunlop, Mark D.

    and systems for visually impaired people. These technological advancements, however, have not been matched of congenitally blind people (e.g. how is environmental information learnt, processed, and used when attempting interfaces are slow to use and more demanding on memory than vision or touch, and Strothotte et al [4

  14. Federal regulation of vision enhancement devices for normal and abnormal vision

    NASA Astrophysics Data System (ADS)

    Drum, Bruce

    2006-09-01

    The Food and Drug Administration (FDA) evaluates the safety and effectiveness of medical devices and biological products as well as food and drugs. The FDA defines a device as a product that is intended, by physical means, to diagnose, treat, or prevent disease, or to affect the structure or function of the body. All vision enhancement devices fulfill this definition because they are intended to affect a function (vision) of the body. In practice, however, FDA historically has drawn a distinction between devices that are intended to enhance low vision as opposed to normal vision. Most low vision aids are therapeutic devices intended to compensate for visual impairment, and are actively regulated according to their level of risk to the patient. The risk level is usually low (e.g. Class I, exempt from 510(k) submission requirements for magnifiers that do not touch the eye), but can be as high as Class III (requiring a clinical trial and Premarket Approval (PMA) application) for certain implanted and prosthetic devices (e.g. intraocular telescopes and prosthetic retinal implants). In contrast, the FDA usually does not actively enforce its regulations for devices that are intended to enhance normal vision, are low risk, and do not have a medical intended use. However, if an implanted or prosthetic device were developed for enhancing normal vision, the FDA would likely decide to regulate it actively, because its intended use would entail a substantial medical risk to the user. Companies developing such devices should contact the FDA at an early stage to clarify their regulatory status.

  15. "Object vision" and "spatial vision": the neuropsychological evidence for the distinction.

    PubMed

    Ettlinger, G

    1990-09-01

    The distinction between "object vision" and "spatial vision" was made by Ungerleider and Mishkin (1982) on the evidence of behavioural and neuroanatomical studies, largely with monkeys. It holds that separate cortical systems are involved, the occipito-temporal in object vision, the occipito-parietal in spatial vision. This distinction has been unquestioned; it appears as though fact in influential textbooks; but has never been subjected to critical scrutiny. Theoretically, there are substantial difficulties, for instance because during perception objects do not form a special category, apart from their features; and because shape, pattern and size are spatial features of objects. Empirically, for the monkey the behavioural distinction does not hold (because parietal cortex is not the sole cortical area involved in "spatial vision"); and in man because parietal lesions have long been known to lead to impaired perception of incomplete pictures. Moreover, although Ungerleider and Mishkin do not generalise their distinction to touch, this sense deserves consideration, given that Mishkin had earlier argued that vision and touch have a similar organisation. In touch there are direct anatomical connections between the areas serving "object touch" and "spatial touch", and both in man and in the monkey it seems established that the same region processes spatial performance in vision and in touch. Further work is needed particularly on the spatial disorder after parietal lesions: in the monkey, research has frequently been confined to one non-specific test; in man, important differences related to the laterality of the lesion, have only recently emerged. Then "spatial performance" may be found to be more closely linked to motor output than to sensory input. PMID:2123426

  16. David R. Hilbert Colour, Theories of

    E-print Network

    Hilber, David

    views as Democritus and Galileo. Although the metaphysics is no longer atomistic in a strict sense, many be a property of external objects as were Democritus and Galileo. Colours as perceived are commonly seen

  17. Salience of Primary and Secondary Colours in Infancy

    ERIC Educational Resources Information Center

    Franklin, Anna; Pitchford, Nicola; Hart, Lynsey; Davies, Ian R. L.; Clausse, Samantha; Jennings, Siobhan

    2008-01-01

    Primary colour terms ("black", "white", "red", "green", "yellow", and "blue") are more fundamental in colour language than secondary colour terms ("pink", "purple", "orange", "brown", and "grey"). Here, we assess whether this distinction exists in the absence of language, by investigating whether primary colours attract and sustain preverbal…

  18. Inheritance of seed colour in turnip rape ( Brassica campestris L.)

    Microsoft Academic Search

    A. Schwetka

    1982-01-01

    The inheritance of seed colour was investigated in the progenies of crosses between seven yellow seeded forms and a brown seeded one of turnip rape (Brassica campestris L.). Seed colour differences were found to be determined in each case by one or two genes with epistatic effect. Moreover, independent inheritance of hilum colour was observed. Seed colour was predominantly but

  19. Fano colourings of cubic graphs and the Fulkerson Conjecture

    Microsoft Academic Search

    Edita Mácajová; Martin Skoviera

    2005-01-01

    A Fano colouring is a colouring of the edges of a cubic graph by points of the Fano plane such that the colours of any three mutually adjacent edges form a line of the Fano plane. It has recently been shown by Holroyd and Skoviera (J. Combin. Theory Ser. B, to appear) that a cubic graph has a Fano colouring

  20. INTRODUCTION Animal colouration depends on an interplay of selective forces.

    E-print Network

    Carleton, Karen L.

    sensitivity, the spectral properties of the fish and its background, and the light which illuminates them­male competition, may have driven evolution of male nuptial colouration in these fish. In cichlids, male colour brightly coloured than the females of most Lake Malawi species. However, several factors affect how colour

  1. Rapidity Gaps in DIS through Soft Colour Interactions

    Microsoft Academic Search

    A. Edin; G. Ingelman; J. Rathsman

    1995-01-01

    We present a new mechanism for the creation of large rapidity gaps in DIS events at HERA. Soft colour interactions between perturbatively produced partons and colour-charges in the proton remnant, modifies the colour structure for hadronization giving colour singlet systems that are well separated in rapidity. An explicit model is presented that, although the detailed results depend on the initial

  2. Angle-Insensitive Structural Colours based on Metallic Nanocavities and Coloured Pixels beyond the Diffraction Limit

    PubMed Central

    Wu, Yi-Kuei Ryan; Hollowell, Andrew E.; Zhang, Cheng; Guo, L. Jay

    2013-01-01

    To move beyond colorant-based pigmentation display technologies, a variety of photonic and plasmonic crystal based structures have been designed and applied as colour filters. Nanostructure based colour filtering offers increased efficiencies, low power consumption, slim dimensions, and enhanced resolution. However, incident angle tolerance still needs to be improved. In this work, we propose a new scheme through localized resonance in metallic nanoslits by light funneling. Angle insensitive colour filters up to ±80 degrees have been achieved, capable of wide colour tunability across the entire visible band with pixel size beyond the diffraction limit (~?/2). This work opens the door to angle insensitive manipulation of light with structural filtering. PMID:23378925

  3. Colour Reagent for Paper Chromatography of Steroids

    Microsoft Academic Search

    A. Bodánszky; J. Kollonitsch

    1955-01-01

    FOR the paper chromatography of steroids several colour reagents are used, such as 2,4-dinitrophenyl-hydrazine, Zimmermann's reagent, phosphomolybdic acid, antimony trichloride, etc. Their common defect is that the reagent gives some colour with the paper itself, and so the contrast between spot and paper is too small. We have found that acid aniline phthalate in alcoholic solution-the reagent Partridge used for

  4. Caramel colours--a historical introduction.

    PubMed

    Chappel, C I; Howell, J C

    1992-05-01

    Caramel colours used in the manufacture of a wide variety of foods and beverages have been an item of commerce for more than one hundred years. The regulatory history of these additives in the US, the UK, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the EC is reviewed, and an introduction to the safety studies of caramel colours in this issue of Food and Chemical Toxicology is provided. PMID:1644375

  5. Performance evaluation of local colour invariants

    Microsoft Academic Search

    Gertjan J. Burghouts; Jan-mark Geusebroek

    2009-01-01

    In this paper, we compare local colour descriptors to grey-value descriptors. We adopt the evaluation framework of Mikolayzcyk and Schmid. We modify the framework in several ways. We decompose the evaluation framework to the level of local grey-value invariants on which common region descriptors are based. We compare the discriminative power and invariance of grey-value invariants to that of colour

  6. Vision 2020 |LSU Residential Colleges Program Vision 2020

    E-print Network

    Harms, Kyle E.

    Vision 2020 |LSU Residential Colleges Program Vision 2020 Residential Colleges Program Department #12;Vision 2020 | LSU Residential Colleges Program 11.24.2011 Page | - 2 - Mission Statement MISSION that promote academic success and personal development in support of Flagship 2020. VISION Be a nationally

  7. Seasonal colour and antipredator behaviour in Etheostoma (Percidae).

    PubMed

    Moran, R L; von Ende, C N; King, B H

    2014-04-01

    This study examined how colour varies across season and sex in the fantail darter Etheostoma flabellare and the banded darter Etheostoma zonale. Etheostoma flabellare has male-only parental care and exhibited slight sexual dimorphism in overall colour, with no discernible effect of season on colour; whereas E. zonale does not have parental care and exhibited substantial sexual dimorphism in colour, but only in the breeding season. Additionally, antipredator behaviour of E. zonale was compared between males that were fully coloured during the breeding season and males that were partially coloured at that time, but the effects of colour and season were not consistent across males. PMID:24588710

  8. Computer Vision The goal of computer vision

    E-print Network

    Kosecka, Jana

    : Fei-Fei, Fergus & Torralba Object categorization sky building flag wall banner bus cars bus face Surveillance and security Movies, news, sports Medical and scientific images Vision is useful: Images. Seitz #12;4/30/10 18 Optical character recognition (OCR) Digit recognition, AT&T labs Technology

  9. Flower colour adaptation in a mimetic orchid

    PubMed Central

    Newman, Ethan; Anderson, Bruce; Johnson, Steven D.

    2012-01-01

    Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowers in the western part of its range and orange flowers in the eastern part—a colour shift that we hypothesized to be the outcome of selection for resemblance to different local nectar-producing plants. Using reciprocal translocations of red and orange phenotypes as well as arrays of artificial flowers, we found that the butterfly Aeropetes tulbaghia, the only pollinator of the orchid, preferred both the red phenotype and red artificial flowers in the west where its main nectar plant also has red flowers, and both the orange phenotype and orange artificial flowers in the east, where its main nectar plant has orange flowers. This phenotype by environment interaction demonstrates that the flower colour shift in D. ferruginea is adaptive and driven by local colour preference in its pollinator. PMID:22298842

  10. Colourful parrot feathers resist bacterial degradation

    PubMed Central

    Burtt, Edward H.; Schroeder, Max R.; Smith, Lauren A.; Sroka, Jenna E.; McGraw, Kevin J.

    2011-01-01

    The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage. PMID:20926430

  11. The Computer Vision Handbook

    NSDL National Science Digital Library

    A work in progress, this site outlines resources for computer vision techniques, including societies and funding; general references and lab procedures; and indices and programs for mathematics, computer science, graphics and physics. The goal of this electronic handbook is to provide graduate students and others new to computer vision research with a useful tool because, "...the computer vision literature is vast and diverse. Furthermore, computer vision research depends on techniques from a wide range of other fields. Therefore, it is difficult for newcomers (e.g. graduate students) to assimilate enough background material to do their research," says the site's collaborative authors, scientists from the University of Wisconsin-Eau Claire, Harvey Mudd College, and the University of Iowa. This metasite is well-organized into subheadings: The Computer Vision Community, Computer Vision, Mathematics, Computer Science, Hardware, and Allied Fields, and a glossary is also available. Because it collects so much of the literature and so many Websites, the Computer Vision Handbook is an indispensable tool for graduate students and faculty in the field.

  12. A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light

    ERIC Educational Resources Information Center

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

    2009-01-01

    To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

  13. Virtual vision loss simulator.

    PubMed

    Toufaili, Feras M; Seibel, Eric J; McIntyre, David J

    2004-01-01

    Vision loss is common among people over the age of 65 and the condition is irreversible in most cases. Our simulator is a means to effectively and accurately inform people about the nature of common vision problems, initially limited to medically accurate simulations of cataract and macular degeneration. Using an eye tracker that continuously determines the subject's fixation point, a systematically degraded digital image displayed on an HMD can be a powerful educational tool. This article presents our Virtual Vision Loss (VVL) simulator and the developed simulation techniques based on calibration from 27 subjects. PMID:15544311

  14. Stereo vision and strabismus.

    PubMed

    Read, J C A

    2015-02-01

    Binocular stereopsis, or stereo vision, is the ability to derive information about how far away objects are, based solely on the relative positions of the object in the two eyes. It depends on both sensory and motor abilities. In this review, I briefly outline some of the neuronal mechanisms supporting stereo vision, and discuss how these are disrupted in strabismus. I explain, in some detail, current methods of assessing stereo vision and their pros and cons. Finally, I review the evidence supporting the clinical importance of such measurements. PMID:25475234

  15. Identifying solutions to medication adherence in the visually impaired elderly.

    PubMed

    Smith, Miranda; Bailey, Trista

    2014-02-01

    Adults older than 65 years of age with vision impairment are more likely to have difficulty managing medications compared with people having normal vision. This patient population has difficulty reading medication information and may take the wrong medication or incorrect doses of medication, resulting in serious consequences, including overdose or inadequate treatment of health problems. Visually impaired patients report increased anxiety related to medication management and must rely on others to obtain necessary drug information. Pharmacists have a unique opportunity to pursue accurate medication adherence in this special population. This article reviews literature illustrating how severe medication mismanagement can occur in the visually impaired elderly and presents resources and solutions for pharmacists to take a larger role in adherence management in this population. PMID:24513423

  16. Wavefront Aberrations and Peripheral Vision

    E-print Network

    Wavefront Aberrations and Peripheral Vision LINDA LUNDSTRÖM Doctoral Thesis Department of Applied with large central visual field loss to better utilize their remaining vision. Central visual field loss means that the person has to rely on peripheral vision since the direct vision is lost, often due

  17. BINOCULAR VISION Rahul Bhola, MD

    E-print Network

    Casavant, Tom

    BINOCULAR VISION Rahul Bhola, MD Pediatric Ophthalmology Fellow The University of Iowa Department of Ophthalmology & Visual Sciences posted Jan. 18, 2006, updated Jan. 23, 2006 Binocular vision is one. Binocular Single Vision may be defined as the state of simultaneous vision, which is achieved

  18. Computational Architectures for Responsive Vision

    E-print Network

    Little, Jim

    Computational Architectures for Responsive Vision: the Vision Engine James J. Little, Rod Barman, Stewart Kingdon and Jiping Lu Technical Report 91­25 November 1991 Laboratory for Computational Vision email: little@cs.ubc.ca Abstract To respond actively to a dynamic environment, a vision system must

  19. A Three-Phase Qualitative Study of Dual-Certified Vision Education Professionals in the Southwestern United States

    ERIC Educational Resources Information Center

    Griffin-Shirley, Nora; Pogrund, Rona L.; Smith, Derrick W.; Duemer, Lee

    2009-01-01

    The purpose of this qualitative study was to develop a comprehensive understanding of the roles and responsibilities of vision education professionals who are dual-certified as teachers of students with visual impairments and orientation and mobility specialists. Through three phases, the study combined interviews and observations of the vision…

  20. Using Computer Vision to Access Appliance Displays

    PubMed Central

    Fusco, Giovanni; Tekin, Ender; Ladner, Richard E.; Coughlan, James M.

