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Introduction Colour-impaired vision, where certain colours cannot be  

E-print Network

these colours. Dark green, brown, orange, and dark red in the first row appear as almost indistinguishable olive, where he produces print graphics for daily publication and interactive web graphics. nvkelso

Jenny, Bernhard


Colour, vision and ergonomics.  


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

Pinheiro, Cristina; da Silva, Fernando Moreira



All Vision Impairment  


... 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. ...


Unconventional colour vision.  


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

Marshall, Justin; Arikawa, Kentaro



Polymorphism and Adaptation of Primate Colour Vision  

E-print Network

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

Fedigan, Linda M.


A Colour Vision Experiment.  

ERIC Educational Resources Information Center

The model for color vision put forward by Edwin Land is explained. The aspects of the theory that can be demonstrated within the classroom are described. A random arrangement of straight-edged colored areas mounted on a screen, called a Mondrian, projectors, and a computer are used to calculate reflectance. (KR)

Lovett, David; Hore, Kevin



Kids' Quest: Vision Impairment  


... for this most important job. [ Return to Steps ] World-Wide Web Search Kids Health: What is Vision Impairment What would life be like if you couldn't see a dog wag its tail or watch a ladybug crawl ... 5.000 metres. Runyan's career as a world-class runner began in 1999 at the Pan ...


The handicap of abnormal colour vision.  


All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour. PMID:15312030

Cole, Barry L



Colour vision: parallel pathways intersect in Drosophila.  


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

Kelber, Almut; Henze, Miriam J



Vision Impairment and Blindness  


... be restored. It can, however, be managed. A loss of vision means that you may have to reorganize your life and learn new ways of doing things. If you have some vision, visual aids such as special glasses and large print ...


Vision impairment in Liverpool: prevalence and morbidity  

Microsoft Academic Search

A database related to the activities of the Liverpool vision assessment team was used to identify all children with vision impairment aged 0-16 years, resident in Liverpool, UK, on 1 April 1995. Prevalence rates were calculated for all children with vision impairment, and separately for two groups: those with uncomplicated vision impairment, and those with additional pathology. Visual tract pathologies

M Rogers



Mechanisms, functions and ecology of colour vision in the honeybee.  


Research in the honeybee has laid the foundations for our understanding of insect colour vision. The trichromatic colour vision of honeybees shares fundamental properties with primate and human colour perception, such as colour constancy, colour opponency, segregation of colour and brightness coding. Laborious efforts to reconstruct the colour vision pathway in the honeybee have provided detailed descriptions of neural connectivity and the properties of photoreceptors and interneurons in the optic lobes of the bee brain. The modelling of colour perception advanced with the establishment of colour discrimination models that were based on experimental data, the Colour-Opponent Coding and Receptor Noise-Limited models, which are important tools for the quantitative assessment of bee colour vision and colour-guided behaviours. Major insights into the visual ecology of bees have been gained combining behavioural experiments and quantitative modelling, and asking how bee vision has influenced the evolution of flower colours and patterns. Recently research has focussed on the discrimination and categorisation of coloured patterns, colourful scenes and various other groupings of coloured stimuli, highlighting the bees' behavioural flexibility. The identification of perceptual mechanisms remains of fundamental importance for the interpretation of their learning strategies and performance in diverse experimental tasks. PMID:24828676

Hempel de Ibarra, N; Vorobyev, M; Menzel, R



From spectral information to animal colour vision: experiments and concepts  

PubMed Central

Many animals use the spectral distribution of light to guide behaviour, but whether they have colour vision has been debated for over a century. Our strong subjective experience of colour and the fact that human vision is the paradigm for colour science inevitably raises the question of how we compare with other species. This article outlines four grades of ‘colour vision’ that can be related to the behavioural uses of spectral information, and perhaps to the underlying mechanisms. In the first, even without an (image-forming) eye, simple organisms can compare photoreceptor signals to locate a desired light environment. At the next grade, chromatic mechanisms along with spatial vision guide innate preferences for objects such as food or mates; this is sometimes described as wavelength-specific behaviour. Here, we compare the capabilities of di- and trichromatic vision, and ask why some animals have more than three spectral types of receptors. Behaviours guided by innate preferences are then distinguished from a grade that allows learning, in part because the ability to learn an arbitrary colour is evidence for a neural representation of colour. The fourth grade concerns colour appearance rather than colour difference: for instance, the distinction between hue and saturation, and colour categorization. These higher-level phenomena are essential to human colour perception but poorly known in animals, and we suggest how they can be studied. Finally, we observe that awareness of colour and colour qualia cannot be easily tested in animals. PMID:20164101

Kelber, Almut; Osorio, Daniel



Contrast normalization in colour vision: the effect of luminance contrast on colour contrast detection  

PubMed Central

While contrast normalization is well known to occur in luminance vision between overlaid achromatic contrasts, and in colour vision between overlaid colour contrasts, it is unknown whether it transfers between colour and luminance contrast. Here we investigate whether contrast detection in colour vision can be normalized by achromatic contrast, or whether this is a selective process driven only by colour contrast. We use a method of cross-orientation masking, in which colour detection is masked by cross-oriented achromatic contrast, over a range of spatio-temporal frequencies (0.375–1.5?cpd, 2–8?Hz). We find that there is virtually no cross-masking of colour by achromatic contrast under monocular or binocular conditions for any of the spatio-temporal frequencies tested, although we find significant facilitation at low spatio-temporal conditions (0.375?cpd, 2?Hz). These results indicate that the process of contrast nornalization is colour selective and independent of achromatic contrast, and imply segregated chromatic signals in early visual processing. Under dichoptic conditions, however, we find a strikingly different result with significant masking of colour by achromatic contrast. This indicates that the dichoptic site of suppression is unselective, responding similarly to colour and luminance contrast, and suggests that dichoptic suppression has a different origin from monocular or binocular suppression. PMID:25491564

Mullen, Kathy T.; Kim, Yeon Jin; Gheiratmand, Mina



Colour vision in diurnal and nocturnal hawkmoths.  


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

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



[Inherited colour vision deficiencies--from Dalton to molecular genetics].  


In recent years, great advances have been made in our understanding of the molecular basis of colour vision defects, as well as of the patterns of genetic variation in individuals with normal colour vision. Molecular genetic analyses have explained the diversity of types and degrees of severity in colour vision anomalies, their frequencies, pronounced individual variations in test results, etc. New techniques have even enabled the determination of John Dalton's real colour vision defect, 150 years after his death. Inherited colour vision deficiencies most often result from the mutations of genes that encode cone opsins. Cone opsin genes are linked to chromosomes 7 (the S or "blue" gene) and X (the L or "red" gene and the M or "green" gene). The L and M genes are located on the q arm of the X chromosome in a head-to-tail array, composed of 2 to 6 (typically 3) genes--a single L is followed by one or more M genes. Only the first two genes of the array are expressed and contribute to the colour vision phenotype. The high degree of homology (96%) between the L and M genes predisposes them to unequal recombination, leading to gene deletion or the formation of hybrid genes (comprising portions of both the L and M genes), explaining the majority of the common red-green colour vision deficiencies. The severity of any deficiency is influenced by the difference in spectral sensitivity between the opsins encoded by the first two genes of the array. A rare defect, S monochromacy, is caused either by the deletion of the regulatory region of the array or by mutations that inactivate the L and M genes. Most recent research concerns the molecular basis of complete achromatopsia, a rare disorder that involves the complete loss of all cone function. This is not caused by mutations in opsin genes, but in other genes that encode cone-specific proteins, e.g. channel proteins and transducin. PMID:16758855

Cvetkovi?, Dragana; Cvetkovi?, Dobrosav



Bird colour vision: behavioural thresholds reveal receptor noise.  


Birds have impressive physiological adaptations for colour vision, including tetrachromacy and coloured oil droplets, yet it is not clear exactly how well birds can discriminate the reflecting object colours that they encounter in nature. With behavioural experiments, we determined colour discrimination thresholds of chickens in bright and dim light. We performed the experiments with two colour series, orange and green, covering two parts of chicken colour space. These experiments allowed us to compare behavioural results with model expectations and determine how different noise types limit colour discrimination. At intensities ranging from bright light to those corresponding to early dusk (250-10 cd m(-2)), we describe thresholds accurately by assuming a constant signal-to-noise ratio, in agreement with an invariant Weber fraction of Weber's law. Below this intensity, signal-to-noise ratio decreases and Weber's law is violated because photon-shot noise limits colour discrimination. In very dim light (below 0.05cd m(-2) for the orange series or 0.2 cd m(-2) for the green series) colour discrimination is possibly constrained by dark noise, and the lowest intensity at which chickens can discriminate colours is 0.025 and 0.08 cd m(-2) for the orange and green series, respectively. Our results suggest that chickens use spatial pooling of cone outputs to mitigate photon-shot noise. Surprisingly, we found no difference between colour discrimination of chickens and humans tested with the same test in bright light. PMID:25609782

Olsson, Peter; Lind, Olle; Kelber, Almut





We have proposed a novel concept of vision multiplexing for the visually impaired - superimposing contour images over their natural view of a scene or over original images presented on a TV screen. We have implemented the concept using an optical see-through head mounted display to provide either visual field expansion to patients with peripheral field loss or vision enhancement to patients with central vision loss. We have also implemented the concept in a video player with dynamic magnification for patients with central vision loss. Results of initial testing in the lab and on the street are promising. PMID:20161449

Peli, Eli; Luo, Gang; Bowers, Alex; Rensing, Noa



Ultraviolet sensitivity and colour vision in raptor foraging.  


Raptors have excellent vision, yet it is unclear how they use colour information. It has been suggested that raptors use ultraviolet (UV) reflections from vole urine to find good hunting grounds. In contrast, UV plumage colours in songbirds such as blue tits are assumed to be 'hidden' communication signals, inconspicuous to raptors. This ambiguity results from a lack of knowledge about raptor ocular media transmittance, which sets the limit for UV sensitivity. We measured ocular media transmittance in common buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), red kites (Milvus milvus) and kestrels (Falco tinnunculus) so that, for the first time, raptor UV sensitivity can be fully described. With this information, and new measurements of vole urine reflectance, we show that (i) vole urine is unlikely to provide a reliable visual signal to hunting raptors and (ii) blue tit plumage colours are more contrasting to blue tits than to sparrowhawks because of UV reflectance. However, as the difference between blue tit and sparrowhawk vision is subtle, we suggest that behavioural data are needed to fully resolve this issue. UV cues are of little or no importance to raptors in both vole and songbird interactions and the role of colour vision in raptor foraging remains unclear. PMID:23785106

Lind, Olle; Mitkus, Mindaugas; Olsson, Peter; Kelber, Almut



Evaluating and Stimulating Vision in the Multiply Impaired.  

ERIC Educational Resources Information Center

Techniques for evaluating the multiply impaired child's functional level of vision are described and a sequence of visual stimulation instruction for children with visual impairments is presented. (PHR)

Jose, Randall T.; And Others



Psychological Adjustment in Adolescents with Vision Impairment  

ERIC Educational Resources Information Center

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…

Pinquart, Martin; Pfeiffer, Jens P.



Origins of colour vision standards within the transport industry.  


Colour vision standards should reflect changes in our understanding of the nature of these defects as well as technological advances that place less importance upon the visual senses of the human operator. Therefore it is suggested that visual standards be subject to routine reviews in order to assess their suitability for modern work environments. This paper gives a chronological account of the introduction of colour vision standards by several national transport authorities and identifies historical reasons that led to their implementation. It is concluded that the same factors that gave rise to the adoption of early colour vision standards are still relevant for modern transport systems. However the recent deployment of automatic or semi-automatic control or navigational systems has substantially altered man's role from being the primary source of information input to one of a monitoring process. This has generated a good deal of debate and uncertainty regarding the level of responsibility that a human operator has for the control of modern transport vehicles. Nevertheless, it is argued that in the absence of complete automation some type of visual standard is needed whenever visual judgements must be made by human observers. PMID:3306566

Vingrys, A J; Cole, B L



Avian retinal oil droplets: dietary manipulation of colour vision?  

PubMed Central

Avian vision is highly developed, with bird retinas containing rod and double-cone photoreceptors, plus four classes of single cones subserving tetrachromatic colour vision. Cones contain an oil droplet, rich in carotenoid pigments (except VS/ultraviolet-sensitive cones), that acts as a filter, substantially modifying light detected by the photoreceptor. Using dietary manipulations, we tested the effects of carotenoid availability on oil droplet absorbance properties in two species: Platycercus elegans and Taeniopygia guttata. Using microspectrophotometry, we determined whether manipulations affected oil droplet carotenoid concentration and whether changes would alter colour discrimination ability. In both species, increases in carotenoid concentration were found in carotenoid-supplemented birds, but only in the double cones. Magnitudes of effects of manipulations were often dependent on retinal location. The study provides, to our knowledge, the first experimental evidence of dietary intake over a short time period affecting carotenoid concentration of retinal oil droplets. Moreover, the allocation of carotenoids to the retina by both species is such that the change potentially preserves the spectral tuning of colour vision. Our study generates new insights into retinal regulation of carotenoid concentration of oil droplets, an area about which very little is known, with implications for our understanding of trade-offs in carotenoid allocation in birds. PMID:19939843

Knott, Ben; Berg, Mathew L.; Morgan, Eric R.; Buchanan, Katherine L.; Bowmaker, James K.; Bennett, Andrew T. D.



Theory and practice of colour vision testing: A review Part 1  

PubMed Central

Lakowski, R. (1969).Brit. J. industr. Med.,26, 173-189. Theory and practice of colour vision testing: A review Part I. It is the concern of this paper to examine not only the effectiveness of tests for detecting colour confusion but also their usefulness in assessing colour vision generally. In part 1, problems of administration and age and the question of the basic elements of such tests are discussed. The existing theory of colour vision and colour defect is outlined and the principle of objective colour specification, which is believed to be valuable for understanding these tests, is introduced. PMID:4893872

Lakowski, R.



Robot Vision for the Visually Impaired  

Microsoft Academic Search

We present a head-mounted, stereo-vision based navigational assistance device for the visually impaired. The head-mounted design enables our subjects to stand and scan the scene for integrating wide-field information, compared to shoulder or waist-mounted designs in literature which require body rotations. In order to extract and maintain orientation information for creating a sense of egocentricity in blind users, we incorporate

Vivek Pradeep; Gerard Medioni; James Weiland



Orientation tuning in human colour vision at detection threshold  

PubMed Central

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

Gheiratmand, Mina; Mullen, Kathy T.



Adaptive plasticity during the development of colour vision.  


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 spectral sensitivity of visual pigments and the ratio of spectral cone types are also variable. This results in a situation where there is no fixed relationship between a stimulus and a colour percept. Colour constancy has been identified as a powerful mechanism to deal with this set of problems; however, it is active only in a short-term time range. Changes covering longer periods of time require additional tuning mechanisms at the photoreceptor level or at postreceptoral stages of chromatic processing. We have used the trichromatic blue acara (Aequidens pulcher, Cichlidae) as a model system and studied retinal morphology and physiology, and visually evoked behaviour after rearing fish for 1-2 years under various conditions including near monochromatic lights (spectral deprivation) and two intensities of white light (controls). In general, long-term exposure to long wavelengths light had lesser effects than light of middle and short wavelengths. Within the cone photoreceptors, spectral deprivation did not change the absorption characteristics of the visual pigments. By contrast, the outer segment length of middle and long-wave-sensitive cones was markedly increased in the blue rearing group. Furthermore, in the same group, we observed a loss of 65% short-wave-sensitive cones after 2 years. These changes may be interpreted as manifestations of compensatory mechanisms aimed at restoring the balance between the chromatic channels. At the horizontal cell level, the connectivity between short-wave-sensitive cones and the H2 cone horizontal cells, and the spinule dynamics were both affected in the blue light group. This observation rules out the role of spinules as sites of chromatic feedback synapses. The light-evoked responses of H2 horizontal cells were also sensitive to spectral deprivation showing a shift of the neutral point towards short wavelengths in the blue rearing group. Interestingly, we also found an intensity effect because in the group reared in bright white light the neutral point was more towards longer wavelength than in the dim light group. Like the changes in the cones, the reactions of horizontal cells to spectral deprivation in the long wave domain can be characterised as compensatory. We also tested the spectral sensitivity of the various experimental groups of blue acara in visually evoked behaviour using the optomotor response paradigm. In this case, the changes in the relative spectral sensitivity were more complex and could not be explained by a simple extrapolation of the adaptive and compensatory processes in the outer retina. We conclude that the inner retina, and/or the optic tectum are also involved and react to the changes of the spectral environment. In summary, we have shown a considerable developmental plasticity in the colour vision system of the blue acara, where epigenetic adaptive processes at various levels of the visual system respond to the specific spectral composition of the surroundings and provide a powerful mechanism to ensure functional colour vision in different visual environments. We suggest that processes involving an active fine-tuning of the photoreceptors and the postreceptoral processing of chromatic information during ontogenetic development are a general feature of all colour vision systems. Such mechanisms would establish a functional balance between the various chromatic channels. This appears to be an essential condition for the cognitive systems to extract the relevant and stable information from the unstable and changing stimulus situation. PMID:15845347

Wagner, Hans-Joachim; Kröger, Ronald H H



Stochastic spineless expression creates the retinal mosaic for colour vision.  