    2014-01-01

    People who are blind or visually impaired face difficulties accessing a growing array of everyday appliances, needed to perform a variety of daily activities, because they are equipped with electronic displays. We are developing a “Display Reader” smartphone app, which uses computer vision to help a user acquire a usable image of a display, to address this problem. The current prototype analyzes video from the smartphone’s camera, providing real-time feedback to guide the user until a satisfactory image is acquired, based on automatic estimates of image blur and glare. Formative studies were conducted with several blind and visually impaired participants, whose feedback is guiding the development of the user interface. The prototype software has been released as a Free and Open Source (FOSS) project. PMID:25531011

  1. Memory Impairment in Children with Language Impairment

    ERIC Educational Resources Information Center

    Baird, Gillian; Dworzynski, Katharina; Slonims, Vicky; Simonoff, Emily

    2010-01-01

    Aim: The aim of this study was to assess whether any memory impairment co-occurring with language impairment is global, affecting both verbal and visual domains, or domain specific. Method: Visual and verbal memory, learning, and processing speed were assessed in children aged 6 years to 16 years 11 months (mean 9y 9m, SD 2y 6mo) with current,…

  2. Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

    PubMed Central

    Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Özcan, Mutlu; Lassila, Lippo

    2013-01-01

    This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core–veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm?min?1). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)?(39.7±4.7) and (27.4±5.6)?(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia–veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal–ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core–veneer adhesion. Metal–ceramic adhesion was more reliable than all zirconia–veneer ceramics tested. PMID:24158142

  3. Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients.

    PubMed

    Aktas, Guliz; Sahin, Erdal; Vallittu, Pekka; Ozcan, Mutlu; Lassila, Lippo

    2013-12-01

    This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients (TECs), when zirconia ceramics were coloured at green stage. Zirconia blocks (N=240; 6 mm×7 mm×7 mm) were manufactured from two materials namely, ICE Zirconia (Group 1) and Prettau Zirconia (Group 2). In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid (shade A2). Three different veneering ceramics with different TEC (ICE Ceramic, GC Initial Zr and IPS e.max Ceram) were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys (Esteticor Plus) veneered with ceramic (VM 13) (n=16) acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine (0.5 mm?min(-1)). Neither the zirconia core material (P=0.318) nor colouring (P=0.188) significantly affected the results (three-way analysis of variance, Tukey's test). But the results were significantly affected by the veneering ceramic (P=0.000). Control group exhibited significantly higher mean bond strength values (45.7±8) MPa than all other tested groups ((27.1±4.1)-(39.7±4.7) and (27.4±5.6)-(35.9±4.7) MPa with and without colouring, respectively) (P<0.001). While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering <1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered >1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested. PMID:24158142

  4. Capturing Natural-Colour 3D Models of Insects for Species Discovery and Diagnostics

    PubMed Central

    Nguyen, Chuong V.; Lovell, David R.; Adcock, Matt; La Salle, John

    2014-01-01

    Collections of biological specimens are fundamental to scientific understanding and characterization of natural diversity—past, present and future. This paper presents a system for liberating useful information from physical collections by bringing specimens into the digital domain so they can be more readily shared, analyzed, annotated and compared. It focuses on insects and is strongly motivated by the desire to accelerate and augment current practices in insect taxonomy which predominantly use text, 2D diagrams and images to describe and characterize species. While these traditional kinds of descriptions are informative and useful, they cannot cover insect specimens “from all angles” and precious specimens are still exchanged between researchers and collections for this reason. Furthermore, insects can be complex in structure and pose many challenges to computer vision systems. We present a new prototype for a practical, cost-effective system of off-the-shelf components to acquire natural-colour 3D models of insects from around 3 mm to 30 mm in length. (“Natural-colour” is used to contrast with “false-colour”, i.e., colour generated from, or applied to, gray-scale data post-acquisition.) Colour images are captured from different angles and focal depths using a digital single lens reflex (DSLR) camera rig and two-axis turntable. These 2D images are processed into 3D reconstructions using software based on a visual hull algorithm. The resulting models are compact (around 10 megabytes), afford excellent optical resolution, and can be readily embedded into documents and web pages, as well as viewed on mobile devices. The system is portable, safe, relatively affordable, and complements the sort of volumetric data that can be acquired by computed tomography. This system provides a new way to augment the description and documentation of insect species holotypes, reducing the need to handle or ship specimens. It opens up new opportunities to collect data for research, education, art, entertainment, biodiversity assessment and biosecurity control. PMID:24759838

  5. Why simulations of colour for CVD observers might not be what they seem

    NASA Astrophysics Data System (ADS)

    Green, Phil

    2015-01-01

    A common task in universal design is to create a 'simulation' of the appearance of a colour image as it appears to a CVD observer. Although such simulations are useful in illustrating the particular problems that a CVD observer has in discriminating between colours in an image, it may not be reasonable to assume that such a simulation accurately conveys the experience of the CVD observer to an observer with normal vision. Two problems with this assumption are discussed here. First, it risks confusing appearance with sensation. A colour appearance model can more or less accurately predict the change in appearance of a colour when it is viewed under different conditions, but does not define the actual sensation. Such a sensation cannot be directly communicated but merely located on a scale with other related sensations. In practice we avoid this epistemological problem by asking observers to judge colour matches, relations and differences, none of which requires examination of the sensation itself. Since we do not truly know what sensation a normal observer experiences, it seems unscientific to suppose that we can do so for CVD observers. Secondly, and following from the above, the relation between stimulus and corresponding sensation is established as part of neural development during infancy, and while we can determine the stimulus we cannot readily determine what sensation the stimulus is mapped to, or what the available range of sensations is for a given observer. It is suggested that a similar range of sensations could be available to CVD observers as to normal observers.

  6. Structural colour and iridescence in plants: the poorly studied relations of pigment colour

    PubMed Central

    Glover, Beverley J.; Whitney, Heather M.

    2010-01-01

    Background Colour is a consequence of the optical properties of an object and the visual system of the animal perceiving it. Colour is produced through chemical and structural means, but structural colour has been relatively poorly studied in plants. Scope This Botanical Briefing describes the mechanisms by which structures can produce colour. In plants, as in animals, the most common mechanisms are multilayers and diffraction gratings. The functions of structural colour are then discussed. In animals, these colours act primarily as signals between members of the same species, although they can also play roles in camouflaging animals from their predators. In plants, multilayers are found predominantly in shade-plant leaves, suggesting a role either in photoprotection or in optimizing capture of photosynthetically active light. Diffraction gratings may be a surprisingly common feature of petals, and recent work has shown that they can be used by bees as cues to identify rewarding flowers. Conclusions Structural colour may be surprisingly frequent in the plant kingdom, playing important roles alongside pigment colour. Much remains to be discovered about its distribution, development and function. PMID:20142263

  7. Vision Loss, Sudden

    MedlinePLUS

    ... or CT Ultrasonography of the carotid arteries ECG Continuous monitoring of heart rhythm Blockage of the central ... or CT ECG Ultrasonography of the carotid arteries Continuous monitoring of heart rhythm Sudden loss of vision ...

  8. The Computer Vision Homepage

    NSDL National Science Digital Library

    The Computer Vision Homepage, established at Carnegie Mellon University in 1994, serves as a central location for links to websites relating to computer vision research. The resources are divided into specific subpages, including Vision Groups, Hardware, Software, Demos, Test Images, Conferences, Publications, and General Info. A separate subpage also lists links to websites on related topics, such as Geographic Information Systems and Pattern Recognition. Recent additions to the website are listed in chronological order in the New Additions section. The Computer Vision Homepage is currently maintained by Daniel Huber on a volunteer basis and he invites others to contribute suggestions for websites to add to the list or to assist in updating the Homepage.

  9. Your Child's Vision

    MedlinePLUS

    ... Other eye conditions need immediate attention, such as retinopathy of prematurity (a disease that affects the eyes of premature ... Vision Problems Affect Schoolwork? Strabismus Surgeries and Procedures: Retinopathy of Prematurity First Aid: Eye Injuries Eye Injuries Retinoblastoma Retinopathy ...

  10. Mild Cognitive Impairment

    MedlinePLUS

    About Alzheimer's Disease: Mild Cognitive Impairment Mild cognitive impairment (MCI) is a condition in which people have memory or other ... as severe as those seen in people with Alzheimer’s disease. More older people with MCI, compared with those ...

  11. myReader: an Auto-Reader for Low Vision Users

    Microsoft Academic Search

    Phillip Pearson; Paul Seakins; David Lee; Nigel Tucker; Darryl Sherwood

    Until recently, video magnifiers - closed-circuit television systems allowing magnification and colour modification - were the most effective reading aid for the visually impaired. Humanware Ltd. has developed a practical portable consumer device, myReader, incorporating a high resolution digital image sensor and document analysis software capable of understanding complex Manhattan layouts. In addition to typical video magnifier functionality, myReader can

  12. Synthetic Vision Systems

    NASA Technical Reports Server (NTRS)

    Prinzel, L.J.; Kramer, L.J.

    2009-01-01

    A synthetic vision system is an aircraft cockpit display technology that presents the visual environment external to the aircraft using computer-generated imagery in a manner analogous to how it would appear to the pilot if forward visibility were not restricted. The purpose of this chapter is to review the state of synthetic vision systems, and discuss selected human factors issues that should be considered when designing such displays.

  13. Active Computer Vision System

    Microsoft Academic Search

    Dietrich Paulus; Christopher Drexler; Michael Reinhold; Matthias Zobel; Joachim Denzler

    2000-01-01

    We present a modular architecture for image understanding and active computer vision which consists of the following major components: Sensor and actor interfaces required for data-driven active vision are encap- sulated to hide machine-dependent parts; image segmentation is implemented in object-oriented programming as a hierarchy of image operator classes, guaranteeing simp le and uniform interfaces. We apply this architecture to

  14. Predictive Robot Vision

    Microsoft Academic Search

    Thomas Achtemichuk

    2006-01-01

    Professor Benjamin and I designed and implemented a fast predictive vision system for a mobile robot, as part of a multi-year research project with two other universities: Brigham Young University and Fordham University. The vision system represents the robot's environment with a 3D gaming platform. Our system uses two Firewire cameras mounted in a pan-tilt base. I personally designed and

  15. CMSC 426: Image Processing (Computer Vision)

    E-print Network

    Jacobs, David

    CMSC 426: Image Processing (Computer Vision) David Jacobs Today's class · What is vision · What is computer vision · Layout of the class #12;Vision · ``to know what is where, by looking.'' (Marr). · Where · What Why is Vision Interesting? · Psychology ­ ~ 50% of cerebral cortex is for vision. ­ Vision is how

  16. Biofeedback for Better Vision

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Biofeedtrac, Inc.'s Accommotrac Vision Trainer, invented by Dr. Joseph Trachtman, is based on vision research performed by Ames Research Center and a special optometer developed for the Ames program by Stanford Research Institute. In the United States, about 150 million people are myopes (nearsighted), who tend to overfocus when they look at distant objects causing blurry distant vision, or hyperopes (farsighted), whose vision blurs when they look at close objects because they tend to underfocus. The Accommotrac system is an optical/electronic system used by a doctor as an aid in teaching a patient how to contract and relax the ciliary body, the focusing muscle. The key is biofeedback, wherein the patient learns to control a bodily process or function he is not normally aware of. Trachtman claims a 90 percent success rate for correcting, improving or stopping focusing problems. The Vision Trainer has also proved effective in treating other eye problems such as eye oscillation, cross eyes, and lazy eye and in professional sports to improve athletes' peripheral vision and reaction time.

  17. Survey of colourings and preservatives in drugs.

    PubMed Central

    Pollock, I.; Young, E.; Stoneham, M.; Slater, N.; Wilkinson, J. D.; Warner, J. O.

    1989-01-01

    OBJECTIVE--To assess the prevalence of colourings and preservatives in drug formulations in the United Kingdom. DESIGN--Postal survey. PARTICIPANTS--All pharmaceutical manufacturers in the United Kingdom were requested to supply data on drug formulations with particular regard to the content of colourings and preservatives. MAIN OUTCOME MEASURE--Prevalence in proprietary drugs of colourings or preservatives, or both, that have been implicated in adverse reactions. Computation of a list of formulations of bronchodilators, antihistamines, and antibiotics that are free of such additives. RESULTS--A total of 118 out of 120 pharmaceutical companies supplied the data requested. In all, 2204 drug formulations were analysed and found to contain 419 different additives, of which 52 were colourings and preservatives that have been implicated in adverse reactions; 930 formulations contained such an additive. Tartrazine was the fourth most commonly occurring colouring, being present in 124 drug formulations. CONCLUSION--Many drugs contain additives that help to identify them and prolong their shelf life but are implicated in adverse reactions in some people. Some form of labelling of drug additives would enable these people to avoid drugs containing such additives. PMID:2508849

  18. Multi-Colour Braid-Monoid Algebras

    E-print Network

    Uwe Grimm; Paul A. Pearce

    1993-03-30

    We define multi-colour generalizations of braid-monoid algebras and present explicit matrix representations which are related to two-dimensional exactly solvable lattice models of statistical mechanics. In particular, we show that the two-colour braid-monoid algebra describes the Yang-Baxter algebra of the critical dilute A-D-E models which were recently introduced by Warnaar, Nienhuis, and Seaton as well as by Roche. These and other solvable models related to dense and dilute loop models are discussed in detail and it is shown that the solvability is a direct consequence of the algebraic structure. It is conjectured that the Yang-Baxterization of general multi-colour braid-monoid algebras will lead to the construction of further solvable lattice models.

  19. The impact of age-related visual impairment on functional independence in the elderly.

    PubMed

    Swagerty, D L

    1995-01-01

    Low vision is an extremely common problem in the elderly, which may have devastating consequences for functional independence and health status. It ranks only behind arthritis and heart disease as the etiology for impaired function in those over the age of 70. Macular degeneration is a leading cause of blindness and poor vision in the elderly. The central vision loss of this disorder can sometimes be postponed through laser therapy. Otherwise, the low visual state is best addressed with vision-enhancing devices, non-optical adaptive equipment, and patient education available through most occupational therapists. Referral to a low-vision rehabilitation program is sometimes needed for more comprehensive evaluation and intervention. Individual adaptation and supportive services often result in a significant improvement in function and quality of life for those elders with low vision. PMID:7666637

  20. Multi-colour detection of gravitational arcs

    NASA Astrophysics Data System (ADS)

    Maturi, Matteo; Mizera, Sebastian; Seidel, Gregor

    2014-07-01

    Strong gravitational lensing provides fundamental insights into the understanding of the dark matter distribution in massive galaxies, galaxy clusters, and the background cosmology. Despite their importance, few gravitational arcs have been discovered so far. The urge for more complete, large samples and unbiased methods of selecting candidates increases. Several methods for the automatic detection of arcs have been proposed in the literature, but large amounts of spurious detections retrieved by these methods force observers to visually inspect thousands of candidates per square degree to clean the samples. This approach is largely subjective and requires a huge amount of checking by eye, especially considering the actual and upcoming wide-field surveys, which will cover thousands of square degrees. In this paper we study the statistical properties of the colours of gravitational arcs detected in the 37 deg2 of the CFHTLS-Archive-Research Survey (CARS). Most of them lie in a relatively small region of the (g' - r', r' - i') colour-colour diagram. To explain this property, we provide a model that includes the lensing optical depth expected in a ?CDM cosmology that, in combination with the sources' redshift distribution of a given survey, in our case CARS, peaks for sources at redshift z ~ 1. By furthermore modelling the colours derived from the spectral energy distribution of the galaxies that dominate the population at that redshift, the model reproduces the observed colours well. By taking advantage of the colour selection suggested by both data and model, we automatically detected 24 objects out of 90 detected by eye checking. Compared with the single-band arcfinder, this multi-band filtering returns a sample complete to 83% and a contamination reduced by a factor of ~6.5. New gravitational arc candidates are also proposed.

  1. Measuring the colour of rendering mortars

    NASA Astrophysics Data System (ADS)

    Govaerts, Yves; Meulebroeck, Wendy; Verdonck, Ann; de Bouw, Michael

    2014-05-01

    When restoring decorative mortar layers on historic façades, professionals need to determine the colour of these finishes in order to select an appropriate repair mortar. Currently, the appearance of these renders is only assessed from a subjective point of view. To match with the aesthetic aspects of the façade, contractors must constantly adjust their repair mortar composition to avoid a patchwork of different colours, which is detrimental for heritage. This time-consuming (trial-and-error) methodology can be excluded by evaluating `colour' with an objective numerical approach. The challenge of the research was to define and evaluate optimal material dependent boundary conditions for measuring the colour of nonhomogeneous mortars. Four samples with different scale of heterogeneity were measured by two spectrocolorimeters, both with a diffuse illumination geometry. The results were plotted in CIE-L*a*b* colour space. By calculating the colour difference (?E*), the influence of measuring with or without specular component was evaluated. We discovered the minimal number of measuring points depends on the scale of heterogeneity and the aperture area. The less homogeneous the mortar sample is and the smaller the aperture area, the more unique measuring points are required. Therefore, it is recommended to choose an aperture head of 25 mm or more to reduce the number of measurements, making your work time-efficient. However, in order to obtain accurate measurements on site, a portable optical spectrum analyser can be used with a 6 mm-diameter aperture, a viewing angle of 10°, SCI mode, illumination source D65, considering a minimum of 15 unique measuring points.

  2. Colour-Temperature Correspondences: When Reactions to Thermal Stimuli Are Influenced by Colour

    PubMed Central

    Ho, Hsin-Ni; Van Doorn, George H.; Kawabe, Takahiro; Watanabe, Junji; Spence, Charles

    2014-01-01

    In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant’s responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented. PMID:24618675

  3. Pitfalls in colour photography of choroidal tumours

    PubMed Central

    Schalenbourg, A; Zografos, L

    2013-01-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

  4. Blue colour preference in honeybees distracts visual attention for learning closed shapes.

    PubMed

    Morawetz, Linde; Svoboda, Alexander; Spaethe, Johannes; Dyer, Adrian G

    2013-10-01

    Spatial vision is an important cue for how honeybees (Apis mellifera) find flowers, and previous work has suggested that spatial learning in free-flying bees is exclusively mediated by achromatic input to the green photoreceptor channel. However, some data suggested that bees may be able to use alternative channels for shape processing, and recent work shows conditioning type and training length can significantly influence bee learning and cue use. We thus tested the honeybees' ability to discriminate between two closed shapes considering either absolute or differential conditioning, and using eight stimuli differing in their spectral characteristics. Consistent with previous work, green contrast enabled reliable shape learning for both types of conditioning, but surprisingly, we found that bees trained with appetitive-aversive differential conditioning could additionally use colour and/or UV contrast to enable shape discrimination. Interestingly, we found that a high blue contrast initially interferes with bee shape learning, probably due to the bees innate preference for blue colours, but with increasing experience bees can learn a variety of spectral and/or colour cues to facilitate spatial learning. Thus, the relationship between bee pollinators and the spatial and spectral cues that they use to find rewarding flowers appears to be a more rich visual environment than previously thought. PMID:23918312

  5. Efficient detection of wound-bed and peripheral skin with statistical colour models.

    PubMed

    Veredas, Francisco J; Mesa, Héctor; Morente, Laura

    2015-04-01

    A pressure ulcer is a clinical pathology of localised damage to the skin and underlying tissue caused by pressure, shear or friction. Reliable diagnosis supported by precise wound evaluation is crucial in order to success on treatment decisions. This paper presents a computer-vision approach to wound-area detection based on statistical colour models. Starting with a training set consisting of 113 real wound images, colour histogram models are created for four different tissue types. Back-projections of colour pixels on those histogram models are used, from a Bayesian perspective, to get an estimate of the posterior probability of a pixel to belong to any of those tissue classes. Performance measures obtained from contingency tables based on a gold standard of segmented images supplied by experts have been used for model selection. The resulting fitted model has been validated on a training set consisting of 322 wound images manually segmented and labelled by expert clinicians. The final fitted segmentation model shows robustness and gives high mean performance rates [(AUC: .9426 (SD .0563); accuracy: .8777 (SD .0799); F-score: 0.7389 (SD .1550); Cohen's kappa: .6585 (SD .1787)] when segmenting significant wound areas that include healing tissues. PMID:25564183

  6. VisionBlocks: A Social Computer Vision Framework

    E-print Network

    Bendale, Abhijit

    Vision Blocks (http://visionblocks.org) is an on demand, in-browser, customizable computer vision application publishing platform for masses. It empowers end-users (consumers)to create novel solutions for themselves that ...

  7. Impact of Cataract Surgery in Reducing Visual Impairment: A Review

    PubMed Central

    Khandekar, Rajiv; Sudhan, Anand; Jain, B. K.; Deshpande, Madan; Dole, Kuldeep; Shah, Mahul; Shah, Shreya

    2015-01-01

    Purpose: The aim was to assess the impact of cataract surgeries in reducing visual disabilities and factors influencing it at three institutes of India. Materials and Methods: A retrospective chart review was performed in 2013. Data of 4 years were collected on gender, age, residence, presenting a vision in each eye, eye that underwent surgery, type of surgery and the amount the patient paid out of pocket for surgery. Visual impairment was categorized as; absolute blindness (no perception of light); blind (<3/60); severe visual impairment (SVI) (<6/60-3/60); moderate visual impairment (6/18-6/60) and; normal vision (?6/12). Statistically analysis was performed to evaluate the association between visual disabilities and demographics or other possible barriers. The trend of visual impairment over time was also evaluated. We compared the data of 2011 to data available about cataract cases from institutions between 2002 and 2009. Results: There were 108,238 cataract cases (50.6% were female) that underwent cataract surgery at the three institutions. In 2011, 71,615 (66.2%) cases underwent surgery. There were 45,336 (41.9%) with presenting vision < 3/60 and 75,393 (69.7%) had SVI in the fellow eye. Blindness at presentation for cataract surgery was associated to, male patients, Institution 3 (Dristi Netralaya, Dahod) surgeries after 2009, cataract surgeries without Intra ocular lens implant implantation, and patients paying <25 US $ for surgery. Predictors of SVI at time of cataract surgery were, male, Institution 3 (OM), phaco surgeries, those opting to pay 250 US $ for cataract surgeries. Conclusion: Patients with cataract seek eye care in late stages of visual disability. The goal of improving vision related quality of life for cataract patients during the early stages of visual impairment that is common in industrialized countries seems to be non-attainable in the rural India. PMID:25624679

  8. Adjustable typography: an approach to enhancing low vision text accessibility.

    PubMed

    Arditi, Aries

    2004-04-15

    Millions of people have low vision, a disability condition caused by uncorrectable or partially correctable disorders of the eye. The primary goal of low vision rehabilitation is increasing access to printed material. This paper describes how adjustable typography, a computer graphic approach to enhancing text accessibility, can play a role in this process, by allowing visually-impaired users to customize fonts to maximize legibility according to their own visual needs. Prototype software and initial testing of the concept is described. The results show that visually-impaired users tend to produce a variety of very distinct fonts, and that the adjustment process results in greatly enhanced legibility. But this initial testing has not yet demonstrated increases in legibility over and above the legibility of highly legible standard fonts such as Times New Roman. PMID:15204299

  9. Visual–vestibular interaction during goal directed locomotion: effects of aging and blurring vision

    Microsoft Academic Search

    Nandini Deshpande; Aftab E. Patla

    2007-01-01

    Normal vision overrides perturbed vestibular information for the optimization of performance during goal directed locomotion, suggesting down-regulation of vestibular gain. However, it is not known if the responses to vestibular perturbation are accentuated when vision is impaired. Furthermore, both visual and vestibular systems deteriorate with age. It is not clear, however, how age-related decline in these sensory systems influences visual–vestibular

  10. Overview of sports vision

    NASA Astrophysics Data System (ADS)

    Moore, Linda A.; Ferreira, Jannie T.

    2003-03-01

    Sports vision encompasses the visual assessment and provision of sports-specific visual performance enhancement and ocular protection for athletes of all ages, genders and levels of participation. In recent years, sports vision has been identified as one of the key performance indicators in sport. It is built on four main cornerstones: corrective eyewear, protective eyewear, visual skills enhancement and performance enhancement. Although clinically well established in the US, it is still a relatively new area of optometric specialisation elsewhere in the world and is gaining increasing popularity with eyecare practitioners and researchers. This research is often multi-disciplinary and involves input from a variety of subject disciplines, mainly those of optometry, medicine, physiology, psychology, physics, chemistry, computer science and engineering. Collaborative research projects are currently underway between staff of the Schools of Physics and Computing (DIT) and the Academy of Sports Vision (RAU).

  11. Integrating National Space Visions

    NASA Technical Reports Server (NTRS)

    Sherwood, Brent

    2006-01-01

    This paper examines value proposition assumptions for various models nations may use to justify, shape, and guide their space programs. Nations organize major societal investments like space programs to actualize national visions represented by leaders as investments in the public good. The paper defines nine 'vision drivers' that circumscribe the motivations evidently underpinning national space programs. It then describes 19 fundamental space activity objectives (eight extant and eleven prospective) that nations already do or could in the future use to actualize the visions they select. Finally the paper presents four contrasting models of engagement among nations, and compares these models to assess realistic pounds on the pace of human progress in space over the coming decades. The conclusion is that orthogonal engagement, albeit unlikely because it is unprecedented, would yield the most robust and rapid global progress.