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

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



Is screening for congenital colour vision deficiency in school students worthwhile? A review.  


This review analyses the literature on screening for congenital colour vision deficiency in school students, which predominantly uses the Ishihara test. The review was framed with respect to the established Wilson and Jungner criteria for screening programs. These criteria relate to the characteristics of the condition concerned, the performance of the screening test, the existence of treatment options and the performance of screening programs. The literature reviewed suggests that congenital colour vision deficiency has not been shown to increase risk of road traffic crashes and is not a preclusion to driver licensing in most developed countries. The occurrence of congenital colour vision deficiency has been used to limit entry into certain occupations; however, the value of screening school students with regard to occupational preclusion is questionable. Stronger evidence exists indicating no association between congenital colour vision deficiency and level of educational achievement. Studies showing any association between congenital colour vision deficiency and other health and lifestyle impacts were rare. The most commonly used screening test (using Ishihara pseudoisochromatic plates) performs well with respect to detecting red-green colour vision deficiencies. Finally, the only interventions we identified for congenital colour vision deficiency were management ones around the availability of specific tinted lenses and computer programs to aid colour perception in certain tasks. Given this picture, the weight of evidence appears to be in favour of not adopting (or discontinuing) routine colour vision screening programs for school students; however, it may be worthwhile for a career advisor to refer school students to an optometrist or ophthalmologist for colour vision screening, upon expression of interest in an occupation where normal colour vision is either particularly desirable or is a regulatory requirement. PMID:25039829

Ramachandran, Nishanthan; Wilson, Graham A; Wilson, Nick



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

ERIC Educational Resources Information Center

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…

Torrents, Aurora; Bofill, Francesc; Cardona, Genis



The fiddler crab Uca mjoebergi uses colour vision in mate choice  

PubMed Central

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

Detto, Tanya



Vibrotactile colour rendering for the visually impaired within the VIDET project  

E-print Network

Vibrotactile colour rendering for the visually impaired within the VIDET project Luca Cappelletti for the visually impaired. An important enhancement would be colour rendering. Here we face the possibility. INTRODUCTION VIDET (VIsual DEcoder by Touch) will be a portable device by which a visually impaired person

Ferri, Massimo


Research the mobile phone operation interfaces for vision-impairment.  


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

Yao, Yen-Ting; Leung, Cherng-Yee



Correlations between the neurobiology of colour vision and the psycholinguistics of colour naming  

Microsoft Academic Search

Summary Neurobiological experiments demonstrate that colour sensation is perceived by the brain by processes which, in principle, follow the opponent colour pairs scheme proposed by Hering in 1874. Tests on colour naming in various European, Asian and Central American languages have shown that the opponent scheme is also reflected in psycholinguistics. The linguistic evolution of colour terms proposed by Berlin

Heinrich Zollinger; Roman Jakobson



The ChromaGen contact lens system: colour vision test results and subjective responses.  


The ChromaGen lens system is designed to enhance colour perception in colour vision deficiency (CVD). To investigate its efficacy, 14 CVD subjects were prescribed ChromaGen contact lenses. Colour vision tests (Ishihara, Farnsworth Munsell D-15, Farnsworth Lantern) were administered at baseline, lens dispensing, and after a 2-week lens-wearing trial during which subjective responses were recorded daily using visual analogue scales. ChromaGen lenses significantly reduced ishihara error rates (p < 0.001; ANOVA), particularly for deutan subjects. There was also a significant reduction in errors (p < 0.005) on the D-15 test. Conversely, lens wear had no significant effect on Farnsworth Lantern test performance. Subjectively, subjects reported enhanced colour perception, but poor vision in dim light. Judgement of distance and motion were only slightly affected. We conclude that ChromaGen lenses may enhance subjective colour experience and assist in certain colour-related tasks, but are not indicated as an aid for CVD in occupations with colour vision-related restrictions. PMID:11396392

Swarbrick, H A; Nguyen, P; Nguyen, T; Pham, P



Vision impairment in the Pacific region  

PubMed Central

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

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



A Modified Pseudoisochromatic Ishihara Colour Vision Test Based on Eastern Arabic Numerals  

PubMed Central

Congenital colour vision defects affect about 8% and 0.5% of the male and female population, respectively. Pseudoisochromatic Ishihara plates have shown to be successful in an early diagnosis of colour vision defects. This commonly used colour vision test was initially intended to identify those who suffered from red-green aspect of congenital colour blindness; however, it may be of use to reveal acquired colour vision defects as well. Despite the Ishihara plates’ value, there are a number of shortcomings in their current layout. We proposing a new colour plate modified from original Ishihara test. To best assist illiterates who are not able to read English, standard Ishihara plates have been translated to Eastern Arabic numerals, which are used in most parts of the Middle East, Central Asia and Africa populations. The purpose of the present modification was to present the new plates to these regions, but more research and study is required to work on the validity, reliability, and repeatability of these new plates. PMID:24600648

Heidary, Fatemeh; Gharebaghi, Reza



Global cost of correcting vision impairment from uncorrected refractive error  

PubMed Central

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

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



Sensory impairment in older adults: part 2: Vision loss.  


A decline in vision occurs naturally with age; more severe impairment can result from medical conditions such as age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy. Nurses can pick up signs of visual impairment and suggest certain environmental modifications to prevent injury, such as keeping floors free of clutter and rooms well lit. Although assistive technologies such as optical devices, magnifiers, telescopes, and electronic magnification can help, some forms of impairment, such as that caused by cataracts and uncorrected refractive error, can be corrected. PMID:17068436

Whiteside, Meredith M; Wallhagen, Margaret I; Pettengill, Elaine



Eye development: stable cell fate decisions in insect colour vision.  


The retina provides an example of a fundamental property of developing cells: cell fate decisions are stable. A recent paper reports a double negative feedback loop that leads to bistable fate decisions in the colour-detecting photoreceptors of Drosophila. PMID:16303550

Freeman, Matthew



Colour vision in ADHD: Part 1 -Testing the retinal dopaminergic hypothesis  

E-print Network

Colour vision in ADHD: Part 1 - Testing the retinal dopaminergic hypothesis Soyeon Kim1 Email Objectives To test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD with ADHD and 30 healthy young adults, matched on age and gender, performed a psychophysical task to measure

Carrasco, Marisa


Visual search performance of patients with vision impairment: effect of JPEG image enhancement  

E-print Network

Visual search performance of patients with vision impairment: effect of JPEG image enhancement Gang & Peli E. Visual search performance of patients with vision impairment: effect of JPEG image enhancement option for patients with vision impairment resulting from loss of visual acuity and or contrast

Peli, Eli


Vision impairment predicts 5 year mortality  

PubMed Central

AIM—To describe predictors of mortality in the 5 year follow up of the Melbourne Visual Impairment Project (VIP) cohort.?METHODS—The Melbourne VIP was a population based study of the distribution and determinants of age related eye disease in a cluster random sample of Melbourne residents aged 40 years and older. Baseline examinations were conducted between 1992 and 1994. In 1997, 5 year follow up examinations of the original cohort commenced. Causes of death were obtained from the National Death Index for all reported deaths.?RESULTS—Of the original 3271 participants, 231 (7.1%) were reported to have died in the intervening 5 years. Of the remaining 3040 participants eligible to return for follow up examinations, 2594 (85% of eligible) did participate, 51 (2%) had moved interstate or overseas, 83 (3%) could not be traced, and 312 (10%) refused to participate. Best corrected visual acuity <6/12 (OR=2.34) was associated with a significantly increased risk of mortality, as were increasing age (OR=1.09), male sex (OR=1.62), increased duration of cigarette smoking (OR=2.06 for smoking >30 years), increased duration of hypertension (OR=1.51 for duration >10 years), and arthritis (OR=1.42).?CONCLUSIONS—Even mild visual impairment increases the risk of death more than twofold. Further research is needed to determine why decreased visual acuity is associated with increased risk of mortality.?? PMID:11222339

McCarty, C.; Nanjan, M.; Taylor, H.



The nature of sound and vision in relation to colour  

NASA Astrophysics Data System (ADS)

The increasing role of sound within the visual arts context and the trend in postmodernism towards interdisciplinary artworks has demanded a heightened awareness of the audio-visual. This paper explores some of the fundamental physical properties of both sound and colour, their similarities and differences and how the audio and visual senses are related. Ways in which soundscapes have been combined with paintings in exhibitions by the author will be used to illustrate how the two media can be combined to enhance the overall artistic experience.

Greated, Marianne



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

PubMed Central

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

Lakowski, R.



Dichromatic Colour Vision in Wallabies as Characterised by Three Behavioural Paradigms  

PubMed Central

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

Ebeling, Wiebke; Hemmi, Jan M.



Mineralized rods and cones suggest colour vision in a 300?Myr-old fossil fish.  


Vision, which consists of an optical system, receptors and image-processing capacity, has existed for at least 520?Myr. Except for the optical system, as in the calcified lenses of trilobite and ostracod arthropods, other parts of the visual system are not usually preserved in the fossil record, because the soft tissue of the eye and the brain decay rapidly after death, such as within 64 days and 11 days, respectively. The Upper Carboniferous Hamilton Formation (300?Myr) in Kansas, USA, yields exceptionally well-preserved animal fossils in an estuarine depositional setting. Here we show that the original colour, shape and putative presence of eumelanin have been preserved in the acanthodii fish Acanthodes bridgei. We also report on the tissues of its eye, which provides the first record of mineralized rods and cones in a fossil and indicates that this 300?Myr-old fish likely possessed colour vision. PMID:25536302

Tanaka, Gengo; Parker, Andrew R; Hasegawa, Yoshikazu; Siveter, David J; Yamamoto, Ryoichi; Miyashita, Kiyoshi; Takahashi, Yuichi; Ito, Shosuke; Wakamatsu, Kazumasa; Mukuda, Takao; Matsuura, Marie; Tomikawa, Ko; Furutani, Masumi; Suzuki, Kayo; Maeda, Haruyoshi



Advanced IT Education for the Vision Impaired via e-Learning  

ERIC Educational Resources Information Center

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…

Armstrong, Helen L.



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

ERIC Educational Resources Information Center

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…

Newcomb, Sandra



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


... 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 ? 40 142,648, ...


Exercise and Drinking May Play a Role in Vision Impairment Risk  


... Exercise and Drinking May Play a Role in Vision Impairment Risk Tweet Eye Health Lifestyle Topics Preventing ... when the signs of disease and changes in vision may start to occur. Follow Us In 2020, ...


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

PubMed Central

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

Osorio, D; Vorobyev, M



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

ERIC Educational Resources Information Center

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…

Thurston, Allen



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

ERIC Educational Resources Information Center

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…

Papadopoulos, Konstantinos; Koustriava, Eleni; Kartasidou, Lefkothea



Television, computer and portable display device use by people with central vision impairment  

E-print Network

Television, computer and portable display device use by people with central vision impairment, USA Citation information: Woods RL & Satgunam P. Television, computer and portable display device use by people with central vision impairment. Ophthalmic Physiol Opt 2011, 31, 258­274. doi: 10.1111/j.1475

Peli, Eli


14 CFR 382.119 - What information must carriers give individuals with vision or hearing impairment on aircraft?  

Code of Federal Regulations, 2011 CFR

...false What information must carriers give individuals with vision or hearing impairment on aircraft? 382.119 Section 382...119 What information must carriers give individuals with vision or hearing impairment on aircraft? (a) As a...



14 CFR 382.53 - What information must carriers give individuals with a vision or hearing impairment at airports?  

Code of Federal Regulations, 2013 CFR

...false What information must carriers give individuals with a vision or hearing impairment at airports? 382.53 Section 382...53 What information must carriers give individuals with a vision or hearing impairment at airports? (a)(1)...



Vision of the active limb impairs bimanual motor tracking in young and older adults  

PubMed Central

Despite the intensive investigation of bimanual coordination, it remains unclear how directing vision toward either limb influences performance, and whether this influence is affected by age. To examine these questions, we assessed the performance of young and older adults on a bimanual tracking task in which they matched motor-driven movements of their right hand (passive limb) with their left hand (active limb) according to in-phase and anti-phase patterns. Performance in six visual conditions involving central vision, and/or peripheral vision of the active and/or passive limb was compared to performance in a no vision condition. Results indicated that directing central vision to the active limb consistently impaired performance, with higher impairment in older than young adults. Conversely, directing central vision to the passive limb improved performance in young adults, but less consistently in older adults. In conditions involving central vision of one limb and peripheral vision of the other limb, similar effects were found to those for conditions involving central vision of one limb only. Peripheral vision alone resulted in similar or impaired performance compared to the no vision (NV) condition. These results indicate that the locus of visual attention is critical for bimanual motor control in young and older adults, with older adults being either more impaired or less able to benefit from a given visual condition. PMID:25452727

Boisgontier, Matthieu P.; Van Halewyck, Florian; Corporaal, Sharissa H. A.; Willacker, Lina; Van Den Bergh, Veerle; Beets, Iseult A. M.; Levin, Oron; Swinnen, Stephan P.




Microsoft Academic Search

In France, some new regulations have been published on December 2006 and January 2007 in order to make the built environment to people with all kinds of impairments and reduced mobility at large. Whereas provisions for ambulant impaired persons and wheelchair users are quite well known, those for vision impaired persons are missing. The Certu, a technical centre of the

Maryvonne Dejeammes; Cyril Chain



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


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

Mogol, Burçe Ataç; Gökmen, Vural



The effect of colour vision status on the detection and selection of fruits by tamarins (Saguinus spp.)  

Microsoft Academic Search

The evolution of trichromatic colour vision by the majority of anthropoid primates has been linked to the efficient detection and selection of food, particularly ripe fruits among leaves in dappled light. Modelling of visual signals has shown that trichromats should be more efficient than dichromats at distinguishing both fruits from leaves and ripe from unripe fruits. This prediction is tested

Andrew C. Smith; Hannah M. Buchanan-Smith; Alison K. Surridge; Daniel Osorio; Nicholas I. Mundy



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

Microsoft Academic Search

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

Helen Armstrong; Iain Murray



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

ERIC Educational Resources Information Center

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…

Hadidi, Muna S. Z.