  12. Testing the AUDI2000 colour-difference formula for solid colours using some visual datasets with usefulness to automotive industry

    NASA Astrophysics Data System (ADS)

    Martínez-García, Juan; Melgosa, Manuel; Gómez-Robledo, Luis; Li, Changjun; Huang, Min; Liu, Haoxue; Cui, Guihua; Luo, M. Ronnier; Dauser, Thomas

    2013-11-01

    Colour-difference formulas are tools employed in colour industries for objective pass/fail decisions of manufactured products. These objective decisions are based on instrumental colour measurements which must reliably predict the subjective colour-difference evaluations performed by observers' panels. In a previous paper we have tested the performance of different colour-difference formulas using the datasets employed at the development of the last CIErecommended colour-difference formula CIEDE2000, and we found that the AUDI2000 colour-difference formula for solid (homogeneous) colours performed reasonably well, despite the colour pairs in these datasets were not similar to those typically employed in the automotive industry (CIE Publication x038:2013, 465-469). Here we have tested again AUDI2000 together with 11 advanced colour-difference formulas (CIELUV, CIELAB, CMC, BFD, CIE94, CIEDE2000, CAM02-UCS, CAM02-SCD, DIN99d, DIN99b, OSA-GP-Euclidean) for three visual datasets we may consider particularly useful to the automotive industry because of different reasons: 1) 828 metallic colour pairs used to develop the highly reliable RIT-DuPont dataset (Color Res. Appl. 35, 274-283, 2010); 2) printed samples conforming 893 colour pairs with threshold colour differences (J. Opt. Soc. Am. A 29, 883-891, 2012); 3) 150 colour pairs in a tolerance dataset proposed by AUDI. To measure the relative merits of the different tested colour-difference formulas, we employed the STRESS index (J. Opt. Soc. Am. A 24, 1823-1829, 2007), assuming a 95% confidence level. For datasets 1) and 2), AUDI2000 was in the group of the best colour-difference formulas with no significant differences with respect to CIE94, CIEDE2000, CAM02-UCS, DIN99b and DIN99d formulas. For dataset 3) AUDI2000 provided the best results, being statistically significantly better than all other tested colour-difference formulas.

  13. Grounding Our Vision: Brain Research and Strategic Vision

    ERIC Educational Resources Information Center

    Walker, Mike

    2011-01-01

    While recognizing the value of "vision," it could be argued that vision alone--at least in schools--is not enough to rally the financial and emotional support required to translate an idea into reality. A compelling vision needs to reflect substantive, research-based knowledge if it is to spark the kind of strategic thinking and insight capable of…

  14. Computational vision models of early vision for target acquisition

    Microsoft Academic Search

    Grant R. Gerhart; Thomas J. Meitzler; Euijung Sohn

    1995-01-01

    Target acquisition methodology for infrared (IR) and visual man-in-the-loop imaging sensors has several limitations for many sensor performance assessment applications. Recent advances in computational vision modeling (CVM) have made dramatic improvements in the understanding of early human vision processes. A simple model of neural receptive fields consists of a generic image representation of the spatial processing characteristics for early vision

  15. Bio-inspired vision

    NASA Astrophysics Data System (ADS)

    Posch, C.

    2012-01-01

    Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980`s, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ``neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems, if they are to succeed in demanding applications such as autonomous robot navigation, micro-manipulation or high-speed tracking, must exploit the power of the asynchronous, frame-free, biomimetic approach.

  16. New Evidence for Infant Colour Categories

    ERIC Educational Resources Information Center

    Franklin, Anna; Davies, Ian R. L.

    2004-01-01

    Bornstein, Kessen, and Weiskopf (1976) reported that pre-linguistic infants perceive colour categorically for primary boundaries: Following habituation, dishabituation only occurred if the test stimulus was from a different adult category to the original. Here, we replicated this important study and extended it to include secondary boundaries,…

  17. Colour pattern modification by coldshock in Lepidoptera.

    PubMed

    Nijhout, H F

    1984-06-01

    When young pupae of Vanessa cardui, V. virginiensis and Precis coenia (Lepidoptera: Nymphalidae) are exposed to severe coldshock many develop aberrant adult wing patterns. For each species, a synchronous cohort of experimental animals always develops a broad range of aberrant pattern morphologies but these can always be arranged in a single unbranched morphological series. When such phenotypic series are compared, between species and between wing surfaces within a species (each wing surface usually bears a different colour pattern), many parallel modifications and trends become evident. These parallelisms reveal certain homologies of pattern elements and suggest that a common physiology underlies the development of a considerable diversity of normal and aberrant colour patterns. The case is made that the phenotypic series produced may represent either a series of sequential stages in colour pattern determination or, a series of quantitatively different 'interpretations' of an established gradient system. Colour pattern morphoclines reveal which patterns are developmentally 'adjacent' to one another and may therefore prove useful in elucidating the evolution of patterns. PMID:6470611

  18. Dual string with U(1) colour symmetry

    Microsoft Academic Search

    M. Ademollo; L. Brink; A. D'Adda; R. D'Auria; E. Napolitano; S. Sciuto; E. del Giudice; P. di Vecchia; S. Ferrara; F. Gliozzi; R. Musto; R. Pettorino; J. H. Schwarz

    1976-01-01

    The string model with a U(1) colour symmetry is analyzed in detail. It is shown that the critical dimension of this model is D = 2. There are no tachyons in the U(1) string. Moreover the massless ground state is the only physical particle of the spectrum. All other states are decoupled because of the gauge conditions. The n-point amplitudes

  19. Colour Coherence in Photon Induced Reactions

    E-print Network

    A. Lebedev; L. Sinclair; E. Strickland; J. Vazdik

    1996-09-04

    Colour coherence in hard photoproduction is considered using the Monte Carlo event generators PYTHIA and HERWIG. Significant effects in the parton shower are found using multijet observables for direct and resolved photon induced reactions. The particle flow in the interjet region of direct processes shows a strong influence of string fragmentation effects.

  20. Colour-responsive fluorescent oxy radical sensors.

    PubMed

    Yucel, Baris; Sanli, Bahar; Akbulut, Huseyin; Ozbey, Suheyla; Benniston, Andrew C

    2012-03-01

    A series of fluorene-fused benzoquinones (Q1-Q5) were prepared by thermolysis of 4-fluorenyl-4-hydroxycyclobutenones. Red fluorescence observed for Q2 is switched by reduction to blue fluorescence by formation of the hydroquinone. Reaction with hydrogen peroxide restores the original fluorescence colour. The potential use of compound Q2 as a reactive oxygen species detector is discussed. PMID:22222712

  1. All the colours of the rainbow

    NASA Astrophysics Data System (ADS)

    Smithson, Hannah E.; Gasper, Giles E. M.; McLeish, Tom C. B.

    2014-08-01

    Our perception of colour has always been a source of fascination, so it's little wonder that studies of the phenomenon date back hundreds of years. What, though, can modern scientists learn from medieval literature -- and how do we go about it?

  2. Colour thresholding and objective quantification in bioimaging

    NASA Technical Reports Server (NTRS)

    Fermin, C. D.; Gerber, M. A.; Torre-Bueno, J. R.

    1992-01-01

    Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples.

  3. Quantum entanglement of quark colour states

    SciTech Connect

    Buividovich, P. V. [JIPNR, National Academy of Science, 220109 Belarus, Minsk, Acad. Krasin str. 99 (Belarus); ITEP, 117218 Russia, Moscow, B. Cheremushkinskaya str. 25 (Russian Federation); Kuvshinov, V. I. [JIPNR, National Academy of Science, 220109 Belarus, Minsk, Acad. Krasin str. 99 (Belarus)

    2010-03-24

    An analysis of quantum entanglement between the states of static colour charges in the vacuum of pure Yang-Mills theory is carried out. Hilbert space of physical states of the fields and the charges is endowed with a direct product structure by attaching an infinite Dirac string to each charge.

  4. Further success of the colour dipole model

    E-print Network

    J. R. Forshaw; R. Sandapen; G. Shaw

    2006-10-16

    We confront a very wide body of HERA diffractive electroproduction data with the predictions of the colour dipole model. We focus upon three different parameterisations of the dipole scattering cross-section and find good agreement for all observables. There can be no doubting the success of the dipole scattering approach and more precise observations are needed in order to expose its limitations.

  5. Contact Lenses for Vision Correction

    MedlinePLUS

    ... Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Pink Eye (Conjunctivitis) Presbyopia (Aging Eye) Stye ... to correct the same conditions that eyeglasses do: myopia (nearsightedness) , hyperopia (farsightedness) , astigmatism (blurred vision due to ...

  6. Clinical Trials in Vision Research

    MedlinePLUS

    ... nih.gov Clinical trials in vision research have led to new medications, surgeries, and methods for disease ... your questions. Clinical trials in vision research have led to new medications, surgeries, and methods for disease ...

  7. Telescopic vision contact lens

    NASA Astrophysics Data System (ADS)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  8. Night Vision Camera

    NASA Technical Reports Server (NTRS)

    1996-01-01

    PixelVision, Inc. developed the Night Video NV652 Back-illuminated CCD Camera, based on the expertise of a former Jet Propulsion Laboratory employee and a former employee of Scientific Imaging Technologies, Inc. The camera operates without an image intensifier, using back-illuminated and thinned CCD technology to achieve extremely low light level imaging performance. The advantages of PixelVision's system over conventional cameras include greater resolution and better target identification under low light conditions, lower cost and a longer lifetime. It is used commercially for research and aviation.

  9. Robotics Peripheral Vision

    NSDL National Science Digital Library

    VU Bioengineering RET Program,

    This unit is designed for advanced programming classes. It leads students through a study of human vision and computer programming simulation. Students apply their previous knowledge of arrays and looping structures to implement a new concept of linked lists and RGB decomposition in order to solve the unit's Grand Challenge: writing a program to simulate peripheral vision by merging two images. This unit connects computer science to engineering by incorporating several science topics (eye anatomy, physics of light and color, mathematics, and science of computers) and guides students through the design process in order to create final simulations.

  10. Tooth root colour as a measure of chronological age.

    PubMed

    Lackovic, K P; Wood, R E

    2000-12-01

    The purpose of this study was to assess a possible colour shift in the root surfaces of adult human teeth and if so, whether this colour change is related to chronological age. Teeth extracted from persons of known age and gender were obtained from Ontario dental practitioners and grouped into five-year age ranges. Three experiments were undertaken: (1) to identify a possible difference in yellow colouration between the four surfaces of tooth roots (mesial, distal, lingual, and buccal), (2) to investigate the difference in yellow colouration of tooth roots between non-molar teeth and molar teeth and (3) to assess the correlation between the age of teeth and root colour saturation for yellow, magenta, cyan and black. The teeth in all investigations were scanned by a flat-bed digital colour scanner with a Kodak colour scale control and viewed on a colour computer monitor. In the first two experiments the yellow colour saturation of the root surfaces was measured at six points on each root using Photoshop 5.0 software. A significant difference was observed in the percentage yellow colour saturation between the mesial and the other three anatomical surfaces (p < 0.01), and between the root surfaces of non-molar and molar teeth (p < 0.01) (ANOVA with Bonferroni post-test). The authors then randomly assigned tooth surfaces to select an equivalent number of posterior and anterior teeth in the study, assessing the relationship between age and root colouration. Four points of colour measurement on 40 teeth (sample size permitting, see Table 1) for each known age and gender were assessed for colour saturation (cyan, magenta, yellow and black). The correlation of chronological age to colour saturation was linear for all colours, with correlation coefficients ranging from r = 0.81 to r = 0.94. The high correlation values strongly support the conclusion that chronological age is related to increased root colouration. PMID:11324269

  11. The cause of 50 million-year-old colour.

    PubMed

    Parker, Andrew R; McKenzie, David R

    2003-11-01

    Multilayer reflectors cause structural, 'metallic' colours in a diversity of animals today, yet are unknown in extinct species. We identify a multilayer reflector, causing structural colour, in a 50-million-year-old beetle from Messel, Germany. It is proposed that the original material of this reflector has been preserved, although this is not a precondition for determining original colours from ancient multilayer reflectors. Therefore, the potential exists to reveal the original colours of other (particularly arthropod) extinct species. PMID:14667366

  12. Differentiation in a tropical deceptive orchid: colour polymorphism and beyond

    Microsoft Academic Search

    Nicolas Juillet; Roxane Delle-Vedove; Laurent Dormont; Bertrand Schatz; Thierry Pailler

    2010-01-01

    Colour polymorphism has often been described among individuals of deceptive orchid species, and several studies have investigated\\u000a reproductive success variations among colour morphs. However, whether colour morphs differed in other traits has received\\u000a little attention in previous studies. Here, we report the case of a tropical deceptive orchid in Reunion Island that exhibits\\u000a three different colour varieties. We investigated patterns

  13. What weta want: colour preferences of a frugivorous insect

    Microsoft Academic Search

    Nik Fadzly; K. C. Burns

    2010-01-01

    Plants use colours as signals to attract mutualists and repel antagonists. Fleshy-fruits are often conspicuously coloured\\u000a to signal different types of information including fruit maturity and spatial location. Previous work on fruit colour selection\\u000a focus on large diurnal vertebrates, yet fruit colours are perceived differently by frugivores with different types of visual\\u000a systems. Here, we tested whether a nocturnal, frugivorous,

  14. Haptic Identification of Raised-Line Drawings When Categorical Information Is Given: A Comparison between Visually Impaired and Sighted Children

    ERIC Educational Resources Information Center

    Picard, Delphine; Albaret, Jean-Michel; Mazella, Anaïs

    2014-01-01

    Research into haptic picture perception has mostly concerned adult participants, and little is known about haptic picture perception in visually impaired and sighted children. In the present study, we compared 13 visually impaired children (early blind and low vision) aged 9-10 years and 13 agematched blindfolded sighted children on their ability…