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

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…

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



A stereo vision-based aid for the visually impaired  

Microsoft Academic Search

This paper describes a portable vision-based obstacle detection system, intended for use by blind people. The system combines an obstacle detection system designed for AGVs with recalibration of ground position and a Kalman Filter based model of the person's walking movement. The system uses stereo vision. Obstacle detection is achieved through comparison of the disparity seen with that expected from

Nicholas Molton; Stephen Se; Michael Brady; David Lee; Penny Probert



Visual Impairment Secondary to Congenital Glaucoma in Children: Visual Responses, Optical Correction and Use of Low Vision Aids  

PubMed Central

INTRODUCTION Congenital glaucoma is frequently associated with visual impairment due to optic nerve damage, corneal opacities, cataracts and amblyopia. Poor vision in childhood is related to global developmental problems, and referral to vision habilitation/rehabilitation services should be without delay to promote efficient management of the impaired vision. OBJECTIVE To analyze data concerning visual response, the use of optical correction and prescribed low vision aids in a population of children with congenital glaucoma. METHOD The authors analyzed data from 100 children with congenital glaucoma to assess best corrected visual acuity, prescribed optical correction and low vision aids. RESULTS Fifty-five percent of the sample were male, 43% female. The mean age was 6.3 years. Two percent presented normal visual acuity levels, 29% mild visual impairment, 28% moderate visual impairment, 15% severe visual impairment, 11% profound visual impairment, and 15% near blindness. Sixty-eight percent received optical correction for refractive errors. Optical low vision aids were adopted for distance vision in 34% of the patients and for near vision in 6%. A manual monocular telescopic system with 2.8 × magnification was the most frequently prescribed low vision aid for distance, and for near vision a +38 diopter illuminated stand magnifier was most frequently prescribed. DISCUSSION AND CONCLUSION Careful low vision assessment and the appropriate prescription of optical corrections and low vision aids are mandatory in children with congenital glaucoma, since this will assist their global development, improving efficiency in daily life activities and promoting social and educational inclusion. PMID:19690654

Haddad, Maria Aparecida Onuki; Sampaio, Marcos Wilson; Oltrogge, Ernst Werner; Kara-José, Newton; Betinjane, Alberto Jorge



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

PubMed Central

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

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



Optic aphasia for colours and colour agnosia: A distinction between visual and visuo-verbal impairments in the processing of colours  

Microsoft Academic Search

Two patients, both of whom would have been described according to classic criteria as cases of colour agnosia, were studied. Three kinds of colour tasks were administered: Visual, verbal and visuo-verbal tasks. However this was not only done by manipulating the kind of stimulus and the kind of response—one being visual, the other verbal (Experiment 1)—as is standard in most

Marie-France Beauvois; Brigitte Saillant



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

ERIC Educational Resources Information Center

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…

Theodorou, Nana; Shipman, Tracey



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

ERIC Educational Resources Information Center

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…

Datta, Poulomee



Students with Low Vision Describe Their Visual Impairments and Visual Functioning  

ERIC Educational Resources Information Center

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…

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



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

PubMed Central

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

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



Space Vision: Making Astronomy Accessible to Visually Impaired Students  

NASA Astrophysics Data System (ADS)

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.

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



Is colour cognitive?  

NASA Astrophysics Data System (ADS)

In recent years, colour-vision abilities have been rather generously ascribed to various invertebrates and even bacteria. This uncertainty of when to diagnose colour vision stems in part from confusing what colour vision can do with what it is. What colour vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a similar confusion of what are necessary and what are sufficient mechanisms and behavioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes—in contrast to the sensation that we have when viewing monochrome movies, or our experience in dim light when only rod vision is possible. The necessary basic equipment for this is to have at least two types of photoreceptors that differ in spectral sensitivity, and at least one type of spectrally opponent cell to compare the signals from the photoreceptors. Clearly, however, a necessary additional prerequisite for colour vision is to have vision, which entails the identification of shapes, sizes and locations of objects in the world. Thus, if an animal has colour vision, it should see an image in which distinct objects/lights have colour attributes. This distinguishes colour vision from wavelength discrimination, but also from what has historically been called wavelength-specific behaviour: a type of behaviour triggered by fixed configurations of spectral receptor signals; however, we discuss difficulties in diagnosing wavelength-specific behaviour as an indicator of the absence of colour vision. Finally, we discuss whether colour vision, by definition, contains a cognitive dimension for ordering and classifying perceptual experience.

Skorupski, Peter; Chittka, Lars



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

ERIC Educational Resources Information Center

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…

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



Effects of peripheral and central vision impairment on mental imagery capacity. 1 Dulin, Hatwell, Pylyshyn, and Chokron  

E-print Network

, Pylyshyn, and Chokron Effects of peripheral and central visual impairment on mental imagery capacity David hypothesized. Impairments seen on mental imagery tasks among brain-damaged patients with visual and/or spatialEffects of peripheral and central vision impairment on mental imagery capacity. 1 Dulin, Hatwell

Pylyshyn, Zenon


Colour Perception in ADHD  

ERIC Educational Resources Information Center

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…

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



Colour vision in the glow-worm Lampyris noctiluca (L.) (Coleoptera: Lampyridae): evidence for a green-blue chromatic mechanism.  


Male glow-worms Lampyris noctiluca find their bioluminescent mates at night by phototaxis. There is good evidence that location of mates by lampyrid beetles is achieved by a single spectral class of photoreceptor, whose spectral sensitivity is tuned to the bioluminescent spectrum emitted by conspecifics, and is achromatic. We ask whether glow-worm phototaxis involves interactions between two spectral classes of photoreceptor. Binary choice experiments were conducted in which males were presented with artificial light stimuli that differ in spectral composition. The normal preference for a green stimulus (lambdamax=555 nm), corresponding to the bioluminescence wavelength produced by signalling females, was significantly reduced by adding a blue (lambdamax=485 nm) component to the signal. This implies an antagonistic interaction between long- and short-wavelength sensitive photoreceptors, suggesting colour vision based on chromatic opponency. Cryosections showed a band of yellow filter pigment in the fronto-dorsal region of the male compound eye, which could severely constrain colour vision in the dim conditions in which the insects signal. This apparent paradox is discussed in the context of the distribution of the pigment within the eye and the photic niche of the species. PMID:15184509

Booth, David; Stewart, Alan J A; Osorio, Daniel



Parallel evolution of angiosperm colour signals: common evolutionary pressures linked to hymenopteran vision  

PubMed Central

Flowering plants in Australia have been geographically isolated for more than 34 million years. In the Northern Hemisphere, previous work has revealed a close fit between the optimal discrimination capabilities of hymenopteran pollinators and the flower colours that have most frequently evolved. We collected spectral data from 111 Australian native flowers and tested signal appearance considering the colour discrimination capabilities of potentially important pollinators. The highest frequency of flower reflectance curves is consistent with data reported for the Northern Hemisphere. The subsequent mapping of Australian flower reflectances into a bee colour space reveals a very similar distribution of flower colour evolution to the Northern Hemisphere. Thus, flowering plants in Australia are likely to have independently evolved spectral signals that maximize colour discrimination by hymenoptera. Moreover, we found that the degree of variability in flower coloration for particular angiosperm species matched the range of reflectance colours that can only be discriminated by bees that have experienced differential conditioning. This observation suggests a requirement for plasticity in the nervous systems of pollinators to allow generalization of flowers of the same species while overcoming the possible presence of non-rewarding flower mimics. PMID:22673351

Dyer, Adrian G.; Boyd-Gerny, Skye; McLoughlin, Stephen; Rosa, Marcello G. P.; Simonov, Vera; Wong, Bob B. M.



Autonomic and Respiratory Measures in Children with Impaired Vision Following Yoga and Physical Activity Programs  

Microsoft Academic Search

We conducted assessments of 28 children with impaired vision (VI group), with ages ranging from 12 to 17 years, and an equal number of age-matched, normal-sighted children (NS group). The VI group had significantly higher rates of breathing, heart rates, and diastolic blood pressure values compared to the NS group (Mann–Whitney U test). Twenty-four of the VI group formed pairs

Shirley Telles; Rajesh B. Srinivas



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

ERIC Educational Resources Information Center

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…

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



Vision Impairment  


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

NASA Astrophysics Data System (ADS)

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.

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



Prevalence of vision impairment and refractive error in school children in Ba Ria – Vung Tau province, Vietnam  

PubMed Central

Background To assess the prevalence of vision impairment and refractive error in school children 12–15 years of age in Ba Ria – Vung Tau province, Vietnam. Design Prospective, cross-sectional study. Participants 2238 secondary school children. Methods Subjects were selected based on stratified multistage cluster sampling of 13 secondary schools from urban, rural and semi-urban areas. The examination included visual acuity measurements, ocular motility evaluation, cycloplegic autorefraction, and examination of the external eye, anterior segment, media and fundus. Main Outcome Measures Visual acuity and principal cause of vision impairment. Results The prevalence of uncorrected and presenting visual acuity ?6/12 in the better eye were 19.4% (95% confidence interval, 12.5–26.3) and 12.2% (95% confidence interval, 8.8–15.6), respectively. Refractive error was the cause of vision impairment in 92.7%, amblyopia in 2.2%, cataract in 0.7%, retinal disorders in 0.4%, other causes in 1.5% and unexplained causes in the remaining 2.6%. The prevalence of vision impairment due to myopia in either eye (–0.50 diopter or greater) was 20.4% (95% confidence interval, 12.8–28.0), hyperopia (?2.00 D) was 0.4% (95% confidence interval, 0.0–0.7) and emmetropia with astigmatism (?0.75 D) was 0.7% (95% confidence interval, 0.2–1.2). Vision impairment due to myopia was associated with higher school grade and increased time spent reading and working on a computer. Conclusions Uncorrected refractive error, particularly myopia, among secondary school children in Vietnam is a major public health problem. School-based eye health initiative such as refractive error screening is warranted to reduce vision impairment. PMID:24299145

Paudel, Prakash; Ramson, Prasidh; Naduvilath, Thomas; Wilson, David; Phuong, Ha Thanh; Ho, Suit M; Giap, Nguyen V



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


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

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



Book4All: A Tool to Make an e-Book More Accessible to Students with Vision\\/Visual-Impairments  

Microsoft Academic Search

Empowering people who are blind or otherwise visually impaired includes ensuring that products and electronic materials incorporate\\u000a a broad range of accessibility features and work well with screen readers and other assistive technology devices. This is\\u000a particularly important for students with vision impairments. Unfortunately, authors and publishers often do not include specific\\u000a criteria when preparing the contents. Consequently, e-books can

Antonello Calabrò; Elia Contini; Barbara Leporini



In-home monitoring of older adults with vision impairment: exploring patients’, caregivers’ and professionals’ views  

PubMed Central

Objective To develop a conceptual framework for the design of an in-home monitoring system (IMS) based on the requirements of older adults with vision impairment (VI), informal caregivers and eye-care rehabilitation professionals. Materials and Methods Concept mapping, a mixed-methods statistical research tool, was used in the construction of the framework. Overall, 40 participants brainstormed or sorted and rated 83 statements concerning an IMS for older adults with VI. Multidimensional scaling and hierarchical cluster analysis were employed to construct the framework. A questionnaire yielded further insights into the views of a wider sample of older adults with VI (n=78) and caregivers (n=25) regarding IMS. Results Concept mapping revealed a nine-cluster model of IMS-related aspects including affordability, awareness of system capabilities, simplicity of installation, operation and maintenance, system integrity and reliability, fall detection and safe movement, user customization, user preferences regarding information delivery, and safety alerts for patients and caregivers. From the questionnaire, independence, safety and fall detection were the most commonly reported reasons for older adults and caregivers to accept an IMS. Concerns included cost, privacy, security of the information obtained through monitoring, system accuracy, and ease of use. Discussion Older adults with VI, caregivers and professionals are receptive to in-home monitoring, mainly for fall detection and safety monitoring, but have concerns that must be addressed when developing an IMS. Conclusion Our study provides a novel conceptual framework for the design of an IMS that will be maximally acceptable and beneficial to our ageing and vision-impaired population. PMID:23676244

Larizza, Melanie Frances; Zukerman, Ingrid; Bohnert, Fabian; Busija, Lucy; Bentley, Sharon Ann; Russell, R Andrew; Rees, Gwyneth



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

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

Abu Bakar, Nurul Farhana; Chen, Ai-Hong



Book4All: A Tool to Make an e-Book More Accessible to Students with Vision/Visual-Impairments  

NASA Astrophysics Data System (ADS)

Empowering people who are blind or otherwise visually impaired includes ensuring that products and electronic materials incorporate a broad range of accessibility features and work well with screen readers and other assistive technology devices. This is particularly important for students with vision impairments. Unfortunately, authors and publishers often do not include specific criteria when preparing the contents. Consequently, e-books can be inadequate for blind and low vision users, especially for students. In this paper we describe a semi-automatic tool developed to support operators who adapt e-documents for visually impaired students. The proposed tool can be used to convert a PDF e-book into a more suitable accessible and usable format readable on desktop computer or on mobile devices.

Calabrò, Antonello; Contini, Elia; Leporini, Barbara


The effects of supplementation with lutein and\\/or zeaxanthin on human macular pigment density and colour vision  

Microsoft Academic Search

Background: Both yellow-blue (YB) discrimination thresholds and macular pigment optical density (MPOD) measurements in the eye exhibit large variability in the normal population. Although it is well established that selective absorption of blue light by the macular pigment (MP) can significantly affect trichromatic colour matches, the extent to which the MP affects colour discrimination (CD) sensitivity remains controversial. Objective: In

Marisa Rodriguez-Carmona; Jessica Kvansakul; J Alister Harlow; Wolfgang Kopcke; Wolfgang Schalch; John L Barbur



Coloured oil droplets enhance colour discrimination.  


The eyes of most diurnal reptiles and birds contain coloured retinal filters-oil droplets. Although these filters are widespread, their adaptive advantage remains uncertain. To understand why coloured oil droplets appeared and were retained during evolution, I consider both the benefits and the costs of light filtering in the retina. Oil droplets decrease cone quantum catch and reduce the overlap in sensitivity between spectrally adjacent cones. The reduction of spectral overlap increases the volume occupied by object colours in a cone space, whereas the decrease in quantum catch increases noise, and thus reduces the discriminability of similar colours. The trade-off between these two effects determines the total benefit of oil droplets. Calculations show that coloured oil droplets increase the number of object colours that can be discriminated, and thus are beneficial for colour vision. PMID:12816638

Vorobyev, Misha



Mobile devices and weak ties: a study of vision impairments and workplace access in Bangalore.  


Abstract Purpose: To explore ways in which social and economic interactions are changed by access to mobile telephony. Method: This is a mixed-methods study of mobile phone use among 52 urban professionals with vision impairments in Bangalore, India. Results: Interviews and survey results indicated that mobile devices, specifically those with adaptive technology software, play a vital role as multi-purpose devices that enable people with disabilities to navigate economically and socially in an environment where accessibility remains a significant challenge. Conclusions: We found that mobile devices play a central role in enabling and sustaining weak ties, but also that these weak ties have important gender-specific implications. We found that women have less access to weak ties than men, which impacts women's access to assistive technology (AT). This has potential implications for women's sense of safety and independence, both of which are strongly related to AT access. Implications for Rehabilitation Adaptive technologies increase individuals' ability to keep in contact with casual connections or weak ties through phone calls or social media. Men tend to have stronger access to weak ties than women in India due to cultural impediments to independent access to public spaces. Weak ties are an important source of assistive technology (AT) due to the high rate of resale of used AT, typically through informal networks. PMID:25358437

Pal, Joyojeet; Lakshmanan, Meera



A new abnormality of human vision provides evidence of interactions between cortical mechanisms sensitive to movement and those sensitive to colour.  