  15. Evolution of ultraviolet vision in the largest avian radiation - the passerines

    PubMed Central

    2011-01-01

    Background Interspecific variation in avian colour vision falls into two discrete classes: violet sensitive (VS) and ultraviolet sensitive (UVS). They are characterised by the spectral sensitivity of the most shortwave sensitive of the four single cones, the SWS1, which is seemingly under direct control of as little as one amino acid substitution in the cone opsin protein. Changes in spectral sensitivity of the SWS1 are ecologically important, as they affect the abilities of birds to accurately assess potential mates, find food and minimise visibility of social signals to predators. Still, available data have indicated that shifts between classes are rare, with only four to five independent acquisitions of UV sensitivity in avian evolution. Results We have classified a large sample of passeriform species as VS or UVS from genomic DNA and mapped the evolution of this character on a passerine phylogeny inferred from published molecular sequence data. Sequencing a small gene fragment has allowed us to trace the trait changing from one stable state to another through the radiation of the passeriform birds. Their ancestor is hypothesised to be UVS. In the subsequent radiation, colour vision changed between UVS and VS at least eight times. Conclusions The phylogenetic distribution of SWS1 cone opsin types in Passeriformes reveals a much higher degree of complexity in avian colour vision evolution than what was previously indicated from the limited data available. Clades with variation in the colour vision system are nested among clades with a seemingly stable VS or UVS state, providing a rare opportunity to understand how an ecologically important trait under simple genetic control may co-evolve with, and be stabilised by, associated traits in a character complex. PMID:22024316

  16. Colour-scent associations in a tropical orchid: three colours but two odours.

    PubMed

    Delle-Vedove, Roxane; Juillet, Nicolas; Bessière, Jean-Marie; Grison, Claude; Barthes, Nicolas; Pailler, Thierry; Dormont, Laurent; Schatz, Bertrand

    2011-06-01

    Colour and scent are the major pollinator attractants to flowers, and their production may be linked by shared biosynthetic pathways. Species with polymorphic floral traits are particularly relevant to study the joint evolution of floral traits. We used in this study the tropical orchid Calanthe sylvatica from Réunion Island. Three distinct colour varieties are observed, presenting lilac, white or purple flowers, and named respectively C. sylvaticavar.lilacina (hereafter referred as var. lilacina), C. sylvaticavar. alba (var. alba) and C. sylvatica var. purpurea (var. purpurea). We investigated the composition of the floral scent produced by these colour varieties using the non-invasive SPME technique in the wild. Scent emissions are dominated by aromatic compounds. Nevertheless, the presence of the terpenoid (E)-4,8-dimethylnona-1,3,7-triène (DMNT) is diagnostic of var. purpurea, with the volatile organic compounds (VOC) produced by some individuals containing up to 60% of DMNT. We evidence specific colour-scent associations in C. sylvatica, with two distinct scent profiles in the three colour varieties: the lilacina-like profile containing no or very little DMNT (<2%) and the purpurea-like profile containing DMNT (>2%). Calanthe sylvatica var. alba individuals group with one or the other scent profile independently of their population of origin. We suggest that white-flowered individuals have evolved at least twice, once from var. lilacina and at least once from var. purpurea after the colonisation of la Réunion. White-flowered individuals may have been favoured by the particular pollinator fauna characterising the island. These flowering varieties of C. sylvatica, which display three colours but two scents profiles prove that colour is not always a good indicator of odour and that colour-scent associations may be complex, depending on pollination ecology of the populations concerned. PMID:21377705

  17. Cortical Visual Impairment

    MedlinePLUS

    ... for viewing objects at close range and odd angles? • Better vision when viewing moving objects compared to ... tolerated ?• Presentation of visual material from different directions/angles? • Variable level of light in environment (some children ...

  18. On Representation and Matching of MultiColoured Objects

    Microsoft Academic Search

    Jiri Matas; R. Marik; Josef Kittler

    1995-01-01

    A new representation for objects with multiple colours-the colour adjacency graph (CAG)-is proposed. Each node of the CAG represents a single chromatic component of the image defined as a set of pixels forming a unimodal cluster in the chromatic scattergram. Edges encode information about adjacency of colour components and their reflectance ratio. The CAG is related to both the histogram

  19. Then and now: James Clerk Maxwell and colour

    Microsoft Academic Search

    Richard C. Dougal; Clive A. Greated; Alan E. Marson

    2006-01-01

    A survey of the researches of James Clerk Maxwell into the production and perception of colour is presented, and links to a selection of present day applications of colour science are indicated. Although false colour photography was not known in Maxwell's time, aspects of his work, suitably interpreted, have a bearing on the wide applicability of the technique. An outline

  20. Sweep-Line State Space Exploration for Coloured

    E-print Network

    Mailund, Thomas

    Chapter 9 Sweep-Line State Space Exploration for Coloured Petri Nets The paper Sweep-Line State Space Exploration for Coloured Petri Nets pre- sented in this chapter has been published as a workshop changes. 89 #12; 90 Chapter 9. Sweep-Line State Space Exploration for Coloured Petri Nets #12; 9

  1. Colouring Cubic Graphs by Small Steiner Triple Systems

    Microsoft Academic Search

    David P ´

    Given a Steiner triple system S, we say that a cubic graph G is S-colourable if its edges can be coloured by points of S in such way that the colours of any three edges meeting at a vertex form a triple of S. We prove that there is Steiner triple system U of order 21 which is universal in

  2. ORIGINAL PAPER Melanin-based colour polymorphism signals aggressive

    E-print Network

    Lehmann, Laurent

    ORIGINAL PAPER Melanin-based colour polymorphism signals aggressive personality in nest individuals. Because melanin-based colour traits can be associated with life history strategies, differently placed beside their nest. We conclude that melanin- based colouration is a signal of alternative nest

  3. Research article The potential for selection on pollen colour dimorphisms

    E-print Network

    Petanidou, Theodora

    Research article The potential for selection on pollen colour dimorphisms in Nigella degenii: morph in pollen colour and vary extensively in frequency of the two morphs in natural populations. Here we investigate the role of selection on pollen colour during the pollination phase in the two subspecies and its

  4. Inheritance of coat colour in the field spaniel dog

    E-print Network

    Paris-Sud XI, Université de

    Note Inheritance of coat colour in the field spaniel dog R Robinson St Stephens Nursery, Stephens known as roan. dog genetics / coat colour / field spaniel / breed Résumé - Hérédité de la couleur du for the heredity of coat colour in the dog (Little, 1957; Robinson, 1990), it has become apparent as work

  5. Vision Care and the Nation's Children.

    ERIC Educational Resources Information Center

    American Optometric Association, St. Louis, MO.

    Aspects of vision and vision care considered are the following: extent and types of vision defects of American children; importance of vision care in pre-school years, elementary, and secondary school and beyond; and manpower resources in vision care today, the extent of vision testing and care, special problem areas, and governmental support.…

  6. Vision Screening For Head Starters.

    ERIC Educational Resources Information Center

    Foley, Celia

    To determine which children in the Head Start program may have vision problems, Head Start teachers and staff do vision "screening." This booklet demonstrates how to do the screening using the Snellen "E Chart." Trouble signs that the test administrator should be aware of are listed, and vision scores are explained simply. Amblyopia is defined,…

  7. Artificial Vision OBJECT RECOGNITIONOBJECT RECOGNITION

    E-print Network

    Artificial Vision OBJECT RECOGNITIONOBJECT RECOGNITION Dr. Claudio Piciarelli Department of Computer Science University of Udine, ITALY #12;Artificial Vision IntroductionIntroduction · The general;Artificial Vision Feature extractionFeature extraction · For each blob detected in the scene, specific

  8. Artificial Vision CHANGE DETECTIONCHANGE DETECTION

    E-print Network

    Artificial Vision CHANGE DETECTIONCHANGE DETECTION Dr. Claudio Piciarelli Department of Computer Science University of Udine, ITALY #12;Artificial Vision IntroductionIntroduction · The goal of the change;Artificial Vision Introduction (2)Introduction (2) · The main problems of change detection algorithms are due

  9. Active Vision in Artificial Animals

    Microsoft Academic Search

    Demetri Terzopoulos; Tamer F. Rabie

    We propose and demonstrate a new paradigm for active vision re- search that draws upon recent advances in the fields of artificial life and computer graphics. A software alternative to the prevailing hardware vision mindset, animat vision prescribes artificial animals, or animats, situated in physics-based virtual worlds as autonomous virtual robots possessing active perception systems. To be opera- tive in

  10. Registration of Vision 30 Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Vision 30’ (Reg. No. CV-1062, PI 661153) hard red winter (HRW) wheat (Triticum aestivum L.) was developed and tested as VA06HRW-49 and released by the Virginia Agricultural Experiment Station in March 2010. Vision 30 was derived from the cross 92PAN1#33/VA97W-414. Vision 30 is high yielding, awned,...

  11. Purposive and qualitative active vision

    Microsoft Academic Search

    J. Aloimonos

    1990-01-01

    The traditional view of the problem of computer vision as a recovery problem is questioned, and the paradigm of purposive-qualitative vision is offered as an alternative. This paradigm considers vision as a general recognition problem (recognition of objects, patterns or situations). To demonstrate the usefulness of the framework, the design of the Medusa of CVL is described. It is noted

  12. Qudit Colour Codes and Gauge Colour Codes in All Spatial Dimensions

    E-print Network

    Fern H. E. Watson; Earl T. Campbell; Hussain Anwar; Dan E. Browne

    2015-03-30

    Two-level quantum systems, qubits, are not the only basis for quantum computation. Advantages exist in using qudits, d-level quantum systems, as the basic carrier of quantum information. We show that colour codes---a class of topological quantum codes with remarkable transversality properties---can be generalised to the qudit paradigm. In recent developments it was found that in three spatial dimensions a qubit colour code can support a transversal non-Clifford gate, and that in higher spatial dimensions additional non-Clifford gates can be found, saturating Bravyi and K\\"onig's bound [Phys. Rev. Lett. 110, 170503 (2013)]. Furthermore, by using gauge fixing techniques, an effective set of Clifford gates can be achieved, removing the need for state distillation. We show that the qudit colour code can support the qudit analogues of these gates, and show that in higher spatial dimensions a colour code can support a phase gate from higher levels of the Clifford hierarchy which can be proven to saturate Bravyi and K\\"onig's bound in all but a finite number of special cases. The methodology used is a generalisation of Bravyi and Haah's method of triorthogonal matrices [Phys. Rev. A 86 052329 (2012)], which may be of independent interest. For completeness, we show explicitly that the qudit colour codes generalise to gauge colour codes, and share the many of the favourable properties of their qubit counterparts.

  13. Are You Selling the Right Colour? A Cross?cultural Review of Colour as a Marketing Cue

    Microsoft Academic Search

    Mubeen M. Aslam

    2006-01-01

    Should a marketer adopt a pan?cultural or a culture?specific approach when using colour in marketing? Colours exercise powerful effects and induce reactions based on both instincts and associations. Colours alter the meanings of the objects or situations with which they are associated and colour preferences can predict consumers' behaviour. This article reviews the psychological and socio?cultural associations and meanings of

  14. Synthetic Vision Workshop 2

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J. (Compiler)

    1999-01-01

    The second NASA sponsored Workshop on Synthetic/Enhanced Vision (S/EV) Display Systems was conducted January 27-29, 1998 at the NASA Langley Research Center. The purpose of this workshop was to provide a forum for interested parties to discuss topics in the Synthetic Vision (SV) element of the NASA Aviation Safety Program and to encourage those interested parties to participate in the development, prototyping, and implementation of S/EV systems that enhance aviation safety. The SV element addresses the potential safety benefits of synthetic/enhanced vision display systems for low-end general aviation aircraft, high-end general aviation aircraft (business jets), and commercial transports. Attendance at this workshop consisted of about 112 persons including representatives from industry, the FAA, and other government organizations (NOAA, NIMA, etc.). The workshop provided opportunities for interested individuals to give presentations on the state of the art in potentially applicable systems, as well as to discuss areas of research that might be considered for inclusion within the Synthetic Vision Element program to contribute to the reduction of the fatal aircraft accident rate. Panel discussions on topical areas such as databases, displays, certification issues, and sensors were conducted, with time allowed for audience participation.

  15. VISION AND READING ABILITY.

    ERIC Educational Resources Information Center

    MANGRUM, CHARLES T.

    SIGNIFICANT RESEARCH ON THE PHYSIOLOGICAL AND FUNCTIONAL ASPECTS OF VISION AND READING DISABILITY IS SURVEYED. CONCLUSIONS BASED ON THE LITERATURE IN THE FIELD ARE DISCUSSED. A BIBLIOGRAPHY OF 70 REFERENCES AND A GLOSSARY OF TERMS ARE APPENDED. A TABLE SUMMARIZING REFRACTIVE ERRORS AND EYE DEFECTS CONTRIBUTING TO READING DISABILITY IS INCLUDED.…

  16. Color vision test

    MedlinePLUS

    ... less anxious about the test if you explain what will happen and why. Usually there is a sample card of multicolored dots that almost everyone can identify, even people with color vision problems. If you or your child normally wears glasses, wear them ...

  17. BEST VISIONS. BEST INNOVATIONS.

    E-print Network

    Hellebrand, Sybille

    BEST VISIONS. BEST INNOVATIONS. BEST SOLUTIONS: INDUSTRIE 4.0 NRW Cluster Nordrhein INTERNATIONAL KOOPERATIONS- BÖRSE KOMMUNIKATION & NETWORKING FOREN 13:30 - 17:00 Uhr Industrie 4.0 CPS in der.NRW, Geschäftsführer, IMST GmbH Moderation: Anna Planken #12;4 |www.iuk-tag-nrw.de FORUM Industrie 4.0 ­ CPS in der

  18. Two Visions of America

    ERIC Educational Resources Information Center

    Capaldi, Nicholas

    2012-01-01

    Since the seventeenth century, there have been two narratives about modernity in general and America in particular. The author uses the term "narrative" to include (a) facts, (b) arguments, and most important, (c) a larger vision of how one sees the world and chooses to engage the world. The first and originalist narrative is the Lockean Liberty…

  19. Peripheral Vision Lab

    NSDL National Science Digital Library

    VU Bioengineering RET Program,

    Students explore their peripheral vision by reading large letters on index cards. Then they repeat the experiment while looking through camera lenses, first a lens with a smaller focal length and then a lens with a larger focal length. Then they complete a worksheet and explain how the experiment helps them solve the challenge question introduced in lesson 1 of this unit.