We present the results of a psychophysical study on a human observer, MW, which describe his abnormal visual responses to moving stimuli. It has been shown previously that this subject has normal vision for stationary, achromatic patterns, but responds highly abnormally to saturated chromatic, and especially red stimuli. We now report that like chromatic stimuli, moving black and white patterns elicit an inhibitory response which extends beyond the visual field area covered by the moving stimulus itself, and suppresses detection of stationary, achromatic patterns. Although both chromatic and moving stimuli generate similar percepts in association with their inhibitory activities, these latter differ in several respects, and we conclude that they have different neural origins. We show that in addition to their separate inhibitory actions on detection of achromatic patterns, movement and colour exert mutually inhibitory effects. Movement is markedly effective in limiting the inhibitory spread associated with colour, regardless of the positions in the visual field of the moving and coloured stimuli. Such spatially diffuse activity is characteristic of higher visual processing in pre-occipital cortical visual areas. PMID:8805842

Morland, A B; Ogilvie, J A; Ruddock, K H; Wright, J R



Colour vision defects in asymptomatic carriers of the Leber's hereditary optic neuropathy (LHON) mtDNA 11778 mutation from a large Brazilian LHON pedigree: a case?control study  

PubMed Central

Aims To determine if asymptomatic carriers from a previously identified large pedigree of the Leber's hereditary optic neuropathy (LHON) 11778 mtDNA mutation have colour vision deficits. Methods As part of a comprehensive analysis of over 200 members of a large Brazilian LHON pedigree spanning seven generations, colour vision tests were obtained from 91 members. Colour vision was tested one eye at a time using the Farnsworth?Munsell 100 (FM?100) hue colour vision test. The test was administered under uniform conditions, taking into account: ambient light levels, daylight colour temperature of 6700?kelvin, and neutral uniform background. Tests were scored using the FM?100 MS?Excel computer scoring program. Defects were determined and categorised as tritan, deutan, or protan. Categorisation of each dyschromatopsia was based on review of demonstrated axis computer generated plots and age adjusted error scores which coincided with Verriest 95% confidence intervals. Only the axis with the greatest magnitude error score was used to classify the defect. 55 of the 91 test subjects were LHON mtDNA 11778 J haplotype mutation carriers, proved by mtDNA analysis. The remaining 36 subjects were age matched non?blood relatives (off pedigree), who served as controls. Results 27 of 55 carriers (49.10%) were shown to have colour vision defects in one or both eyes. 13 of the 27 (48%) abnormal tests in the carrier group were tritan defects and the remaining 14 (52%) were deutan defects. Nine of the 27 (33%) abnormals in the carrier group were identified as having bilateral defects. Six of these were deutan, and the remaining three were tritan dyschromatopsias. Only six of the 36 (16.66%) age matched controls were found to have any type of dyschromatopsia. Five (83.3%) of these were deutan defects. The remaining one was a tritan defect. The difference between the two groups using a ?2 test with one degree of freedom was statistically significant with a p value less that 0.001. Conclusions Until now, LHON has always been characterised by a sudden, devastating vision loss. Asymptomatic carriers, those without vision loss, were considered unaffected by the disease. It now appears that asymptomatic carriers of the LHON mutation are affected by colour vision defects and may manifest other subtle, yet chronic, changes. PMID:16424523

Quiros, P A; Torres, R J; Salomao, S; Berezovsky, A; Carelli, V; Sherman, J; Sadun, F; De Negri, A; Belfort, R; Sadun, A A



"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

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.…

Thurston, Mhairi




NASA Technical Reports Server (NTRS)

Some data on human vision, important in present and projected space activities, are presented. Visual environment and performance and structure of the visual system are also considered. Visual perception during stress is included.

Taylor, J. H.



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

E-print Network

-ROM, free to visually impaired purchasers of the print edition. Homo sapiens are visual creatures. Thanks Handbook presents a balanced, if abbreviated, treatment of visual impairment. Readers with particular interests in visual impairment of the young or the old will find much useful material here. The chapters

Sekuler, Robert


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

PubMed Central

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

Wong, Aimée A.; Brown, Richard E.



The assessment of colour perception, naming and knowledge: a new test device with a case study.  


Besides ocular diseases, also cerebral damage may cause colour vision deficits; cerebral lesions may be associated with a variety of clinical conditions that impair colour processing. This study presents procedures and normative data for a rapid, comprehensive seven-test battery aimed at assessing colour perception, colour naming and object colour knowledge. The norms, obtained from 96 healthy Italian participants, allow normality/pathology judgements on the basis of one-sided tolerance limits, after adjusting the score of each test for the demographic variables of the proband subjects. We also report, as an example, use of the battery in a stroke patient; this patient was chosen because her lesion affected the left temporal-occipital cortex, an area sometimes associated with a deficit of colour processing. The patient resulted normal on colour perception and colour name retrieval, but defective on object colour knowledge probed using the stimulus name. For the sound definition of the functional locus of cognitive impairment at the single case level, a multi-faceted set of tasks is necessary. PMID:22076482

Pagani, Rossella; Bosco, Giovanna; Dalla Valle, Elisabetta; Capitani, Erminio; Laiacona, Marcella



Colour constancy in insects.  


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

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



Assistive obstacle detection and navigation devices for vision-impaired users.  


Quality of life for the visually impaired is an urgent worldwide issue that needs to be addressed. Obstacle detection is one of the most important navigation tasks for the visually impaired. In this research, a novel range sensor placement scheme is proposed in this paper for the development of obstacle detection devices. Based on this scheme, two prototypes have been developed targeting at different user groups. This paper discusses the design issues, functional modules and the evaluation tests carried out for both prototypes. Implications for Rehabilitation Visual impairment problem is becoming more severe due to the worldwide ageing population. Individuals with visual impairment require assistance from assistive devices in daily navigation tasks. Traditional assistive devices that assist navigation may have certain drawbacks, such as the limited sensing range of a white cane. Obstacle detection devices applying the range sensor technology can identify road conditions with a higher sensing range to notify the users of potential dangers in advance. PMID:23350879

Ong, S K; Zhang, J; Nee, A Y C



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

ERIC Educational Resources Information Center

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…

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



Randomised controlled trial of treatment of unilateral visual impairment detected at preschool vision screening  

Microsoft Academic Search

Objectives To test the efficacy of treatment for unilateral visual loss detected by preschool vision screening and the extent to which effectiveness varies with initial severity. Design Randomised controlled trial of full treatment with glasses and patching, if required, compared with glasses only or no treatment. Masked assessment of best corrected acuity after one year of follow up. Setting Eight

M P Clarke; C M Wright; S Hrisos; J D Anderson; J Henderson; S R Richardson



Spatial frequency discrimination learning in normal and developmentally impaired human vision  

E-print Network

­ commonly referred to as `lazy eye' (see Ciuffreda, Levi, & Selenow, 1991). Amblyopia is a common visual). Disruption of visual input to one eye during the critical period(s) of visual development leads to dramatic vision in one, or occasionally both eyes, despite full optical correction and no evident ocular pathology

Nottingham, University of


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

PubMed Central

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

Wahl, Hans-Werner



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

NASA Astrophysics Data System (ADS)

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.

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



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

Microsoft Academic Search

BackgroundFree-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

Dara N. Orbach; Brock Fenton; Raphaël Arlettaz



The Disability Divide: A Study into the Impact of Computing and Internet-related Technologies on People who are Blind or Vision Impaired  

Microsoft Academic Search

People with disabilities, and in particular people who are blind or vision impaired, are not embracing computing and Internet- related technologies at the same rate as the able-bodied population. The purpose of this study was to find the reasons behind this digital divide for people with disabilities and provide solutions. The investigation into this ‘disability divide’ initially examined the historical

Scott Emery Hollier



Fuzzy-based human vision properties in stereo sonification system for the visually impaired  

NASA Astrophysics Data System (ADS)

This paper presents incorporation of certain human vision properties in the image processing methodologies, applied in the vision substitutive system for human blind. The prototype of the system has digital video camera fixed in a headgear, stereo earphone and a laptop computer, interconnected. The processing of the captured image is designed as human vision. It involves lateral inhibition, which is developed using Feed Forward Neural Network (FFNN) and domination of the object properties with suppression of background by means of Fuzzy based Image Processing System (FLIPS). The processed image is mapped to stereo acoustic signals to the earphone. The sound is generated using non-linear frequency incremental sine wave. The sequence of the scanning to construct the acoustic signal is designed to produce stereo signals, which aids to locate the object in horizontal axis. Frequency variation implies the location of object in the vertical axis. The system is tested with blind volunteer and his suggestion in formatting, pleasantness and discrimination of sound pattern were also considered.

Nagarajan, Ramachandran; Yaacob, Sazali; Sainarayanan, G.



Body Mounted Vision System for Visually Impaired Outdoor and Indoor Wayfinding Assistance  

Microsoft Academic Search

The most challenging issue of the navigation assistive systems for the visually impaired is the instantaneous and accurate spatial localization of the user. Most of the previous proposed systems based on GPS sensors have clearly insufficient accuracy for pedestrian use and are confined to outdoor with severe failing in urban area. This paper presents an interesting alternative localization algorithm using

Sylvie Treuillet; Eric Royer; Thierry Chateau; Michel Dhome; Jean-marc Lavest



Low Vision Enhancement: The Use of Figure-Ground Reversals with Visually Impaired Children.  

ERIC Educational Resources Information Center

The study employed the use of field reversals--printing white and yellow foregrounds on a black background--to decrease the amount of light reflected from printed materials to the eye with 18 visually impaired children (9-14 years old). The findings indicated that neither reversals in contrast nor chromaticity differences were effective measures…

Gardner, Laurence R.



Visualizing Without Vision at the Microscale: Students With Visual Impairments Explore Cells With Touch  

NASA Astrophysics Data System (ADS)

Science instruction is typically highly dependent on visual representations of scientific concepts that are communicated through textbooks, teacher presentations, and computer-based multimedia materials. Little is known about how students with visual impairments access and interpret these types of visually-dependent instructional materials. This study explored the efficacy of new haptic (simulated tactile feedback and kinesthetics) instructional technology for teaching cell morphology and function to middle and high school students with visual impairments. The study examined students' prior experiences learning about the cell and cell functions in classroom instruction, as well as how haptic feedback technology impacted students' awareness of the 3-D nature of an animal cell, the morphology and function of cell organelles, and students' interest in the haptic technology as an instructional tool. Twenty-one students with visual impairment participated in the study. Students explored a tactile model of the cell with a haptic point probe that allowed them to feel the cell and its organelles. Results showed that students made significant gains in their ability to identify cell organelles and found the technology to be highly interesting as an instructional tool. The need for additional adaptive technology for students with visual impairments is discussed.

Jones, M. Gail; Minogue, James; Oppewal, Tom; Cook, Michelle P.; Broadwell, Bethany



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

PubMed Central

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

Orbach, Dara N.; Fenton, Brock



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


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

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



Adaptive colouration in amphibians.  


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

Rudh, Andreas; Qvarnström, Anna



Monitor, a vibrotactile aid for environmental perception: a field evaluation by four people with severe hearing and vision impairment.  


Monitor is a portable vibrotactile aid to improve the ability of people with severe hearing impairment or deafblindness to detect, identify, and recognize the direction of sound-producing events. It transforms and adapts sounds to the frequency sensitivity range of the skin. The aid was evaluated in the field. Four females (44-54 years) with Usher Syndrome I (three with tunnel vision and one with only light perception) tested the aid at home and in traffic in three different field studies: without Monitor, with Monitor with an omnidirectional microphone, and with Monitor with a directional microphone. The tests were video-documented, and the two field studies with Monitor were initiated after five weeks of training. The detection scores with omnidirectional and directional microphones were 100% for three participants and above 57% for one, both in their home and traffic environments. In the home environment the identification scores with the omnidirectional microphone were 70%-97% and 58%-95% with the directional microphone. The corresponding values in traffic were 29%-100% and 65%-100%, respectively. Their direction perception was improved to some extent by both microphones. Monitor improved the ability of people with deafblindness to detect, identify, and recognize the direction of events producing sounds. PMID:23861651

Ranjbar, Parivash; Stenström, Ingeborg



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

PubMed Central

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

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



Monitor, a Vibrotactile Aid for Environmental Perception: A Field Evaluation by Four People with Severe Hearing and Vision Impairment  

PubMed Central

Monitor is a portable vibrotactile aid to improve the ability of people with severe hearing impairment or deafblindness to detect, identify, and recognize the direction of sound-producing events. It transforms and adapts sounds to the frequency sensitivity range of the skin. The aid was evaluated in the field. Four females (44–54 years) with Usher Syndrome I (three with tunnel vision and one with only light perception) tested the aid at home and in traffic in three different field studies: without Monitor, with Monitor with an omnidirectional microphone, and with Monitor with a directional microphone. The tests were video-documented, and the two field studies with Monitor were initiated after five weeks of training. The detection scores with omnidirectional and directional microphones were 100% for three participants and above 57% for one, both in their home and traffic environments. In the home environment the identification scores with the omnidirectional microphone were 70%–97% and 58%–95% with the directional microphone. The corresponding values in traffic were 29%–100% and 65%–100%, respectively. Their direction perception was improved to some extent by both microphones. Monitor improved the ability of people with deafblindness to detect, identify, and recognize the direction of events producing sounds. PMID:23861651

Stenström, Ingeborg



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

PubMed Central

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



Robust colour calibration of an imaging system using a colour space transform and advanced regression modelling.  


A new algorithm for the conversion of device dependent RGB colour data into device independent L*a*b* colour data without introducing noticeable error has been developed. By combining a linear colour space transform and advanced multiple regression methodologies it was possible to predict L*a*b* colour data with less than 2.2 colour units of error (CIE 1976). By transforming the red, green and blue colour components into new variables that better reflect the structure of the L*a*b* colour space, a low colour calibration error was immediately achieved (?E(CAL) = 14.1). Application of a range of regression models on the data further reduced the colour calibration error substantially (multilinear regression ?E(CAL) = 5.4; response surface ?E(CAL) = 2.9; PLSR ?E(CAL) = 2.6; LASSO regression ?E(CAL) = 2.1). Only the PLSR models deteriorated substantially under cross validation. The algorithm is adaptable and can be easily recalibrated to any working computer vision system. The algorithm was tested on a typical working laboratory computer vision system and delivered only a very marginal loss of colour information ?E(CAL) = 2.35. Colour features derived on this system were able to safely discriminate between three classes of ham with 100% correct classification whereas colour features measured on a conventional colourimeter were not. PMID:22464923

Jackman, Patrick; Sun, Da-Wen; Elmasry, Gamal



Simultaneous and successive colour discrimination in the honeybee ( Apis mellifera )  

Microsoft Academic Search

The colour discrimination of individual free-flying honeybees (Apis mellifera) was tested with simultaneous and successive viewing conditions for a variety of broadband reflectance stimuli. For simultaneous viewing bees used form vision to discriminate patterned target stimuli from homogeneous coloured distractor stimuli, and for successive discrimination bees were required to discriminate between homogeneously coloured stimuli. Bees were significantly better at a

Adrian G Dyer; Christa Neumeyer



`Flight of colours' in lesions of the visual system 1  

PubMed Central

A bright pocket flashlight was directed into one eye for 10 seconds; the subject then closed the eyelids and reported the sequence of after-image colours observed. Lesions of the visual system which compromised bilateral central colour vision also reduced or abolished the `flight of colours'. This simple bedside test of each eye independently is of value in detecting mild defects of central vision. PMID:4457619

Feldman, Martin; Todman, Leo; Bender, Morris B.



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

PubMed Central

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



Blood groups, ABH saliva secretion and colour vision deficiency in Hindu castes and religious groups of West Godavari, Andhra Pradesh, India.  


The distribution of A1A2B0 and Rh(D) blood groups, ABH saliva secretion and red-green colour blindness among fourteen Hindu caste groups, besides Christian and Muslim populations of West Godavari District, Andhra Pradesh, India, is reported. All the Hindu castes except Brahmin, Kshatriya and Reddy exhibit relatively higher frequency of group B over group A. The subtyping of group A reveals that group A2 records an incidence ranging from 0.98% to 7.78%. The interpopulation chi-square tests for A1A2B0 blood group distribution indicate significant variation between several Hindu castes. The Vysya, Reddy and Adi Andhra castes not only differ from each other but also register significant variation from a majority of other populations. In the ABH saliva secretion also Vysya deviate from all other populations by recording the highest incidence (37.70%) of non-secretors, while the lowest frequency (19.98%) was observed among Kamma. The Rh(D) negative blood group is observed in all Hindu castes and religious groups with an incidence ranging from 1.04% in Vysya to 8.11% in Kamma. All the sixteen populations investigated exhibit prevalence of red-green colour blindness with a relatively higher frequency of deutan type over protan. PMID:7840536

Vijayalakshmi, M; Naidu, J M; Suryanarayana, B



Colour and urban landscape  

Microsoft Academic Search

Colour regards urban landscape of important elements, it can reflect a city's history, local features and cultural tradition. This paper discusses to colour aesthetic application in urban landscape design, namely how to play a landscape of natural colour and artificial colour features and create urban landscape beauty of colours. Keywords-colour; urban landscape; urban colour \\

Xueping Wu; Shicheng Xu



Seroepidemiology of Toxoplasma gondii infection in patients with vision and hearing impairments, cancer, HIV, or undergoing hemodialysis in Durango, Mexico.  


Toxoplasma gondii infection may cause a variety of symptoms involving virtually all organs. Little is known of the epidemiology of T. gondii infection in different patient groups in Mexico. We sought to determine the prevalence of T. gondii infection and associated epidemiological characteristics in 472 patients in Durango, Mexico. Participants were tested for T. gondii IgG and IgM antibodies. In addition, sociodemographic, clinical, and behavioral characteristics from each participant were obtained. Seroprevalences of T. gondii IgG antibodies were found in 7 (8.2%) of 85 patients with hearing impairment, 5 (10.0%) of 50 patients with hemodialysis, 28 (12.0%) of 234 patients with visual impairment, and 7 (6.8%) of 103 at risk of immunosuppression. In total, 47 (10%) of 472 subjects had IgG T. gondii antibodies; 6 (1.3%) of them also had IgM anti- T. gondii antibodies. Patients born in Durango State had a significantly lower prevalence of T. gondii infection than patients born in other Mexican states (9.0% vs. 21.4%, respectively; P < 0.05). Multivariate analysis showed that T. gondii infection was significantly associated with consumption of undercooked meat (adjusted odds ratio [OR] = 2.95; 95% confidence interval [CI]: 1.18-7.35) or raw cow's milk (adjusted OR = 2.52; 95% CI: 1.28-4.96), presence of cats at home (adjusted OR = 2.01; 95% CI: 1.06-3.78), raising animals (adjusted OR = 2.44; 95% CI: 1.06-5.63), or eating away from home (adjusted OR = 2.70; 95% CI: 1.03-7.11). In the group of patients with visual impairment, those with reflex impairment had a significantly higher frequency of T. gondii infection than those with normal reflexes (19% vs. 9.4%, respectively: P = 0.04). Results of the present study are the first step in the design of prevention programs to avoid the sequelae of toxoplasmosis. PMID:20557194

Alvarado-Esquivel, C; Liesenfeld, O; Torres-Castorena, A; Estrada-Martínez, S; Urbina-Alvarez, J D; Ramos-de la Rocha, M; Márquez-Conde, J A; Dubey, J P



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.  


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

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



Degas: Vision and Perception.  

ERIC Educational Resources Information Center

The art of Edgar Degas is discussed in relation to his impaired vision, including amblyopia, later blindness in one eye, corneal scarring, and photophobia. Examined are ways in which Degas compensated for vision problems, and dominant themes of his art such as the process of perception and spots of brilliant light. (Author/JDD)

Kendall, Richard



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

PubMed Central

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.

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



Older adults coping with vision loss.  


Age-related vision loss is one of the most commonly cited disabling impairments of adult life. Stressors presented by vision loss can create barriers, threatening the well-being of the individual. This qualitative study of 30 older adults (65 to 95 years of age) investigated vision loss and coping strategies. All participants experienced unexpected sight loss during their adult years. The Adaptation to Age-Related Vision Loss (AVL) Scale was used in this study to examine psychosocial adaptation to vision impairment. The coping strategies of vision impairment were assessed by collecting self-reported reflections toward vision loss and how the change impacted the participant's life. Given the correct balance of support, confidence, and acceptance, older adults can confront the existing barriers and focus on the ability to optimize function with vision loss. Health care service providers and practitioners can provide needed assistance and a helpful guide to assist older adults in successfully coping with vision impairment. PMID:20845173

Weber, Joseph A; Wong, Karen B



Vision Processing for the Bionic Eye (VIBE)  

E-print Network

Vision Processing for the Bionic Eye (VIBE) NICTA is creating assistive devices for visually of computer vision technologies to key problems for the visually impaired · Research in scene structure impaired people, using computer vision-based technologies. The same technologies will enable


Reduced Vision and Speechreading.  

ERIC Educational Resources Information Center

Eye disorders most likely to be experienced by a hearing-impaired person are described, with an explanation of how speechreading performance might be impacted. Recommendations are offered to assist visually impaired speechreaders, through consideration of optimal viewing angles, lighting conditions, use of low vision aids, etc. (JDD)

Karp, Adrienne



Colour Guided Colour Image Steganography  

E-print Network

Information security has become a cause of concern because of the electronic eavesdropping. Capacity, robustness and invisibility are important parameters in information hiding and are quite difficult to achieve in a single algorithm. This paper proposes a novel steganography technique for digital color image which achieves the purported targets. The professed methodology employs a complete random scheme for pixel selection and embedding of data. Of the three colour channels (Red, Green, Blue) in a given colour image, the least two significant bits of any one of the channels of the color image is used to channelize the embedding capacity of the remaining two channels. We have devised three approaches to achieve various levels of our desired targets. In the first approach, Red is the default guide but it results in localization of MSE in the remaining two channels, which makes it slightly vulnerable. In the second approach, user gets the liberty to select the guiding channel (Red, Green or Blue) to guide the r...

Amirtharajan, R; Swarup, Motamarri Abhilash; K, Mohamed Ashfaaq; Rayappan, John Bosco Balaguru



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.


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


... 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 ( ...


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


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

Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido



Synaesthesia and colour constancy.  


Grapheme-colour synaesthesia is an atypical condition characterized by the perception of colours when reading achromatic text. We investigated the level of colour processing responsible for these experiences. To do so, we tapped a central characteristic of colour perception. In different lighting conditions the same wavelength of light can prompt the perception of different colours. This helps humans recognize distinctive coloured objects despite changes in illumination. We wanted to see if synaesthetic colours were generated at a neural locus that was susceptible to colour constancy analyses. We used colour matching and naming tasks to examine interactions between simulated coloured illuminants and synaesthetic colours. Neither synaesthetic colour matching or naming was impacted. This contrasted with non-synaesthetic control participants, who performed the colour-matching task with graphemes physically coloured to mimic synaesthesia. Our data suggest that synaesthetic colour signals are not generated at lower-levels of colour processing, but are introduced at higher levels of analysis and are therefore not impacted by the processes responsible for perceptual constancy. PMID:22487049

Erskine, Holly; Mattingley, Jason B; Arnold, Derek H



Evolution and selection of trichromatic vision in primates  

Microsoft Academic Search

Trichromatic colour vision is of considerable importance to primates but is absent in other eutherian mammals. Primate colour vision is traditionally believed to have evolved for finding food in the forest. Recent work has tested the ecological importance of trichromacy to primates, both by measuring the spectral and chemical properties of food eaten in the wild, and by testing the

Alison K. Surridge; Daniel Osorio; Nicholas I. Mundy



The CCH Vision Stimulation Program for Infants with Low Vision: Preliminary Results.  

ERIC Educational Resources Information Center

This study evaluated the Columbus (Ohio) Children's Hospital vision stimulation program, involving in-home intervention with 15 visually impaired infants. Comparison with controls indicated benefits of appropriate vision stimulation in increasing the neural foundation for vision and visual-motor function in visually impaired infants. (Author/DB)

Leguire, L. E.; And Others



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

PubMed Central

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

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



Colour and lighting in hospital design  

NASA Astrophysics Data System (ADS)

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'.

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



Colour Reflection Holography  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. Requires signed TDF. The fidelity of colour reproduction achievable in reflection holograms is analysed by an in depth experimental and theoretical treatment. The experimental work consists of a comparison of materials and development of techniques for producing colour reflection holograms. Colour reflection holograms were recorded using a suitable material and various types of three-band laser illumination. Holograms recorded with the combinations 458, 529, and 633 nm or 458, 529, and 647 nm reproduced a full range of colours accurately, including yellow, dark blue, and purple images, which was impossible by previous methods. A theoretical model of the colour reproduction by holograms incorporates colour rendering analysis, effects of bandwidth, a new definition of signal to noise ratio, wavelength shifting, and colour balance. The model compares octagons formed by points on a CIE diagram corresponding to eight Munsell coloured chips when reproduced by the holographic image and when illuminated by a standard light source. Figures of merit of average vector length between image and object colours and gamut area size are considered. The theory compares well with holograms recorded of the Munsell chips using eight different sets of recording wavelengths. Holographic image colour reproduction for all possible recording wavelengths is predicted by the model. From this analysis, optimum wavelength combinations are obtained that support experimental results. In conclusion, a new definition of true colour holography is suggested that considers the quality of colour reproduction of a holographic image compared to colours viewed under normal conditions.

Hubel, Paul Matthew



Does Colour Preference Have a Role in Colour Term Acquisition?  

ERIC Educational Resources Information Center

A developmental association exists between colour preference and emerging colour term acquisition in young children. Colour preference might influence colour term acquisition by directing attention towards or away from a particular colour, making it more or less memorable. To investigate the role that colour preference may have in the acquisition…

Pitchford, Nicola J.; Davis, Emma E.; Scerif, Gaia



Vision and Driving  

PubMed Central

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

Owsley, Cynthia; McGwin, Gerald



(Computer) Vision without Sight  

PubMed Central

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

Manduchi, Roberto; Coughlan, James



Colour Measurements and Modeling  

NASA Astrophysics Data System (ADS)

The most common property to measure quality of any material is its appearance. Appearance includes colour, shape, size and surface conditions. The analysis of colour is especially an important consideration when determining the efficacy of variety of postharvest treatments. Consumers can easily be influenced by preconceived ideas of how a particular fruit or vegetable or a processed food should appear, and marketers often attempt to improve upon what nature has painted. Recently colour measurements have also been used as quality parameters and indicator of some inner constituents of the material. In spite of the significance of colour in food industries, many continue to analyze it inadequately. This chapter deals with theory of colour, colour scales and its measurement, sampling techniques, and modeling of colour values for correlating them with some internal quality parameters of selected fruits.

Jha, Shyam N.


FReD: The Floral Reflectance Database — A Web Portal for Analyses of Flower Colour  

PubMed Central

Background Flower colour is of great importance in various fields relating to floral biology and pollinator behaviour. However, subjective human judgements of flower colour may be inaccurate and are irrelevant to the ecology and vision of the flower's pollinators. For precise, detailed information about the colours of flowers, a full reflectance spectrum for the flower of interest should be used rather than relying on such human assessments. Methodology/Principal Findings The Floral Reflectance Database (FReD) has been developed to make an extensive collection of such data available to researchers. It is freely available at The database allows users to download spectral reflectance data for flower species collected from all over the world. These could, for example, be used in modelling interactions between pollinator vision and plant signals, or analyses of flower colours in various habitats. The database contains functions for calculating flower colour loci according to widely-used models of bee colour space, reflectance graphs of the spectra and an option to search for flowers with similar colours in bee colour space. Conclusions/Significance The Floral Reflectance Database is a valuable new tool for researchers interested in the colours of flowers and their association with pollinator colour vision, containing raw spectral reflectance data for a large number of flower species. PMID:21170326

Savolainen, Vincent; McOwan, Peter W.; Chittka, Lars




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 in a Civil Union ­ Medical, Dental and Term Life Benefits". How VSP Works: STEP ONE: To obtain vision care


Brand Guidelines Colour version  

E-print Network

Brand Guidelines Overview May 2012 #12;Colour version Shield alone Black Colour reverse Colour reverse on red Reverse Brand Overview 1.2 The Signature Our signature system is comprised of two elements and Reverse require special version of the shield, available upon request. #12;1x ¼x ¼x ¼x ¼x ¼x¼x Brand

Shoubridge, Eric


Teaching Visually Impaired Children. Second Edition.  

ERIC Educational Resources Information Center

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

Bishop, Virginia E.


Colourful FKS subtraction  

E-print Network

I formulate in a colour-friendly way the FKS method for the computation of QCD cross sections at the next-to-leading order accuracy. This is achieved through the definition of subtraction terms for squared matrix elements, constructed with single colour-dressed or pairs of colour-ordered amplitudes. The latter approach relies on the use of colour flows, is exact to all orders in $N$, and is thus particularly suited to being organized as a systematic expansion in 1/N.

Stefano Frixione



Robert Grosseteste's colours  

E-print Network

Here I am proposing a translation and discussion of the De Colore, one of the short scientific treatises written by Robert Grosseteste. In this very short treatise of the mid-1220s, Grosseteste continued the discussion on light and colours he started in the De Iride. He describes two manners of counting colours: one gives an infinity of tones, the other counts seven colours. In both cases, colours are created by the purity or impurity of the transparent medium when light is passing through it. This medieval framework survived until Newton's experiments with prisms.

Sparavigna, Amelia Carolina



Development and evaluation of vision rehabilitation devices.  


We have developed a range of vision rehabilitation devices and techniques for people with impaired vision due to either central vision loss or severely restricted peripheral visual field. We have conducted evaluation studies with patients to test the utilities of these techniques in an effort to document their advantages as well as their limitations. Here we describe our work on a visual field expander based on a head mounted display (HMD) for tunnel vision, a vision enhancement device for central vision loss, and a frequency domain JPEG/MPEG based image enhancement technique. All the evaluation studies included visual search paradigms that are suitable for conducting indoor controllable experiments. PMID:22255516

Luo, Gang; Peli, Eli



Reading aids for adults with low vision  

PubMed Central

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) (, the metaRegister of Controlled Trials (mRCT) (, ( and the WHO International Clinical Trials Registry Platform (ICTRP) ( 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

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



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

E-print Network

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

Reimchen, Thomas E.


Increased conspicuousness can explain the match between visual sensitivities and blue plumage colours in fairy-wrens  

PubMed Central

Colour signals are expected to match visual sensitivities of intended receivers. In birds, evolutionary shifts from violet-sensitive (V-type) to ultraviolet-sensitive (U-type) vision have been linked to increased prevalence of colours rich in shortwave reflectance (ultraviolet/blue), presumably due to better perception of such colours by U-type vision. Here we provide the first test of this widespread idea using fairy-wrens and allies (Family Maluridae) as a model, a family where shifts in visual sensitivities from V- to U-type eyes are associated with male nuptial plumage rich in ultraviolet/blue colours. Using psychophysical visual models, we compared the performance of both types of visual systems at two tasks: (i) detecting contrast between male plumage colours and natural backgrounds, and (ii) perceiving intraspecific chromatic variation in male plumage. While U-type outperforms V-type vision at both tasks, the crucial test here is whether U-type vision performs better at detecting and discriminating ultraviolet/blue colours when compared with other colours. This was true for detecting contrast between plumage colours and natural backgrounds (i), but not for discriminating intraspecific variability (ii). Our data indicate that selection to maximize conspicuousness to conspecifics may have led to the correlation between ultraviolet/blue colours and U-type vision in this clade of birds. PMID:23118438

Delhey, Kaspar; Hall, Michelle; Kingma, Sjouke A.; Peters, Anne



Quantitative Luminance And Colour Representation With CRT Displays  

NASA Astrophysics Data System (ADS)

Colour displays in image processing admit grey scales as well as colour scales for the visual representation of image information. Pseudocolours can be used to enhance the discriminability of different parts of the image. Luminance scales, on the other hand, are preferred for representing fine detail as human colour vision is limited to relatively low spatial frequencies. In the present paper, the generation of quantitative luminance and colour scales with CRT displays is discussed. This includes the colour characteristics of CRTs as well as a recapitulation of the CIE 1931 (X, Y, Z) tristimulus colorimetry system. The CIE 1976 UCS diagram (u', v') is used as an approximation to a perceptually uniform representation of chromaticity. On this basis, it is shown how, for each pixel, luminance and colour (hue) can be chosen independently. In order to add colour as a further visual dimension to greyscale images, a set of equiluminant hues is proposed for each luminance level. The hues are chosen from equidistant steps around a circle in the (u', v') chromaticity diagram. This choice of colours is particularly suitable for the visual representation of a cyclic quantity like phase angle.

Brettel, Hans



Low Vision Enhancement System  

NASA Technical Reports Server (NTRS)

NASA's Technology Transfer Office at Stennis Space Center worked with the Johns Hopkins Wilmer Eye Institute in Baltimore, Md., to incorporate NASA software originally developed by NASA to process satellite images into the Low Vision Enhancement System (LVES). The LVES, referred to as 'ELVIS' by its users, is a portable image processing system that could make it possible to improve a person's vision by enhancing and altering images to compensate for impaired eyesight. The system consists of two orientation cameras, a zoom camera, and a video projection system. The headset and hand-held control weigh about two pounds each. Pictured is Jacob Webb, the first Mississippian to use the LVES.