  20. Vision as Adaptive Epistemology

    E-print Network

    Ignazio Licata

    2008-11-30

    In the last years the debate on complexity has been developing and developing in transdisciplinary way to meet the need of explanation for highly organized collective behaviors and sophisticated hierarchical arrangements in physical, biological, cognitive and social systems. Unfortunately, no clear definition has been reached, so complexity appears like an anti-reductionist paradigm in search of a theory. In our short survey we aim to suggest a clarification in relation to the notions of computational and intrinsic emergence, and to show how the latter is deeply connected to the new Logical Openness Theory, an original extension of Godel theorems to the model theory. The epistemological scenario we are going to make use of is that of the theory of vision, a particularly instructive one. Vision is an element of our primordial relationship with the world;consequently it comes as no surprise that carefully taking into consideration the processes of visual perception can lead us straight to some significant questions useful to delineate a natural history of knowledge. The common Greek etymological root of theory and vision sounds like a metaphor pointing out the analogy between the modalities of vision and those we use to see and build the world because them both can say us something about the central role of the observer and the semantic complexity of cognitive strategies.

  1. Vision: Essential Scaffolding

    ERIC Educational Resources Information Center

    Murphy, Joseph; Torre, Daniela

    2015-01-01

    Few concepts are more noted in the leadership effects research than vision. It is a cardinal element in the school improvement equation as well. Yet, it remains one of the least well-specified components of that algorithm. Based on a comprehensive review of the research on effective leadership and school improvement from 1995 to 2012, we bring…

  2. Dance: Verities, Values, Visions.

    ERIC Educational Resources Information Center

    Boorman, Joyce, Ed.; Harris, Dorothy, Ed.

    The Binational Dance Conference was organized into three focal themes--verities, values, and visions in dance--to emphasize the known and accepted worth and value of dance, and to stimulate through knowledge and idea exchange, imaginative directions for dance in the future of both the United States and Canada. This thematic structure is also the…

  3. Writing for Night Vision

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2006-01-01

    In this activity (page 1 of the PDF), learners will use a home video camera with a “night vision” mode to test how various inks appear outside the spectrum of visible light. In a darkened room, some messages will be legible with an infrared camera and others will seem to go invisible. Relates to the linked video, DragonflyTV: Forensics.

  4. Idea Bank: Astronomy for Students With Sensory Impairments

    NSDL National Science Digital Library

    Dana Backman

    2009-03-01

    The Space Exploration and Experience (SEE) Project and Yerkes Astrophysics Academy for Young Scientists (YAAYS)--both at the University of Chicago's Yerkes Observatory in Williams Bay, Wisconsin--are designed to promote active learning in astronomy and physical science for all students, including those with vision or hearing impairments. Resources include the Hands-On Universe (HOU) facility and the Stratospheric Observatory for Infrared Astronomy (SOFIA) Active Astronomy (AA) curriculum kits. This Idea Bank discusses these resources, which allow teachers to help all students--with and without sensory impairments--to participate in the 2009 International Year of Astronomy (IYA) experience.

  5. Vision as Bayesian Inference:Vision as Bayesian Inference: Analysis by Synthesis.Analysis by Synthesis.

    E-print Network

    Haykin, Simon

    Vision as Bayesian Inference:Vision as Bayesian Inference: Analysis by Synthesis. ·· Videos/Videos/PDFPDF''ss available for download.available for download. #12;Difficulty of VisionDifficulty of Vision ·· Vision is extremely difficult.Vision is extremely difficult. ·· 50% cortex involved in vision

  6. Honey characterization using computer vision system and artificial neural networks.

    PubMed

    Shafiee, Sahameh; Minaei, Saeid; Moghaddam-Charkari, Nasrollah; Barzegar, Mohsen

    2014-09-15

    This paper reports the development of a computer vision system (CVS) for non-destructive characterization of honey based on colour and its correlated chemical attributes including ash content (AC), antioxidant activity (AA), and total phenolic content (TPC). Artificial neural network (ANN) models were applied to transform RGB values of images to CIE L*a*b* colourimetric measurements and to predict AC, TPC and AA from colour features of images. The developed ANN models were able to convert RGB values to CIE L*a*b* colourimetric parameters with low generalization error of 1.01±0.99. In addition, the developed models for prediction of AC, TPC and AA showed high performance based on colour parameters of honey images, as the R(2) values for prediction were 0.99, 0.98, and 0.87, for AC, AA and TPC, respectively. The experimental results show the effectiveness and possibility of applying CVS for non-destructive honey characterization by the industry. PMID:24767037

  7. The colour of domestication and the designer chicken

    NASA Astrophysics Data System (ADS)

    Sheppy, Andrew

    2011-03-01

    Colour is an important feature of most living organisms. In the wild, colour has great significance affecting the survival and reproductive success of the species. The environmental constraints which lead to the specific colours of birds and animals are very strong and individuals of novel colours tend not to survive. Under domestication, mankind has transformed all the species involved which have thus been freed from environmental pressures to a large extent. Early colour variants were mostly selected for utility reasons or religious practices. In more recent centuries colour varieties have been created purely for ornament and pleasure, fashion playing a surprisingly large part in their development. A bewildering array of colours and patterns can now be found in all our commensal species, especially the Domestic Fowl ( Gallus gallus domesticus).

  8. Colour biases in territorial aggression in a Neotropical cichlid fish.

    PubMed

    Lehtonen, Topi K

    2014-05-01

    Discrete colour morphs have provided important insights into the evolution of phenotypic diversity. One of the mechanisms that can help to explain coexistence of ecologically similar colour morphs and incipient species is (colour) biased aggression, which has the potential to promote continued existence of the morphs in a frequency-dependent manner. I addressed colour biases in territorial aggression in a field-based study on a Neotropical cichlid fish species, Amphilophus sagittae, which has two ecologically indistinguishable colour morphs that mate assortatively. I found that A. sagittae, in particular females, were more aggressive towards models of their own colour than those mimicking colours of the other morph. Such a behavioural pattern should result in a selection regime that benefits the rarer morph, and hence could help explain how novel, rare phenotypes may avoid competitive exclusion. PMID:24414236

  9. Relationship between natural tooth shade and skin colour.

    PubMed

    Nourbakhsh, M; Mousavinejad, N; Adli, A R; Harati, M

    2013-06-01

    The purpose of this study was to assess the correlation of skin colour and tooth shade. One hundred and twenty six individuals aging between 18 to 25 years participated in this study. Colour of the maxillary central incisors was examined by VITA easy shade. Tooth shades were assigned to four ordinal values. Nivea Beauty Protect Foundation shade sample was used as a guide to assess facial skin colour Shin colours were also assigned to four ordinal values. Spearman test revealed that there was a significant relationship between tooth shade and skin colour Total co-relation factor was 51.6% (p <0 .01). Co-relation factors were 57% for women and 27% for men (p <0 .01). The highest tooth shade prevalence belonged to the second group and the highest skin colour prevalence was also in the second skin colour group. PMID:23888526

  10. [Systems analysis of colour music corrective effect].

    PubMed

    Gumeniuk, V A; Batova, N Ia; Mel'nikova, T S; Glazachev, O S; Golubeva, N K; Klimina, N V; Hubner, P

    1998-01-01

    In the context of P. K. Anokhin's theory of functional systems, the corrective effects of various combinations of medical therapeutical resonance music (MTRM) and dynamic colour exposure were analyzed. As compared to rehabilitative music programmes, MRTM was shown to have a more pronounced relaxing effect as manifested both in the optimization of emotion and in the activity of autonomic regulation of cardiovascular functions. On combined MRTM and dynamic colour flow exposures, the relaxing effect is most marked. In the examinees, the personality and situation anxieties diminish, mood improves, cardiovascular parameters become normal, the rate of metabolic processes and muscular rigidity reduce, the spectral power of alpha-rhythm increases, these occurring predominantly in the anterior region of the brain. The findings suggest the high efficiency of the chosen way of normalizing the functional status of man. PMID:9567714

  11. Colour-tunable fluorescent multiblock micelles.

    PubMed

    Hudson, Zachary M; Lunn, David J; Winnik, Mitchell A; Manners, Ian

    2014-01-01

    Emerging strategies based on the self-assembly of block copolymers have recently enabled the bottom-up fabrication of nanostructured materials with spatially distinct functional regions. Concurrently, a drive for further miniaturization in applications such as optics, electronics and diagnostic technology has led to intense interest in nanomaterials with well-defined patterns of emission colour. Using a series of fluorescent block copolymers and the crystallization-driven living self-assembly approach, we herein describe the synthesis of multicompartment micelles in which the emission of each segment can be controlled to produce colours throughout the visible spectrum. This represents a bottom-up synthetic route to objects analogous to nanoscale pixels, into which complex patterns may be written. Because of their small size and high density of encoded information, these findings could lead to the development of new materials for applications in, for example, biological diagnostics, miniaturized display technology and the preparation of encoded nanomaterials with high data density. PMID:24594554

  12. Extracting parameters from Colour-Magnitude Diagrams

    E-print Network

    Bonatto, C; Kepler, S O; Bica, E

    2015-01-01

    We present a simple approach for obtaining robust values of astrophysical parameters from the observed colour-magnitude diagrams (CMDs) of star clusters. The basic inputs are the Hess diagram built with the photometric measurements of a star cluster and a set of isochrones covering wide ranges of age and metallicity. In short, each isochrone is shifted in apparent distance modulus and colour excess until it crosses over the maximum possible Hess density. Repeating this step for all available isochrones leads to the construction of the solution map, in which the optimum values of age and metallicity - as well as foreground/background reddening and distance from the Sun - can be searched for. Controlled tests with simulated CMDs show that the approach is efficient in recovering the input values. We apply the approach to the open clusters M\\,67, NGC\\,6791, and NGC\\,2635, which are characterised by different ages, metallicities and distances from the Sun.

  13. Colour superconductivity in a strong magnetic field

    E-print Network

    Efrain J. Ferrer; Vivian de la Incera; Cristina Manuel

    2005-11-30

    We explore the effects of an applied strong external magnetic field in a three flavour massless colour superconductor. The long-range component of the B field that penetrates the superconductor enhances some quark condensates, leading to a different condensation pattern. The external field also reduces the flavour symmetries in the system, and thus it changes drastically the corresponding low energy physics. Our considerations are relevant for the study of highly magnetized compact stars.

  14. The VRI colours of H II galaxies

    NASA Astrophysics Data System (ADS)

    Telles, Eduardo; Terlevich, Roberto

    1997-03-01

    We present a high spatial resolution CCD surface photometry study in the optical V, R and I broad-band filters of a sample of 15 H II galaxies. Narrow-band imaging allows the separation of the emission-line region from the extended parts of the galaxy. The latter are assumed to represent the underlying galaxy in H II galaxies; thus the colours of the underlying galaxy are measured. The colours of the underlying stellar continuum within the starburst are also derived by subtracting the contribution of the emission lines falling in the broad-band filters. The distribution of colours of the underlying galaxy in H II galaxies is similar to the colours of other late-type low surface brightness galaxies, which suggests a close kinship of these with the quiescent phases of H II galaxies. However, comparison wtih recent evolutionary population synthesis models shows that the observational errors and the uncertainties in the models are still too large to put strict constraints on their past star formation history. Our analysis of the morphology and structural properties, from contour maps and luminosity profiles, of this sample of 15 H II galaxies agrees with what has been found by Telles and Telles, Melnick & Terlevich, namely that H II galaxies comprise two broad classes segregated by their luminosity; Type I H II galaxies are luminous and have disturbed and irregular outer shapes, while Type II H II galaxies are less luminous and have regular shapes. The outer parts of their profiles are well represented by an exponential, as in other types of known dwarf galaxy.

  15. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  16. Tetrachromacy, oil droplets and bird plumage colours

    Microsoft Academic Search

    M. Vorobyev; D. Osorio; A. T. D. Bennett; N. J. Marshall; I. C. Cuthill

    1998-01-01

    There is a growing body of data on avian eyes, including measurements of visual pigment and oil droplet spectral absorption,\\u000a and of receptor densities and their distributions across the retina. These data are sufficient to predict psychophysical colour\\u000a discrimination thresholds for light-adapted eyes, and hence provide a basis for relating eye design to visual needs. We examine\\u000a the advantages of

  17. How to calculate colourful cross sections efficiently

    E-print Network

    Gleisberg, Tanju; Krauss, Frank

    2008-01-01

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  18. How to calculate colourful cross sections efficiently

    E-print Network

    Tanju Gleisberg; Stefan Hoeche; Frank Krauss

    2008-08-27

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  19. Background complexity affects colour preference in bumblebees

    NASA Astrophysics Data System (ADS)

    Forrest, Jessica; Thomson, James D.

    2009-08-01

    Flowers adapted for hummingbird pollination are typically red. This correlation is usually explained by the assertion that nectar- or pollen-stealing bees are “blind” to red flowers. However, laboratory studies have shown that bees are capable of locating artificial red flowers and often show no innate preference for blue over red. We hypothesised that these findings might be artefacts of the simplified laboratory environment. Using bumblebees ( Bombus impatiens) that had been trained to visit red and blue artificial flowers, we tested whether colour preference was influenced by complexity of the background on which they were foraging. Many bees were indifferent to flower colour when tested using a uniform green background like those commonly used in laboratory studies, but all bees showed strong colour preferences (usually for blue) when flowers were presented against a photograph of real foliage. Overall, preference for blue flowers was significantly greater on the more realistic, complex background. These results support the notion that the red of “hummingbird syndrome” flowers can function to reduce bee visits despite the ability of bees to detect red and highlight the need to consider context when drawing inferences about pollinator preferences from laboratory data.