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...


Animat Vision: Active Vision in  

E-print Network

Article 1 Animat Vision: Active Vision in Artificial Animals Demetri Terzopoulos, Tamer F. Rabie Videre: Journal of Computer Vision Research Quarterly Journal Fall 1997, Volume 1, Number 1 The MIT Press Videre: Journal of Computer Vision Research (ISSN 1089-2788) is a quarterly journal published

Terzopoulos, Demetri


The Physical Environment and the Visually Impaired.  

ERIC Educational Resources Information Center

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…

Braf, Per-Gunnar


ColourVis: exploring colour usage in paintings over time  

Microsoft Academic Search

The colour palette of painters over history has been of interest to many, including: art historians, archeologists, and art lovers. Colour usage in art changes from culture to culture and season to season and is often thought of as reflecting or inspiring mood and ambience. We present ColourVis: a visualization that supports exploration of colour usage in digital images. In

Jonathan Haber; Sean Lynch; Sheelagh Carpendale



Quantitative spore colour measurement using colour image analysis  

Microsoft Academic Search

The colour changes that spores exhibit, with increasing depth of burial, are used as a thermal maturity indicator for evaluating hydrocarbon source rocks. Spore colour is determined visually leading to an intrinsic difficulty of unequivocally assessing and recording their colour. Quantitative scales using photometers are available, but are not widely applied. Colour Image Analysis (CIA) is presented here as an

B Yule; S Roberts; J. E. A Marshall; J. A Milton



Compound heterozygous microdeletion of chromosome 15q13.3 region in a child with hypotonia, impaired vision, and global developmental delay.  


Homozygous or compound heterozygous microdeletion of 15q13.3 region is a rare but clinically recognizable syndrome manifested by profound intellectual disability, muscular hypotonia, intractable seizures, and visual impairment. We identified a compound heterozygous 15q13.3 microdeletion in a 23-month-old girl with global developmental delay, generalized muscular hypotonia, and visual dysfunction. The larger deletion was approximately 1.28?Mb in size and contained seven genes including the TRPM1 and CHRNA7, while the smaller deletion was estimated to be 410?Kb in size and contained only CHRNA7. Compound heterozygous 15q13.3 microdeletion is extremely rare and to the best of our knowledge only two such patients have been reported in literature thus far. The findings in our patient suggest that the pathogenesis of visual dysfunction, which is a consistent finding in homozygous/compound heterozygous 15q13.3 microdeletion depends upon the size of microdeletion. Homozygous loss of TRPM1 likely causes retinal dysfunction while homozygous loss of CHRNA7 alone may lead to visual impairment by cortical mechanisms. PMID:24700535

Prasun, Pankaj; Hankerd, Michael; Kristofice, Melissa; Scussel, Lindsey; Sivaswamy, Lalitha; Ebrahim, Salah



Colour Mixing Based on Daylight  

ERIC Educational Resources Information Center

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…

Meyn, Jan-Peter



Signal functions of carotenoid colouration  

E-print Network

The importance of carotenoids for natural colouration, in relation to other classes of pigments and structural colours, has been outlined in Chapter 10. But colour only has significance if it is perceived, identified and interpreted by other organisms (animals). In other words, colour is a means of communication, a signal. Now, in this Chapter, this new direction for carotenoid

Jonathan D. Blount; Kevin J. Mcgraw



Low Vision  


... Prevalence Rates for Low Vision by Age, and Race/Ethnicity Age White Black Hispanic Other All 40- ... 04% 2010 Prevalence Rates of Low Vision by Race All White Black Hispanic Other Prevalence 0.020 ...


Vision Screening  


... regular well care office visits. In addition, many day care programs, churches, schools and health departments offer vision ... addition to vision screening that is offered at day care, school or church. In some states a documented ...


Arch Intern Med . Author manuscript Visual impairment, optical correction, and their impact on activity  

E-print Network

Arch Intern Med . Author manuscript Page /1 3 Visual impairment, optical correction ; therapy ; Vision, Low ; therapy ; Visual Acuity ; Visually Impaired Persons ; rehabilitation ; statistics to difficulty performing activities of daily life. In elderly, visual impairment is one of the major

Paris-Sud XI, Université de


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.  


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

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



Efficacy of a Low Vision Patient Consultation  

ERIC Educational Resources Information Center

A variety of obstacles can prevent persons or individuals with low vision from deriving the greatest possible benefit from the rehabilitation process, including inadequate understanding of their visual impairment, lack of knowledge about available services, and misconceptions about low vision devices. This study explores the use of a…

Siemsen, Dennis W.; Bergstrom, A. Ren?e; Hathaway, Julie C.



Neurological Vision Rehabilitation: Description and Case Study  

ERIC Educational Resources Information Center

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…

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



The Iowa Model for Pediatric Low Vision Services.  

ERIC Educational Resources Information Center

This article describes the evolution of Iowa's model of low vision care for students with visual impairments. It reviews the benefits of a transdisciplinary team approach to providing low vision services for children with visual impairments, including a decrease in the number of students requiring large-print materials and related costs. (Contains…

Wilkinson, Mark E.; Stewart, Ian; Trantham, Carole S.



Age-Related Psychophysical Changes and Low Vision  

PubMed Central

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

Dagnelie, Gislin



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

PubMed Central

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

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



Low-cost wearable low-vision aid using a handmade retinal light-scanning microdisplay  

E-print Network

) is a portable system that uses machine vision to track potential walking hazards for the visually impaired onto the retina to display warning icons that the visually impaired can recognize. Initial low-vision subject testing has given promising results for this low-cost assistive device. Keywords -- Low vision

Washington at Seattle, University of


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

ERIC Educational Resources Information Center

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…

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



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

ERIC Educational Resources Information Center

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…

Pinquart, Martin; Pfeiffer, Jens P.



No role for colour in symmetry perception  

Microsoft Academic Search

Bilateral colour symmetry, such as that evident in a Siberian tiger's face (Fig. 1a), is relevant to many animals,, including humans,. We examined the role of colour in symmetry perception by asking observers to detect colour symmetry in regular grids of coloured squares (a colour-symmetrical image has regions of the same colour located equidistantly from a vertical axis). Our results

Dawn Morales; Harold Pashler



Colour cues proved to be more informative for dogs than brightness  

PubMed Central

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

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



The Improvement of Vision by Vision Stimulation and Training: A Review of the Literature.  

ERIC Educational Resources Information Center

This article reviews the theoretical and research literature on vision stimulation and vision training of children with severe irreversible visual impairments. It recommends early stimulation to prevent visual deprivation, use of operant conditioning, and the presentation of highly contrasting stimuli to stimulate visual awareness in children with…

Tavernier, G. G. F.



Vision multiplexing: An optical engineering concept for low-vision aids  

Microsoft Academic Search

The normal visual system provides a wide field of view apparently at high resolution. The wide field is continuously monitored at low resolution for navigation and detection of objects of interest. These objects are sampled using the high- resolution fovea, applying a temporal multiplexing scheme. Most vision impairments that cause low vision impact upon only one of the components; the

Eli Peli



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

E-print Network

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

Mullen, Kathy T.


The Role of Organizations in Reaching Older Adults about Vision Loss  

ERIC Educational Resources Information Center

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…

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



Machine Vision  

NSDL National Science Digital Library

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.

Leske, Cavin.


Computer vision  

NASA Technical Reports Server (NTRS)

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.

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



Texture Variations Suppress Suprathreshold Brightness and Colour Variations  

PubMed Central

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

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



Class Separation Improvements in Pixel Classification Using Colour Injection  

PubMed Central

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 (YC1C2) 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

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



Vision Underwater.  

ERIC Educational Resources Information Center

Provides information regarding underwater vision. Includes a discussion of optically important interfaces, increased eye size of organisms at greater depths, visual peculiarities regarding the habitat of the coastal environment, and various pigment visual systems. (CS)

Levine, Joseph S.



Improving Vision  

NASA Technical Reports Server (NTRS)

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.



The colours of the Sun  

E-print Network

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.

Johan Holmberg; Chris Flynn; Laura Portinari



Mouse Simulation Using Two Coloured Tapes  

E-print Network

In this paper, we present a novel approach for Human Computer Interaction (HCI) where, we control cursor movement using a real-time camera. Current methods involve changing mouse parts such as adding more buttons or changing the position of the tracking ball. Instead, our method is to use a camera and computer vision technology, such as image segmentation and gesture recognition, to control mouse tasks (left and right clicking, double-clicking, and scrolling) and we show how it can perform everything as current mouse devices can. The software will be developed in JAVA language. Recognition and pose estimation in this system are user independent and robust as we will be using colour tapes on our finger to perform actions. The software can be used as an intuitive input interface to applications that require multi-dimensional control e.g. computer games etc.

Kumar, Vikram; Mahe, Swapnil; Vyawahare, Swapnil; 10.5121/ijist.2012.2206



Stereo-based Aerial Obstacle Detection for the Visually Impaired  

E-print Network

Stereo-based Aerial Obstacle Detection for the Visually Impaired Juan Manuel S´aez Mart of the algorithm in several situations using real data. 1 Introduction In the visually impaired context manuscript, published in "Workshop on Computer Vision Applications for the Visually Impaired, Marseille

Paris-Sud XI, Université de


Shrinking Spaces and Occupational Options: The Experiences of Older Adults With Low Vision Living in Urban and Rural Settings  

Microsoft Academic Search

Older adults are the fastest growing segment of individuals with visual impairments in industrialized countries. Among the older adult population, low vision, that is a degree of vision impairment that cannot be corrected with standard eyeglasses, becomes more prevalent and is more likely to be untreated with increasing age. Although previous research suggests low vision negatively impacts on older adults’

Debbie Rudman Laliberte; Lisa Linger; Suzanne Huot; Beverley D. Leipert



SingleColour and SingleFlavour Colour Superconductivity  

E-print Network

Chromodynamics (QCD) predicts that at high density, such as that found within the core of a compact star, cold interactions, as is required when modelling compact stars, the situation changes. These e#ects introduce colour a study of single­flavour and other spin­1 colour supercon­ ducting condensates in a survey of generic

Low, Robert


Digital colour management system for colour parameters reconstruction  

NASA Astrophysics Data System (ADS)

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.

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




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. How VSP Works: STEP ONE: To obtain vision care services, call your VSP doctor. To locate a VSP network


Across light: through colour  

NASA Astrophysics Data System (ADS)

The speed at which our world is changing is reflected in the shifting way artistic images are created and produced. Holography can be used as a medium to express the perception of space with light and colour and to make the material and the immaterial experiments with optical and digital holography. This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new experimental methodologies applied to holographic images. Holography is a time-based medium and the irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space? Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR CX105.

Azevedo, Isabel; Richardson, Martin; Bernardo, Luis Miguel



Visual Impairment: The Use of Visual Profiles in Evaluations of Icon Use in Computer-Based Tasks  

Microsoft Academic Search

This research investigates an empirical link between characteristics of impaired vision and user performance on computer-based systems. The underlying premise of this re- search is twofold: specific aspects of visual dysfunction can be linked to the task perfor- mance demonstrated by computer users with impaired vision, and graphical user in- terfaces can be modified to evoke enhanced performance from low-vision

Julie A. Jacko; Robert H. Rosa Jr.; Ingrid U. Scott; Charles J. Pappas; Max A. Dixon




Microsoft Academic Search

The colour terms of Irish have been discussed by a number of scholars, usually with an emphasis on Old Irish or in comparison with other Celtic languages. Lazar-Meyn (1991) has in addition interviewed speakers of the modern Celtic languages in order to study their use of colour terms, although she correctly notes that this area of the lexicon has come

Diarmuid Ó Sé


Complementary Colours for a Physicist  

ERIC Educational Resources Information Center

This paper reports on a simple experiment which enables splitting incident light into two different modes, each having a colour exactly complementary to the other. A brief historical development of colour theories and differences in a physicist's point of view with respect to an artist's one is discussed. An experimental system for producing…

Babic, Vitomir; Cepic, Mojca



Low Vision FAQs  


... at NEI Education Programs Training and Jobs Healthy Vision Diabetes Diabetes Home How Much Do You Know? ... los Ojos Cómo hablarle a su oculista Low Vision FAQs Listen What is low vision? Low vision ...


Automated image analysis as a tool to quantify the colour and composition of rainbow trout  

E-print Network

scanned images of trout cutlets, and included quality traits such as fat percentage, flesh colour.08.009 #12;of fish for quality traits. Automated image analysis, also called machine vision, is an efficient and non-invasive tool for measuring quality traits in fish and other food products (Brosnan and Sun, 2004

Manne, Fredrik


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

Microsoft Academic Search

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

Ulrike E. Siebeck



Vision system for ALV  

Microsoft Academic Search

In this paper an integrated vision system for autonomous land vehicle is described. The vision system includes 2D vision, 3D vision, and information fusion. The task of 2D vision is to provide physical information and 3D vision is to detect obstacles in the surrounding. The 2D and 3D information fusion can generate a feasible region provided for vehicle.

Xiuqing Ye; Jilin Liu; Weikang Gu



Colours Core palette Colours Core palette APPLYING THE GUIDELINES  

E-print Network

) (web and screen) Bright aqua 3262 C81 M0 Y36 K0 r0 G192 B181 #00C0B5 Dark aqua 309 C99 M27 Y22 K80 r0 G THE GUIDELINES Colours Colour breakdowns for print and web Colour Pantone® CMYK RGB Hex (special) (professional and desktop printing) (web and screen) (web and screen) university red 187 C0 M91 Y72 K23 r171 G31 B45 #B01C2e

Bristol, University of


Assessment of Citrus Fruit Quality Using a Real-Time Machine Vision System  

Microsoft Academic Search

Spain is a major producer of citrus fruit, which must be correctly classified depending on its external quality. Current commercial sorters based on machine vision cannot solve problems like defect detection or correct colour classification due to the low image resolution, which is necessary to achieve adequate production speed. This paper describes a new machine vision system to classify different

N. Aleixos; José Blasco; Enrique Moltó; F. Navarrón



A Time-Efficient Cascade for Real-Time Object Detection: With applications for the visually impaired.  

E-print Network

st International Workshop on Computer Vision Applications for the Visually Impaired (CVACVI system which can be used for applications to help the blind and visually impaired. 1. Introduction Real in designing computer vision systems to help the blind and visually impaired. In particular, we want algorithms

Yuille, Alan L.


Arrested Vision  

Microsoft Academic Search

“Arrested Vision” looks at how photographs and buildings mediate visual relationships among people, offering framed bits of life and chance encounters. Referring to what Roland Barthes called “the sexuality of sight,” the author observes how the gaze migrates and, when arrested, sustains tension. Photographs such as those of Diane Arbus invite us to look at something that fascinates, however briefly,

Henry Urbach



Active vision  

Microsoft Academic Search

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

John Aloimonos; Isaac Weiss; Amit Bandyopadhyay



Omnidirectional Vision  

Microsoft Academic Search

Conventional video cameras have limited fields of view that make them re- strictive in a variety of vision applications. There are several ways to enhance the field of view of an imaging system. However, the entire imaging system must have a single effective viewpoint to enable the generation of pure per- spective images from a sensed image. A camera with

Shree K. Nayar



Presidential Visions.  

ERIC Educational Resources Information Center

This journal issue is devoted to the theme of university presidents and their visions of the future. It presents the inaugural addresses and speeches of 16 Catholic college and university presidents focusing on their goals, ambitions, and reasons for choosing to become higher education leaders at this particular time in the history of education in…

Gallin, Alice, Ed.



Postural and visual loads at VDT workplaces II. Lighting conditions and visual impairments  

Microsoft Academic Search

Four groups of office tasks were studied: data entry terminals, conversational terminals, traditional office work and typing. Eye impairments were observed in every group of office employees but the impairments were more frequent in VDT operators. The impairments persisted during leisure time. Vision screening tests showed the same incidence of functional eye impairments in office tasks with and without VDTs.