  20. Impairment in Non-Word Repetition: A Marker for Language Impairment or Reading Impairment?

    ERIC Educational Resources Information Center

    Baird, Gillian; Slonims, Vicky; Simonoff, Emily; Dworzynski, Katharina

    2011-01-01

    Aim: A deficit in non-word repetition (NWR), a measure of short-term phonological memory proposed as a marker for language impairment, is found not only in language impairment but also in reading impairment. We evaluated the strength of association between language impairment and reading impairment in children with current, past, and no language…

  1. Artist's colour rendering of HDR scenes in 3D Mondrian colour-constancy experiments

    NASA Astrophysics Data System (ADS)

    Parraman, Carinna E.; McCann, John J.; Rizzi, Alessandro

    2010-01-01

    The presentation provides an update on ongoing research using three-dimensional Colour Mondrians. Two still life arrangements comprising hand-painted coloured blocks of 11 different colours were subjected to two different lighting conditions of a nearly uniform light and directed spotlights. The three-dimensional nature of these test targets adds shadows and multiple reflections, not found in flat Mondrian targets. Working from exactly the same pair of scenes, an author painted them using watercolour inks and paints to recreate both LDR and HDR Mondrians on paper. This provided us with a second set of appearance measurements of both scenes. Here we measured appearances by measuring reflectances of the artist's rendering. Land's Colour Mondrian extended colour constancy from a pixel to a complex scene. Since it used a planar array in uniform illumination, it did not measure the appearances of real life 3-D scenes in non-uniform illumination. The experiments in this paper, by simultaneously studying LDR and HDR renditions of the same array of reflectances, extend Land's Mondrian towards real scenes in non-uniform illumination. The results show that the appearances of many areas in complex scenes do not correlate with reflectance.

  2. An Overview of Dual Sensory Impairment in Older Adults: Perspectives for Rehabilitation

    PubMed Central

    Saunders, Gabrielle H.; Echt, Katharina V.

    2007-01-01

    Dual sensory impairment (DSI) refers to the presence of both hearing loss and vision loss. The occurrence of DSI is particularly prevalent among the aging population, with studies showing between 9% and 21% of adults older than 70 years having some degree of DSI. Despite this, there is little direction regarding recommended clinical practice and rehabilitation of individuals with DSI. It is assumed that the problems encountered by individuals with DSI are considerably greater than the effects of vision impairment or hearing impairment alone, because when these two sensory impairments are combined, the individual is seriously deprived of compensatory strategies that make use of the nonimpaired sense. In this article, the literature available regarding DSI is summarized, and research needs regarding rehabilitation strategies are outlined and discussed. Simple suggestions for addressing DSI are provided that use available tools and technology. PMID:18003868

  3. Hearing or speech impairment - resources

    MedlinePLUS

    Resources - hearing or speech impairment ... The following organizations are good resources for information on hearing impairment or speech impairment: American Speech-Language-Hearing Association - www.asha.org National Dissemination Center for Children ...

  4. Vision North Texas

    E-print Network

    Walz, K.

    2011-01-01

    ?business as usual? ?Vision North Texas and the North Texas 2050 document ?Implications for energy conservation ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 The North Texas Region ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9..., 2011 ? ? FW D 16 County Region for Vision North Texas 5.3M people in 2000; 6.5M in 2010; 9.5M in 2030; 11.7M in 2050 ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 ESL-KT-11...

  5. Dynamic monocular machine vision

    Microsoft Academic Search

    Ernst Dieter Dickmanns; Volker Graefe

    1988-01-01

    A new approach to real-time machine vision in dynamic scenes is presented based on special hardware and methods for feature extraction and information processing. Using integral spatio-temporal models, it by-passes the nonunique inversion of the perspective projection by applying recursive least squares filtering. By prediction error feedback methods similar to those used in modern control theory, all spatial state variables

  6. Military personnel recognition system using texture, colour, and SURF features

    NASA Astrophysics Data System (ADS)

    Irhebhude, Martins E.; Edirisinghe, Eran A.

    2014-06-01

    This paper presents an automatic, machine vision based, military personnel identification and classification system. Classification is done using a Support Vector Machine (SVM) on sets of Army, Air Force and Navy camouflage uniform personnel datasets. In the proposed system, the arm of service of personnel is recognised by the camouflage of a persons uniform, type of cap and the type of badge/logo. The detailed analysis done include; camouflage cap and plain cap differentiation using gray level co-occurrence matrix (GLCM) texture feature; classification on Army, Air Force and Navy camouflaged uniforms using GLCM texture and colour histogram bin features; plain cap badge classification into Army, Air Force and Navy using Speed Up Robust Feature (SURF). The proposed method recognised camouflage personnel arm of service on sets of data retrieved from google images and selected military websites. Correlation-based Feature Selection (CFS) was used to improve recognition and reduce dimensionality, thereby speeding the classification process. With this method success rates recorded during the analysis include 93.8% for camouflage appearance category, 100%, 90% and 100% rates of plain cap and camouflage cap categories for Army, Air Force and Navy categories, respectively. Accurate recognition was recorded using SURF for the plain cap badge category. Substantial analysis has been carried out and results prove that the proposed method can correctly classify military personnel into various arms of service. We show that the proposed method can be integrated into a face recognition system, which will recognise personnel in addition to determining the arm of service which the personnel belong. Such a system can be used to enhance the security of a military base or facility.

  7. Quality of life in patients with visual impairment in Ibadan: a clinical study in primary care

    PubMed Central

    Adigun, Kehinde; Oluleye, Tunji S; Ladipo, Modupe MA; Olowookere, Samuel Anu

    2014-01-01

    Background Visual function is important for optimal orientation in functional and social life, and has an effect on physical and emotional well-being. Visual impairment, therefore, leads to restrictions in all aspects of daily living and is related to quality of life. The aim of this study was to provide information on the causes of visual impairment in patients presenting to their family physician, the spectrum of impairment, and its impact on quality of life for these patients. Methods This descriptive cross-sectional study of 375 adult patients with ocular symptoms was performed in the general outpatient department of the University College Hospital, Ibadan, from July to September, 2009. After checking their presenting visual acuity, the patients were interviewed using the Vision-Related Quality of Life questionnaire to determine the impact of visual impairment on their quality of life. Ophthalmic examinations were performed to determine the causes of visual impairment. The results were analyzed using proportions and percentages. Results The main causes of visual impairment were cataracts (58.7%), refractive error (19.4%), and glaucoma (2.9%). Visual impairment was found to be associated with advancing age, low education, and unemployment (P<0.001). Most patients (85.1%) were found to have good quality of life overall. Quality of life was found to be poor in the domains of visual function (64.2%) and social interaction (50.9%). Quality of life was found to be related to the degree of visual impairment, ie, blind patients reported poor quality of life (41.4%) when compared with those having low vision (8.6%) or near normal vision (2.4%, P<0.001). Conclusion This study identified poor quality of life in patients with a higher degree of visual impairment. Family physicians need to identify these visually impaired patients early and make timely referrals. PMID:24790455

  8. Detection of Defects in Colour Texture Surfaces

    Microsoft Academic Search

    Josef Kittler; R. Marik; Majid Mirmehdi; Maria Petrou; J. Song

    1994-01-01

    An important area of automatic industrial inspection that has been largely overlooked by the recent wave of research in machine vision applications is the detection of defects in textured surfaces. In this paper, we present different algorithms for the detection of surface abnormalities both in the chromatic and structural properties of random tex- tures. We present very promising results on

  9. Anim. Behav., 1997, 54, 13831392 Ultraviolet vision and band-colour preferences in female zebra finches,

    E-print Network

    Swaddle, John

    finches, Taeniopygia guttata SARAH HUNT, INNES C. CUTHILL, JOHN P. SWADDLE & ANDREW T. D. BENNETT Centre acceptance 14 February 1997; final acceptance 8 April 1997; MS. number: 5425) Abstract. Zebra finches have opposite sex conspecifics. For example, in some studies female zebra finches preferred males wearing red

  10. A perceptual interface for vision substitution in a color matching experiment

    Microsoft Academic Search

    Guido Bologna; Benoît Deville; Michel Vinckenbosch; Thierry Pun

    2008-01-01

    In the context of vision substitution by the auditory channel several systems have been introduced. One such system that is presented here, See ColOr, is a dedicated interface part of a mobility aid for visually impaired people. It transforms a small portion of a colored video image into spatialized instrument sounds. In this work the purpose is to verify the

  11. Ability to Read Medication Labels Improved by Participation in a Low Vision Rehabilitation Program

    ERIC Educational Resources Information Center

    Markowitz, Samuel N.; Kent, Christine K.; Schuchard, Ronald A.; Fletcher, Donald C.

    2008-01-01

    Demographic projections indicate that the population of the Western world is aging, and evidence suggests an increase in the incidence of conditions, such as age-related macular degeneration (AMD), that produce visual impairments and result in low vision (Maberley et al., 2006). It is expected that in the United States and Canada, the annual…

  12. Seeing differently... Optogenetics, holography, and vision restoration Lecturer: Inna Reutsky-Gefen

    E-print Network

    Rimon, Elon

    Seeing differently... Optogenetics, holography, and vision restoration Lecturer: Inna Reutsky of the impaired retina that utilizes a new approach recently introduced into neuroscience - Optogenetics. This new-electrode prosthesis. The optogenetic technology that was developed in our laboratory enables stimulation of neuronal

  13. Toward a Collaborative Working Relationship among Vision Rehabilitation and Allied Health Professionals.

    ERIC Educational Resources Information Center

    Orr, Alberta L.; Huebner, Kathleen M.

    2001-01-01

    This article explores issues of allied health professionals who provide vision rehabilitation services to individuals with visual impairments. It questions whether allied health professionals receive sufficient training to work with this population, identifies challenges facing the rehabilitation field, and suggests ways allied health…

  14. Developmental Recapitulation in Adaptation to Vision Loss Among MiddleAge and Older Adults

    Microsoft Academic Search

    Mark Brennan; Thalia MacMillan

    2006-01-01

    Previous research has suggested that a recapitulation of developmental stages occurs during periods of readjustment in situations involving significant contextual or environmental change. The purpose of this paper is to examine if evidence exists for developmental recapitulation among middle-age and older adults adapting to recent vision impairment. Psychosocial development was operationalized in accordance with Erikson's stage theory (Erikson, 1963, 1980)

  15. Promoting a Message on Vision Loss to Diverse Groups of Adults: Research Report

    ERIC Educational Resources Information Center

    Cimarolli, Verena R.; Stuen, Cynthia; Sussman-Skalka, Carol J.

    2006-01-01

    Visual impairment is the second most prevalent disability among older adults (National Center for Health Statistics, 1993), affecting about 2.9 million Americans aged 65 and older (Eye Diseases Prevalence Research Group, 2004). As the population ages, the number of individuals who will experience age-related vision loss will also increase.…

  16. Estimated Number of Persons Eligible for Vision Rehabilitation Services Under Expanded Medicare. Research Report

    ERIC Educational Resources Information Center

    Cavenaugh, Brenda S.; Steinman, Bernard A.

    2005-01-01

    It has been well documented by researchers that the incidence of visual impairment (both blindness and low vision) increases as people age (see, for example, Congdon et al., 2004; Crews, 1994; Lighthouse International, 2001; Rubin, 2000) and that these physical declines can adversely affect an individual's ability to perform activities that…

  17. Mild Cognitive Impairment Research

    MedlinePLUS Videos and Cool Tools

    ... Media Text Size Videos and Media Virtual Library Brain Tour Facts & Figures Spotlight on Researchers Web Links ... early diagnosis Mild Cognitive Impairment Research Inside the brain Genetics in Alzheimer's Advances in brain imaging Diet ...

  18. Specific Language Impairment

    MedlinePLUS

    ... learning disabilities, such as dyslexia, some cases of autism, and speech sound disorders (conditions in which speech ... which are also characteristic of most children with autism spectrum disorders (ASD). Impairments in understanding and the ...

  19. The Vision of William Porterfield

    Microsoft Academic Search

    Nicholas J. Wade

    In eighteenth-century Britain, research on vision was conducted in the context of either optics or medicine, and both were\\u000a influenced by philosophy. These threads were woven together by William Porterfield (ca. 1696–1771) in his essays on eye movements\\u000a and in his treatise on the eye and vision. The scene for investigating vision was set by Isaac Newton (1642–1727) in the

  20. The epistemics of ayahuasca visions

    Microsoft Academic Search

    Benny Shanon

    2010-01-01

    In this paper, I discuss substance-induced visions and consider their epistemic status, meaning, and modes of proper interpretation.\\u000a I focus on the visions induced by ayahuasca, a powerful psychoactive plant-made brew that has had a central status and role\\u000a in the indigenous tribal cultures of the upper Amazonian region. The brew is especially famous for the visions seen with it.

  1. Intelligent robots and computer vision

    SciTech Connect

    Casasent, D.P.

    1986-01-01

    This book presents the papers given at a conference on artificial intelligence and robot vision. Topics considered at the conference included pattern recognition, image processing for intelligent robotics, three-dimensional vision (depth and motion), vision modeling and shape estimation, spatial reasoning, the symbolic processing visual information, robotic sensors and applications, intelligent control architectures for robot systems, robot languages and programming, human-machine interfaces, robotics applications, and architectures of robotics.

  2. Review of night vision technology

    NASA Astrophysics Data System (ADS)

    Chrzanowski, K.

    2013-06-01

    Night vision based on technology of image intensifier tubes is the oldest electro-optical surveillance technology. However, it receives much less attention from international scientific community than thermal imagers or visible/NIR imagers due to series of reasons. This paper presents a review of a modern night vision technology and can help readers to understand sophisticated situation on the international night vision market.