Minimizing unsatisfaction in colourful neighbourhoods  

NASA Astrophysics Data System (ADS)

Colouring sparse graphs under various restrictions is a theoretical problem of significant practical relevance. Here we consider the problem of maximizing the number of different colours available at the nodes and their neighbourhoods, given a predetermined number of colours. In the analytical framework of a tree approximation, carried out at both zero and finite temperatures, solutions obtained by population dynamics give rise to estimates of the threshold connectivity for the incomplete to complete transition, which are consistent with those of existing algorithms. The nature of the transition as well as the validity of the tree approximation are investigated.

Wong, K. Y. Michael; Saad, David



Optimal colour quality of LED clusters based on memory colours.  


The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant. PMID:21451716

Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter



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

Microsoft Academic Search

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

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



Colour preferences of flower-naive honeybees  

Microsoft Academic Search

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

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



What Colour Is a Shadow?  

ERIC Educational Resources Information Center

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…

Hughes, S. W.



Lambda Vision  

NASA Astrophysics Data System (ADS)

There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

Czajkowski, Michael



A head-mounted, image transceiver-based, low vision aid  

Microsoft Academic Search

A mobile, head-mounted low vision aid is critically needed for the vision impaired. We report here on a new effort centered around a unique Image Transceiver Device (ITD) combining both functions of imaging and display in a single CMOS chip. The device will allow a compact design of a low vision goggle in which the imager part will capture the

U. Efron; I. David; B. Apter; N. Thirer; I. Baal Zedaka; A. Ben-Guigui; O. Levy; P. Nater



Computer Vision Technology for Applications to Assist Blind Dr. Ying-Li Tian, Associate Professor  

E-print Network

Computer Vision Technology for Applications to Assist Blind People Dr. Ying-Li Tian, Associate in computer vision, digital cameras, and portable computers make it possible to develop practical computer for applying computer vision technologies to assist people who are visually impaired including indoor

Zhu, Zhigang


The global burden of trachomatous visual impairment: II. assessing burden  

Microsoft Academic Search

This paper builds on results of a previous paper on the prevalence of trachomatous visual impairment as the foundation for assessing the global burden of trachomatous blindness and low vision: approximately 2.9 million cases of trachomatous blindness and 3.8 million low visioned corresponding to a global prevalence of trachomatous visual impairment equal to 1.3\\/1,000 in 1990 was estimated. For each

Timothy G. Evans; M. Kent Ranson



The Secret World of Shrimps: Polarisation Vision at Its Best  

PubMed Central

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

Kleinlogel, Sonja; White, Andrew G.




Microsoft Academic Search

Quantum dots are a newly developed nanotechnology that has the potential to restore impaired vision. We will explain what quantum dots are, how they operate, and how they are made, including the material makeup and fabrication processes. We will then proceed by giving brief background information about the composition of the eye and how it functions. Furthermore, we will explain

Catherine Nalesnik


Vision Therapy News Backgrounder.  

ERIC Educational Resources Information Center

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…

American Optometric Association, St. Louis, MO.


The Social Lives of Canadian Youths with Visual Impairments  

ERIC Educational Resources Information Center

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.)

Gold, Deborah; Shaw, Alexander; Wolffe, Karen



Italy: Early Intervention with Visually Impaired Children with Additional Handicaps.  

ERIC Educational Resources Information Center

Describes a private, early (birth to four) therapeutic intervention center in Italy that provides short-term intensive treatment to children with severe visual impairments and possible additional disabilities. The residential program emphasizes maximum use of residual vision, vision stimulation and training, psychological counseling for parents,…

Goergen, E.



Taste - impaired  


... 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 ...


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


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

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



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.



Living with Low Vision  

MedlinePLUS Videos and Cool Tools

... Tips Podcasts Text Messages Vision-Related Terms, Selected Online Sources For Professionals Low Vision Low Vision Home ... NEI Office of Science Communications, Public Liaison, and Education. Technical questions about this website can be addressed ...


Ophthalmological, cognitive, electrophysiological and MRI assessment of visual processing in preterm children without major neuromotor impairment.  


Many studies report chronic deficits in visual processing in children born preterm. We investigated whether functional abnormalities in visual processing exist in children born preterm but without major neuromotor impairment (i.e. cerebral palsy). Twelve such children (< 33 weeks gestation or birthweight < 1000 g) without major neuromotor impairment and 12 born full-term controls were assessed at 8-12 years of age by means of ophthalmological assessment (visual acuity, colour vision, stereopsis, stereoacuity, visual fields, ocular motility, motor fusion), cognitive tests of visual-motor, visual-perceptual and visual-spatial skills and pattern-reversal visual evoked potentials (PR-VEPs). All participants also underwent magnetic resonance imaging (MRI) of the brain and neuromotor assessments. No significant differences were found between the groups on the ophthalmological, visual cognitive, neurological, neuromotor or MRI measures. The P100 component of the PR-VEP showed a significantly shorter latency in the preterm compared with the full-term participants. Whilst this P100 finding suggests that subtle abnormalities may exist at the neurophysiological level, we conclude that visual dysfunction is not systematically associated with preterm birth in the context of normal neurological status. PMID:20712735

O'Reilly, Michelle; Vollmer, Brigitte; Vargha-Khadem, Faraneh; Neville, Brian; Connelly, Alan; Wyatt, John; Timms, Chris; de Haan, Michelle



Low Vision Aids and Low Vision Rehabilitation  


... The future will offer even more solutions. Newer technology for low vision aids While low vision devices ... magnifiers have long been the standard in assistive technology, advances in consumer electronics are also improving quality ...


Ecological genomics in full colour.  


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

Hohenlohe, Paul A



Identity Development in German Adolescents with and without Visual Impairments  

ERIC Educational Resources Information Center

Introduction: The study reported here assessed the exploration of identity and commitment to an identity in German adolescents with and without visual impairments. Methods: In total, 178 adolescents with visual impairments (blindness or low vision) and 526 sighted adolescents completed the Ego Identity Process Questionnaire. Results: The levels of…

Pinquart, Martin; Pfeiffer, Jens P.



Clin. Vision Sci. Vol. 6, No.1, pp. 49-57, 1990 Printed in Great Britain. All rights reserved  

E-print Network

Clin. Vision Sci. Vol. 6, No.1, pp. 49-57, 1990 Printed in Great Britain. All rights reserved H. FOSTER,l WILLIAM P. HONAN,2 JAMES R. HERON,2 MARTIN C. GULLIFORD3 and JOHN H. B. SCARPELL03 l of reduced stimulus duration on colour vision were assessed in two pathologies differentially affecting

Foster, David H.


Colour Appearance and Colour Rendering of HDR Scenes: An Experiment  

Microsoft Academic Search

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

Carinna Parraman; Alessandro Rizzi; John J. McCannc


Animat Vision: Active Vision in Artificial Animals  

Microsoft Academic Search

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.

Demetri Terzopoulos; Tamer F. Rabie



Positive emotion can protect against source memory impairment.  


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

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



Vision Screening  

NASA Technical Reports Server (NTRS)

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.



Robot Vision  

NASA Technical Reports Server (NTRS)

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.

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



Quark interactions and colour chemistry  

Microsoft Academic Search

The interaction between quarks, according to the current theory of quantum chromo-dynamics, is formally rather similar to the electromagnetic interaction between electrons and nucleons, both being governed by locally gauge-invariant field theories. It is tempting therefore to discuss the spectroscopy of hadrons, which are quark composites bound by colour forces, in the same language as the spectroscopy of atoms and

Chan Hong-Mo



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

NASA Astrophysics Data System (ADS)

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.

Leyk, Stefan


All about Low Vision  


... 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 ...


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

NASA Astrophysics Data System (ADS)

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.

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.



Summing large- towers in colour flow evolution  

NASA Astrophysics Data System (ADS)

We consider soft-gluon evolution in the colour flow basis. We give explicit expressions for the colour structure of the (one-loop) soft anomalous dimension matrix for an arbitrary number of partons, and we show how the successive exponentiation of classes of large- contributions can be achieved to provide a systematic expansion of the evolution in terms of colour-suppressed contributions.

Plätzer, Simon



Colour space models for soil science  

Microsoft Academic Search

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

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



Genetics of novel corolla colours in periwinkle  

Microsoft Academic Search

Inheritance of a novel corolla colour in periwinkle [Catharanthus roseus (L) G. Don], viz. magenta, was studied by crossing an accession MJ, possessing this corolla colour, with cultivar Nirmal, possessing white corolla. The accession MJ was also crossed with another accession OR, possessing another novel corolla colour, viz. orange-red, to determine the relationship between genes governing magenta corolla and orange-red

R. N. Kulkarni; K. Baskaran; Y. Sreevalli



An RGB Approach to Prismatic Colours  

ERIC Educational Resources Information Center

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…

Theilmann, Florian; Grusche, Sascha



Biological Components of Colour Preference in Infancy  

ERIC Educational Resources Information Center

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…

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



(Computer vision and robotics)  

SciTech Connect

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.

Jones, J.P.



Equipping Designers by Simulating the Effects of Visual and Hearing Impairments  

E-print Network

Equipping Designers by Simulating the Effects of Visual and Hearing Impairments Joy Goodman that demonstrates the effects of common vision and hearing impairments on image and sound files. This helps their products and interfaces. A range of impairments and severity levels are simulated and guidance is provided

Goodman, Joy


Visual impairment, optical correction and their impact on activity limitations in the The POLA Study.  

E-print Network

1 Visual impairment, optical correction and their impact on activity limitations in the elderly of visual impairment. "Low vision" (including blindness) and "Moderate visual impairment" were defined and physical deficiencies and ultimately to difficulty performing activities of daily life. In elderly, visual

Paris-Sud XI, Université de


Digital enhancement of television signals for people with visual impairments: Evaluation of a consumer product  

E-print Network

Digital enhancement of television signals for people with visual impairments: Evaluation with visual impairment require higher levels of contrast than normally sighted persons to see most stimuli of such a device on the preference for enhanced video was tested for people with impaired vision and normally

Peli, Eli


Post-transmission digital video enhancement for people with visual impairments Matthew Fullerton  

E-print Network

Post-transmission digital video enhancement for people with visual impairments Matthew Fullerton and video for people with visual impairments. The MPEG coding scheme makes spatial filtering, likely to help, television, vision rehabilitation, image enhancement, visual impairment, adap- tion, artifact, quantization

Peli, Eli


Sonification of Images for the Visually Impaired using a Multi-Level Approach  

E-print Network

Sonification of Images for the Visually Impaired using a Multi-Level Approach Michael Banf & Volker presents a system that strives to give visually impaired persons direct perceptual access to images via, Design, Experimentation Keywords Sonification, Visually Impaired, Computer Vision, Machine Learning

Blanz, Volker


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

ERIC Educational Resources Information Center

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…

Carroll, Pamela S.; Rosenblum, L. Penny


Colour annealing - a toy model of colour reconnections  

SciTech Connect

We present a simple toy model for colour reconnections at the nonperturbative level. The model resembles an annealing-type algorithm and is applicable to any collider and process type, though we argue for a possible enhancement of the effect in hadron-hadron collisions. We present a simple application and study of the consequences for semileptonic t{bar t} events at the Tevatron.

Sandhoff, Marisa; /Wuppertal U.; Skands, Peter; /Fermilab



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

PubMed Central

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

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



Vision and falls in older people: risk factors and intervention strategies.  


Poor vision impairs balance and increases the risk of falls and fractures in older people. Multifocal glasses can add to this risk by impairing contrast sensitivity, depth perception, and ability to negotiate obstacles. Vision assessment and provision of new spectacles may not reduce, and may even increase, the risk of falls. Restriction of the use of multifocal glasses may reduce falls in active older people. Other effective fall prevention strategies include maximizing vision through cataract surgery and occupational therapy interventions in visually impaired older people. PMID:20934611

Lord, Stephen R; Smith, Stuart T; Menant, Jasmine C



Digital enhancement of haematoxylin- and eosin-stained histological images for red-green colour-blind observers.  


Individuals with red-green colour-blindness (CB) commonly experience great difficulty differentiating between certain histological stain pairs, notably haematoxylin-eosin (H&E). The prevalence of red-green CB is high (6-10% of males), including among medical and laboratory personnel, and raises two major concerns: first, accessibility and equity issues during the education and training of individuals with this disability, and second, the likelihood of errors in critical tasks such as interpreting histological images. Here we show two methods to enhance images of H&E-stained samples so the differently stained tissues can be well discriminated by red-green CBs while remaining usable by people with normal vision. Method 1 involves rotating and stretching the range of H&E hues in the image to span the perceptual range of the CB observers. Method 2 digitally unmixes the original dyes using colour deconvolution into two separate images and repositions the information into hues that are more distinctly perceived. The benefits of these methods were tested in 36 volunteers with normal vision and 11 with red-green CB using a variety of H&E stained tissue sections paired with their enhanced versions. CB subjects reported they could better perceive the different stains using the enhanced images for 85% of preparations (method 1: 90%, method 2: 73%), compared to the H&E-stained original images. Many subjects with normal vision also preferred the enhanced images to the original H&E. The results suggest that these colour manipulations confer considerable advantage for those with red-green colour vision deficiency while not disadvantaging people with normal colour vision. PMID:19493108

Landini, G; Perryer, G



Printing colour at the optical diffraction limit.  


The highest possible resolution for printed colour images is determined by the diffraction limit of visible light. To achieve this limit, individual colour elements (or pixels) with a pitch of 250 nm are required, translating into printed images at a resolution of ?100,000 dots per inch (d.p.i.). However, methods for dispensing multiple colourants or fabricating structural colour through plasmonic structures have insufficient resolution and limited scalability. Here, we present a non-colourant method that achieves bright-field colour prints with resolutions up to the optical diffraction limit. Colour information is encoded in the dimensional parameters of metal nanostructures, so that tuning their plasmon resonance determines the colours of the individual pixels. Our colour-mapping strategy produces images with both sharp colour changes and fine tonal variations, is amenable to large-volume colour printing via nanoimprint lithography, and could be useful in making microimages for security, steganography, nanoscale optical filters and high-density spectrally encoded optical data storage. PMID:22886173

Kumar, Karthik; Duan, Huigao; Hegde, Ravi S; Koh, Samuel C W; Wei, Jennifer N; Yang, Joel K W



Selection on quantitative colour variation in Centaurea cyanus: the role of the pollinator's visual system.  


Even though the importance of selection for trait evolution is well established, we still lack a functional understanding of the mechanisms underlying phenotypic selection. Because animals necessarily use their sensory system to perceive phenotypic traits, the model of sensory bias assumes that sensory systems are the main determinant of signal evolution. Yet, it has remained poorly known how sensory systems contribute to shaping the fitness surface of selected individuals. In a greenhouse experiment, we quantified the strength and direction of selection on floral coloration in a population of cornflowers exposed to bumblebees as unique pollinators during 4 days. We detected significant selection on the chromatic and achromatic (brightness) components of floral coloration. We then studied whether these patterns of selection are explicable by accounting for the visual system of the pollinators. Using data on bumblebee colour vision, we first showed that bumblebees should discriminate among quantitative colour variants. The observed selection was then compared to the selection predicted by psychophysical models of bumblebee colour vision. The achromatic but not the chromatic channel of the bumblebee's visual system could explain the observed pattern of selection. These results highlight that (i) pollinators can select quantitative variation in floral coloration and could thus account for a gradual evolution of flower coloration, and (ii) stimulation of the visual system represents, at least partly, a functional mechanism potentially explaining pollinators' selection on floral colour variants. PMID:24070120

Renoult, J P; Thomann, M; Schaefer, H M; Cheptou, P-O



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


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

Horridge, Adrian



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

PubMed Central

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

Horridge, Adrian



Quark interactions and colour chemistry  

NASA Astrophysics Data System (ADS)

The interaction between quarks, according to the current theory of quantum chromo-dynamics, is formally rather similar to the electromagnetic interaction between electrons and nucleons, both being governed by locally gauge-invariant field theories. It is tempting therefore to discuss the spectroscopy of hadrons, which are quark composites bound by colour forces, in the same language as the spectroscopy of atoms and molecules which are bound states of electrons and nucleons held together by e.m. forces. Because of the difference in gauge groups, however, the dynamics are very different. Nonetheless, it appears likely that metastable multiquark hadron states can exist which are analogous to atoms and molecules in QED. In these lectures, tentative steps are taken in developing the rudiments of a new ‘colour chemistry’ of these ‘atoms’ and ‘molecules’.