  3. Evolution of ultraviolet vision in shorebirds (Charadriiformes)

    PubMed Central

    Ödeen, Anders; Håstad, Olle; Alström, Per

    2010-01-01

    Diurnal birds belong to one of two classes of colour vision. These are distinguished by the maximum absorbance wavelengths of the SWS1 visual pigment sensitive to violet (VS) and ultraviolet (UVS). Shifts between the classes have been rare events during avian evolution. Gulls (Laridae) are the only shorebirds (Charadriiformes) previously reported to have the UVS type of opsin, but too few species have been sampled to infer that gulls are unique among shorebirds or that Laridae is monomorphic for this trait. We have sequenced the SWS1 opsin gene in a broader sample of species. We confirm that cysteine in the key amino acid position 90, characteristic of the UVS class, has been conserved throughout gull evolution but also that the terns Anous minutus, A. tenuirostris and Gygis alba, and the skimmer Rynchops niger carry this trait. Terns, excluding Anous and Gygis, share the VS conferring serine in position 90 with other shorebirds but it is translated from a codon more similar to that found in UVS shorebirds. The most parsimonious interpretation of these findings, based on a molecular gene tree, is a single VS to UVS shift and a subsequent reversal in one lineage. PMID:20015861

  4. Literacy and visual impairment.

    PubMed

    Erickson, Karen A; Hatton, Deborah

    2007-02-01

    Research supporting specific instructional approaches for young children with visual impairments and blindness is limited. There is, however, a growing body of evidence to support the belief that the critical components of emergent and early conventional literacy for children with visual impairments do not differ markedly from those of their sighted peers. Specifically, infants and toddlers with visual impairments and blindness require interactions that support their oral language development, awareness of print or braille, and opportunities to explore writing. Although these very young children are often delayed in developing emergent literacy understandings, the path of their development is consistent with emergent literacy development of sighted children. The research regarding older children with visual impairments and blindness suggests that they too benefit from instruction that emphasizes the critical elements of early literacy instruction for all children. Research also suggests that specific strategies, such as repeated readings, direct instruction in phonics, and big word decoding that emphasizes morphemes, can benefit school-aged children with visual impairments and blindness. Further research is needed if we are to understand fully the most effective approaches to emergent and early literacy instruction for children with visual impairments and blindness, but there is a solid base from which we can begin. PMID:17340383

  5. Conscious vision for action versus unconscious vision for action?

    PubMed

    Brogaard, Berit

    2011-08-01

    David Milner and Melvyn Goodale's dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related "unconscious" stream and a ventral, perception-related "conscious" stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division. PMID:21790744

  6. Are Medications Involved in Vision and Intracranial Pressure Changes Seen in Spaceflight?

    NASA Technical Reports Server (NTRS)

    Wotring, V. E.

    2015-01-01

    Some crewmembers have experienced changes in their vision after long-duration spaceflight on the ISS. These impairments include visual performance decrements, development of cotton-wool spots or choroidal folds, optic-disc edema, optic nerve sheath distention, and/or posterior globe flattening with varying degrees of severity and permanence. These changes are now used to define the visual impairment/intracranial pressure (VIIP) syndrome. It is known that many medications can have side effects that are similar to VIIP symptoms. Some medications raise blood pressure, which can affect intracranial pressure. Many medications that act in the central nervous system can affect intracranial pressures and/or vision. About 40% of the medications in the ISS kit are known to cause side effects involving changes in blood pressure, intracranial pressure and/or vision. For this reason, we have begun an investigation of the potential relationship between ISS medications and their risk of causing or exacerbating VIIP-like symptoms.

  7. Neuroimaging of amblyopia and binocular vision: a review

    PubMed Central

    Joly, Olivier; Frankó, Edit

    2014-01-01

    Amblyopia is a cerebral visual impairment considered to derive from abnormal visual experience (e.g., strabismus, anisometropia). Amblyopia, first considered as a monocular disorder, is now often seen as a primarily binocular disorder resulting in more and more studies examining the binocular deficits in the patients. The neural mechanisms of amblyopia are not completely understood even though they have been investigated with electrophysiological recordings in animal models and more recently with neuroimaging techniques in humans. In this review, we summarize the current knowledge about the brain regions that underlie the visual deficits associated with amblyopia with a focus on binocular vision using functional magnetic resonance imaging. The first studies focused on abnormal responses in the primary and secondary visual areas whereas recent evidence shows that there are also deficits at higher levels of the visual pathways within the parieto-occipital and temporal cortices. These higher level areas are part of the cortical network involved in 3D vision from binocular cues. Therefore, reduced responses in these areas could be related to the impaired binocular vision in amblyopic patients. Promising new binocular treatments might at least partially correct the activation in these areas. Future neuroimaging experiments could help to characterize the brain response changes associated with these treatments and help devise them. PMID:25147511

  8. Control of shell colour changes in the lobster, Panulirus cygnus.

    PubMed

    Wade, Nicholas M; Melville-Smith, Roy; Degnan, Bernard M; Hall, Michael R

    2008-05-01

    The transition from juvenile to adult in the Australian western rock lobster, Panulirus cygnus (George), is preceded by a mass migration from inshore nursery reefs to offshore breeding grounds. Associated with this migration is a moult which results in the animals that are due to migrate undergoing characteristic colour change from deep red to pale pink, known as the ;white' phase, which is believed to be triggered by environmental factors. To investigate this phenomenon, the colour change of wild-caught animals was measured over two separate years in response to two important modifiers of crustacean shell colour, dietary carotenoid and background substrate colour. Changes in shell colour during this colour transition period were influenced more greatly by other factors independent of diet or background substrate and no mass colour change was induced during this time. Shell colour measurement and carotenoid quantification confirmed the presence of animals similar to wild-caught ;whites', regardless of the treatment. From these experimental observations we infer that the ;white' phase of the western rock lobster is not triggered by dietary modification or in response to background substrate. We propose that this transition is under the regulation of an ontogenetic program activated at a specific moult, which induces presently unidentified molecular changes linked to shell colour production. This unique colour transition may have evolved to provide protective camouflage during migration, and serves as an excellent model to study the genetic mechanisms underlying crustacean shell colouration. These data also provide insight into the changes in carotenoid levels induced by environmental factors, and the ability to modify crustacean shell colour in aquaculture. PMID:18424686

  9. Ecology of the fruit-colour polymorphism in Rubus spectabilis

    Microsoft Academic Search

    Anna Traveset; Mary F. Willson

    1998-01-01

    Although some studies have focused on the colour polymorphisms of flowers and fruits, little is known of their ecological\\u000a and evolutionary significance. We investigated the potential contribution of several factors to the maintenance of fruit-colour\\u000a polymorphism in Rubus spectabilis, a common shrub in the temperate rainforests of southeast Alaska. Fruits occur in two colours\\u000a (red and orange), whose frequencies vary

  10. Perceptual organization in colour perception: Inverting the gamut expansion effect

    PubMed Central

    Ekroll, Vebjørn; Faul, Franz

    2013-01-01

    In the well-known gamut expansion effect, uniformly coloured target patches are perceived as more colourful when they are embedded in a uniform grey surround than when they are embedded in a variegated one. Here, we provide a demonstration showing that this effect can be inverted when the uniformly coloured target patches are replaced by variegated ones. This observation suggests that the gamut expansion effect is due to mechanisms of transparency perception rather than due to contrast adaptation. PMID:24349691

  11. Colour simplex coding for brillouin distributed sensors

    NASA Astrophysics Data System (ADS)

    Le Floch, Sébastien; Sauser, Florian; Llera, Miguel; Soto, Marcelo A.; Thévenaz, Luc

    2013-05-01

    The possibility to customize Simplex coding for long range Brillouin Optical Time Domain Analysis is demonstrated by "colouring" the sequences in the frequency domain. The coding gain is identical to the traditional intensity-modulated Simplex code, though with much simplified series of sequences. The frequency-hopping pulses in return-to-zero intensity-modulated format are generated with a Direct-Digital Synthesizer. The proof-of-concept is experimentally demonstrated with measurements over a 50 km range (100 km fibre-loop) and a 2 meter spatial resolution.

  12. Automated human vision assessment using computer vision and artificial intelligence

    Microsoft Academic Search

    Jonathan Van Eenwyk; Arvin Agah; Gerhard W. Cibis

    2008-01-01

    This paper presents an automated system to assess human vision to identify early signs of vision disorders such as amblyopia (lazy eye), so that potential problems can be addressed as early as possible by having the system refer children to a specialist (pediatric ophthalmologist). The system does not require extensive operator training or patient cooperation. This paper explores the application

  13. Environmental colour affects aspects of single-species population dynamics.

    PubMed Central

    Petchey, O L

    2000-01-01

    Single-species populations of ciliates (Colpidium and Paramecium) experienced constant temperature or white or reddened temperature fluctuations in aquatic microcosms in order to test three hypotheses about how environmental colour influences population dynamics. (i) Models predict that the colour of population dynamics is tinged by the colour of the environmental variability. However, environmental colour had no effect on the colour of population dynamics. All population dynamics in this experiment were reddened, regardless of environmental colour. (ii) Models predict that populations will track reddened environmental variability more closely than white environmental variability and that populations with a higher intrinsic growth rate (r) will track environmental variability more closely than populations with a low r. The experimental populations behaved as predicted. (iii) Models predict that population variability is determined by interaction between r and the environmental variability. The experimental populations behaved as predicted. These results show that (i) reddened population dynamics may need no special explanation, such as reddened environments, spatial subdivision or interspecific interactions, and (ii) and (iii) that population dynamics are sensitive to environmental colour, in agreement with population models. Correct specification of the colour of the environmental variability in models is required for accurate predictions. Further work is needed to study the effects of environmental colour on communities and ecosystems. PMID:10819142

  14. Development of a forensic skin colour predictive test.

    PubMed

    Maroñas, Olalla; Phillips, Chris; Söchtig, Jens; Gomez-Tato, Antonio; Cruz, Raquel; Alvarez-Dios, José; de Cal, María Casares; Ruiz, Yarimar; Fondevila, Manuel; Carracedo, Ángel; Lareu, María V

    2014-11-01

    There is growing interest in skin colour prediction in the forensic field. However, a lack of consensus approaches for recording skin colour phenotype plus the complicating factors of epistatic effects, environmental influences such as exposure to the sun and unidentified genetic variants, present difficulties for the development of a forensic skin colour predictive test centred on the most strongly associated SNPs. Previous studies have analysed skin colour variation in single unadmixed population groups, including South Asians (Stokowski et al., 2007, Am. J. Hum. Genet, 81: 1119-32) and Europeans (Jacobs et al., 2013, Hum Genet. 132: 147-58). Nevertheless, a major challenge lies in the analysis of skin colour in admixed individuals, where co-ancestry proportions do not necessarily dictate any one person's skin colour. Our study sought to analyse genetic differences between African, European and admixed African-European subjects where direct spectrometric measurements and photographs of skin colour were made in parallel. We identified strong associations to skin colour variation in the subjects studied from a pigmentation SNP discovery panel of 59 markers and developed a forensic online classifier based on naïve Bayes analysis of the SNP profiles made. A skin colour predictive test is described using the ten most strongly associated SNPs in 8 genes linked to skin pigmentation variation. PMID:25082135

  15. Rapidity Gaps in DIS through Soft Colour Interactions

    E-print Network

    A. Edin; G. Ingelman; J. Rathsman

    1995-08-03

    We present a new mechanism for the creation of large rapidity gaps in DIS events at HERA. Soft colour interactions between perturbatively produced partons and colour-charges in the proton remnant, modifies the colour structure for hadronization giving colour singlet systems that are well separated in rapidity. An explicit model is presented that, although the detailed results depend on the initial state parton emission, can describe both the observed rapidity gaps and, in addition, the forward energy flow in an inclusive event sample.

  16. Trainable Mentally Impaired/Severely Multiply Impaired/Autistic Impaired/Severely Mentally Impaired. Product Evaluation Report 1989-1990.

    ERIC Educational Resources Information Center

    Claus, Richard N.; And Others

    The evaluation report describes special education services provided to trainable mentally impaired (TMI), autistic impaired (AI), severely multiply impaired (SXI), and severely mentally impaired (SMI) students at and through the Melvin G. Millet Learning Center (Bridgeport, Michigan). The eight program components are described individually and…

  17. Make the Most of Your Vision

    MedlinePLUS

    ... people with low vision. You’ll need to experiment to see what works best for you. Special ... then you have Low Vision. read more… Sunglasses – Colors For Low Vision Prescription filters are one of ...

  18. Vision, reanimated and reimagined Shimon Edelman

    E-print Network

    Edelman, Shimon

    and artificial intelligence. 1 #12;Meanwhile, the rate of progress in understanding the brain basis of vision of David Marr's Vision has delivered a singular boost and a course correction to the science of vision

  19. Genetics Home Reference: Color vision deficiency

    MedlinePLUS

    ... represents a group of conditions that affect the perception of color. Red-green color vision defects are ... two forms of color vision deficiency disrupt color perception but do not affect the sharpness of vision ( ...

  20. Analysis of organic colouring and binding components in colour layer of art works.

    PubMed

    Kuckova, S; Nemec, I; Hynek, R; Hradilova, J; Grygar, T

    2005-05-01

    Two methods of analysis of organic components of colour layers of art works have been tested: IR microspectroscopy of indigo, Cu-phthalocyanine, and Prussian blue, and MALDI-TOF-MS of proteinaceous binders and a protein-containing red dye. The IR spectra distortion common for smooth outer surfaces and polished cross sections of colour layer of art works is suppressed by reflectance measurement of microtome slices. The detection limit of the three blue pigments examined is approximately 0.3 wt% in reference colour layers in linseed oil binder with calcite as extender and lead white as a drying agent. The sensitivity has been sufficient to identify Prussian blue in repaints on a Gothic painting. MALDI-TOF-MS has been used to identify proteinaceous binders in two historical paintings, namely isinglass (fish glue) and rabbit glue. MALDI-TOF-MS has also been proposed for identification of an insect red dye, cochineal carmine, according to its specific protein component. The enzymatic cleavage with trypsin before MALDI-TOF-MS seems to be a very gentle and specific way of dissolution of the colour layers highly polymerised due to very long aging of old, e.g. medieval, samples. PMID:15800763