Hong-Mo, Chan


Matrix models and graph colouring  

NASA Astrophysics Data System (ADS)

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.

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



Colour Image Segmentation: A Survey  

Microsoft Academic Search

Image segmentation, i.e., identi#cation of homogeneous regions in the image, hasbeen the subject of considerable research activityover the last three decades. Manyalgorithms have been elaborated for gray scale images. However, the problem ofsegmentation for colour images, which convey much more information about objectsin scenes, has received much less attention of scienti#c community. While severalsurveys of monochrome image segmentation techniques were

Wladyslaw Skarbek; Andreas Koschan



Vision multiplexing: an optical engineering concept for low-vision aids  

NASA Astrophysics Data System (ADS)

The normal visual system provides a wide field of view apparently at high resolution. The wide field is continuously monitored at low resolution for navigation and detection of objects of interest. These objects are sampled using the high-resolution fovea, applying a temporal multiplexing scheme. Most vision impairments that cause low vision impact upon only one of the components; the peripheral low-resolution wide field or the central high-resolution fovea. The loss of one of these components prevents the interplay of central and peripheral vision needed for normal function and causes disability. Traditional low-vision aids improve the impacted component, but usually at a cost of a significant loss in the surviving component. For example, magnifying devices increase resolution but reduce the field of view, while minifying devices increase the field of view but reduce resolution. A general optical engineering approach - vision multiplexing - is presented. Vision multiplexing seeks to provide both the wide field of view and the high-resolution information in ways that could be accessed and interpreted by the visual system. The use of various optical and electro-optical methods in the development of a number of new visual aids, all of which apply vision multiplexing to restore the interplay of high-resolution and wide-angle vision using eye movements in a natural way, will be described. Vision-multiplexing devices at various stages of development and testing illustrate the successes and difficulties in applying this approach for patients with tunnel vision, hemianopia (half blindness), and visual acuity loss (usually due to central retinal disease).

Peli, Eli



Ultraviolet vision and foraging in dip and plunge diving birds  

PubMed Central

Many fishes are sensitive to ultraviolet (UV) light and display UV markings during courtship. As UV scatters more than longer wavelengths of light, these signals are only effective at short distances, reducing the risk of detection by swimming predators. Such underwater scattering will be insignificant for dip and plunge diving birds, which prey on fishes just below the water surface. One could therefore expect to find adaptations in the eyes of dip and plunge diving birds that tune colour reception to UV signals. We used a molecular method to survey the colour vision tuning of five families of dip or plunge divers and compared the results with those from sister taxa of other foraging methods. We found evidence of extended UV vision only in gulls (Laridae). Based on available evidence, it is more probable that this trait is associated with their terrestrial foraging habits rather than piscivory. PMID:17148194

Håstad, Olle; Ernstdotter, Emma; Ödeen, Anders



The original colours of fossil beetles  

PubMed Central

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

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



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

PubMed Central

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

Théry, Marc; Casas, Jérôme



Blindness and vision loss  


... as chemical burns or sports injuries) Diabetes Glaucoma Macular degeneration The type of partial vision loss may differ, depending on the cause: With cataracts , vision may be cloudy or fuzzy, and bright ...


Computer vision on tap  

E-print Network

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 ...

Chiu, Kevin Geeyoung


Quantifying Plant Colour and Colour Difference as Perceived by Humans Using Digital Images  

PubMed Central

Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management. PMID:23977275

Kendal, Dave; Hauser, Cindy E.; Garrard, Georgia E.; Jellinek, Sacha; Giljohann, Katherine M.; Moore, Joslin L.



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


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

Lefevre, Carmen E; Perrett, David I



Management Benefits Program VISION PLAN  

E-print Network

Management Benefits Program VISION PLAN Administered by National Vision Administrators years of age, orthoptics, vision training, and tonography. · · · · · Your vision plan is being administered by National Vision Administrators. If you have questions or require information, call or write: National Vision

Hardy, Christopher R.


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


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

Llaurens, V; Joron, M; Théry, M



Computer Vision Bildverarbeitung  

E-print Network

1 1 Computer Vision Bildverarbeitung Bernd Neumann WS 2007 2 IMAGE PROCESSING FOR MULTIMEDIA, Analysis and Machine Vision (3. Ed.) M. Sonka, V. Hlavac, R. Boyle, Thomson 2008 Grundlagen der Bildverarbeitung K.D. Tönnies, Pearson Studium, 2005 Computer Vision - A Modern Approach D.A. Forsyth, J. Ponce



Cataract Vision Simulator  


... the Sun Eye Health News Consumer Alerts Cataract Vision Simulator Tweet How do cataracts affect your vision? A cataract is a clouding of the eye's ... when the signs of disease and changes in vision may start to occur. Follow Us Related Ask ...


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


Low Vision Simulations  


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 ...


VISION2015 ...................................................................1  

E-print Network

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 2 () 2015 3 8 () 9

Hung, Shih-Hao


Computer vision systems  

Microsoft Academic Search

Still today, the majority of publications in computer vision focuses on component technologies. However, computer vision has reached a level of maturity that allows not only to perform research on individual methods and system components but also to build fully integrated computer vision systems of significant complexity. This opens a number of new problems related to system architecture and integration,

Bernt Schiele; Gerhard Sagerer



Robot Vision Library  

NASA Technical Reports Server (NTRS)

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

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



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


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

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



3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision Topic 1 of Part II Camera Models CSC I6716 Spring2011 Zhigang Zhu, City College of New York 3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

Zhu, Zhigang


3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

3D Computer Vision and Video Computing 3D Vision3D Vision CSC I6716 Fall 2010 Topic 1 of Part II Camera Models Zhigang Zhu, City College of New York #12;3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

Zhu, Zhigang


Prevalence of Low Vision in Elderly Patients Admitted to an Acute Geriatric Unit in Liverpool: Elderly People Who Fall Are More Likely to Have Low Vision  

Microsoft Academic Search

The prevalence of visual impairment among elderly patients admitted to hospital is unknown. This group of patients may be particularly at risk from poor vision which could jeopardise their independence. A prospective study of visual impairment and its aetiology in acute geriatric admissions assessed after the acute illness had settled was performed. Subjects were all patients aged 65 years or

C. I. A. Jack; T. Smith; C. Neoh; M. Lye; J. N. McGalliard



Computational approaches to vision  

NASA Technical Reports Server (NTRS)

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.

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



Microwave vision for robots  

NASA Technical Reports Server (NTRS)

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.

Lewandowski, Leon; Struckman, Keith



Assessment and Management of Children with Visual Impairment  

PubMed Central

Purpose: The aim of this work was to evaluate the role of low vision aids in improving visual performance and response in children with low vision. Study Design: Prospective clinical case series. Materials and Methods: This study was conducted on 50 patients that met the international criteria for a diagnosis of low vision. Their ages ranged from 5 to 15 years. Assessment of low vision included distance and near visual acuity assessment, color vision and contrast sensitivity function. Low vision aids were prescribed based on initial evaluation and the patient's visual needs. Patients were followed up for 1 year using the tests done at the initial examination and a visual function assessment questionnaire. Results: The duration of visual impairment ranged from 1 to 10 years, with mean duration ± SD being 4.6± 2.3299. The near visual acuities ranged from A10 to A20, with mean near acuity ± SD being A13.632 ± 3.17171. Far visual acuities ranged from 6/60 (0.06) to 6/24 (0.25), with mean far visual acuity ± SD being 0.122 ± 0.1191. All patients had impaired contrast sensitivity function as tested using the vision contrast testing system (VCTS) chart for all spatial frequencies. Distance and near vision aids were prescribed according to the visual acuity and the visual needs of every patient. All patients in the age group 5-7 years could be integrated in mainstream schools. The remaining patients that were already integrated in schools demonstrated greater independency regarding reading books and copying from blackboards. Conclusion: Our study confirmed that low vision aids could play an effective role in minimizing the impact of low vision and improving the visual performance of children with low vision, leading to maximizing their social and educational integration. PMID:20142963

Labib, Taha A.; El Sada, Mohamed A.; Mohamed, Boshra; Sabra, Neveen M.; Abdel Aleem, Hanan M.



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

PubMed Central

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

Parrish, R K



Geometric algebra colour image representations and derived total orderings for morphological operators Part I: Colour quaternions  

E-print Network

Geometric algebra colour image representations and derived total orderings for morphological is the first part of a series of studies which focus on defining colour total orderings based on geometric algebra represen- tations of colour images. In particular, in this article we focus on real quaternions



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

Microsoft Academic Search

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




'Unnatural Colours': An introduction to colouring techniques in silent era movies  

Microsoft Academic Search

'Natural colour' was the term coined for genuine colour photography to separate it from colouring or 'painting' monochrome images, hence the use of the contrasting term 'unnatural'. The intention of this paper is to provide a guide to the technical literature on the subject. It reviews where the technologies originated, the principle literature of the time, and later, that describes

Paul Read



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

Microsoft Academic Search

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

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



Low vision goggles: optical design studies  

NASA Astrophysics Data System (ADS)

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.

Levy, Ofer; Apter, Boris; Efron, Uzi



Vision screening in older adults on dialysis: do nephrology nurses have a role?  


Undetected vision loss commonly occurs in older adults adding undue stress to those on dialysis. Poor vision is associated with increased risk of falls and decreased quality of life. Common visual impairments--presbyopia, cataracts, age-related macular degeneration, glaucoma, and diabetic retinopathy--often are detectable by visual acuity testing. Using various methods of visual acuity testing, nephrology nurses can perform vision testing quickly and inexpensively. Other nursing interventions also can improve eyesight. PMID:9392737

Richbourg, M J



Teaching Math to Visually Impaired Students  

NSDL National Science Digital Library

This page has the following resources for math teachers of the visually impaired: teaching strategies, math education and Nemeth Code, tactile math graphics, abacus information, calculators, math tools, math resources, adaptive tools and technology for accessible mathematics, suggested adaptive tools and materials for low vision students in algebra and geometry, suggested adaptive tools and materials for Braille students in algebra and geometry, and adaptive tools and technology for accessible mathematics equipment.

Osterhaus, Susan



Head-mounted mobility aid for low vision using scene classification techniques M R Everingham1  

E-print Network

on a head mounted display using a high saturation colour scheme where each type of object has a different by over 100% using the system. Keywords: Low Vision, Mobility Aids, Head Mounted Display, Object, with the development of head mounted displays and cameras for the virtual reality field, work has attempted to apply

Everingham, Mark


Mineralization in Rust-coloured Acarospora  

Microsoft Academic Search

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

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



Colour polymorphism in birds: causes and functions  

Microsoft Academic Search

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

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



Measurement of skin colour in vivo  

Microsoft Academic Search

Synopsis--Surface colours can be measured by a number of METHODS based on REFLECTOMETRY, COLORIMETRY and VISUAL STANDARDS. In both humans and animals, difficulties arise because the SKIN COLOUR may change owing to changes in blood flow, caused by the pressure exerted by the measuring instrument, because the skin surface is easily deformed, and because it may be impossible to take




Quaternionic wavelet transform for colour images  

Microsoft Academic Search

Quaternionic Wavelet Transform (QWT) already exist but it dealt with greyscale images. In this paper we propose a quaternionic wavelet transform aimed to colour image processing. To encode colour information in our new transformation, a pixel in the spatial domain is represented by a quaternion as described by Sangwine. First, we propose to use the discrete quaternionic Fourier transform to

Philippe Carré; Patrice Denis



The Aurora Borealis and its Colours  

Microsoft Academic Search

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

Warren de La Rue; Hugo Müller



Pigment chemistry and colour of Pelargonium flowers  

Microsoft Academic Search

The major factors responsible for colour variation in a range of Pelargonium species and cultivars were shown to be the types and relative levels of pigments present. Variations in pH and copigment levels were not found to contribute significantly. Flowers with colours ranging from cream and pink through to deep purple, including salmon, orange and red, were studied. While either

Kevin A. Mitchell; Kenneth R. Markham; Murray R. Boase



Instant colour photography: chemistry and UV stabilization  

Microsoft Academic Search

An ultraviolet (UV) screening agent precursor, dinonylphenylisophthalate, applied as a component of a surface coating on instant colour positive photographic prints stabilizes the dyes that are used and prevents the fading of colour that otherwise occurs. It is believed that upon exposure to UV light the ester precursor rearrangesin situ to form substituted benzophenones, which are effective UV screening agents.

A. M. Usmani; I. O. Salyer



Representing Object Colour in Language Comprehension  

ERIC Educational Resources Information Center

Embodied theories of cognition hold that mentally representing something "red" engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task…

Connell, Louise



Group Vision Care Policy Vision Care for Life  

E-print Network

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

New Mexico, University of


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

E-print Network

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) 2013/14 Your Blue View Vision Insight Network Blue View Vision Insight offers you

California at Santa Cruz, University of


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

E-print Network

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

Barrett, Jeffrey A.


Envision UCSC Vision Conference 1 UC Santa Cruz Vision Conference  

E-print Network

Envision UCSC Vision Conference 1 UC Santa Cruz Vision Conference April 16, 2014 Shared Visions and people matter #12;Envision UCSC Vision Conference 2 Group 3 On-boarding and off-boarding prep Vision Conference 3 o Increased metrics of student success (for all groups) Mentorship Navigating

California at Santa Cruz, University of


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


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

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



Colour-rendition properties of solid-state lamps  

Microsoft Academic Search

The applicability of colour-quality metrics to solid-state light sources is validated and the results of the assessment of colour-rendition characteristics of various lamps are presented. The standard colour-rendering index metric or a refined colour-quality scale metric fails to distinguish between two principle colour-rendition properties of illumination: the ability to render object colours with high fidelity and the ability to increase

A. Zukauskas; R. Vaicekauskas; M. S. Shur



3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Spring 2011 Topic 3 of Part II Stereo Vision p g Zhigang Zhu, City College of New York 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images

Zhu, Zhigang


3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Fall 2010 Topic 3 of Part II Stereo Vision Zhigang Zhu, City College of New York 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images taken

Zhu, Zhigang


Mobile Visual Aid Tools for Users with Visual Impairments  

Microsoft Academic Search

\\u000a In this chapter we describe “MobileEye”, a software suite which converts a camera enabled mobile device into a multi-function\\u000a vision tool that can assist the visually impaired in their daily activities. MobileEye consists of four subsystems, each customized\\u000a for a specific type of visual disabilities: A color channel mapper which can tell the visually impaired different colors;\\u000a a software based

Xu Liu; David S. Doermann; Huiping Li



Methods of Reading Information on Labels of Prescription Medications by Persons Who Are Visually Impaired  

ERIC Educational Resources Information Center

The prevalence of visual impairment (that is, blindness and low vision) is increasing in the United States, especially in persons aged 65 and older, with more than half of all people who are blind in this age demographic. It has been estimated that about 6.5 million Americans aged 55 and older report vision loss, and this number is expected to…

McMahon, John M.; Curtis, Amy



Age and Visual Impairment Decrease Driving Performance as Measured on a Closed-Road Circuit  

Microsoft Academic Search

In this study the effects of visual impairment and age on driving were investigated and related to visual function. Participants were 139 licensed drivers (young, middle-aged, and older participants with normal vision, and older participants with ocular disease). Driving performance was assessed during the daytime on a closed-road driving circuit. Visual performance was assessed using a vision testing battery. Age

Joanne M. Wood



The Impact of Vision Loss on Personality Traits  

ERIC Educational Resources Information Center

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…

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



Improving stoma management in the low-vision patient  

Microsoft Academic Search

Teaching the low-vision patient with an ostomy to manage a stoma independently provides a significant challenge for the WOC nurse. Although guide strips, lighted mirrors, and other handheld devices are available to patients with impaired eyesight, these products, when used alone, may be inadequate for the patient with an ostomy. In addition, there is a paucity of literature available to

Candace Jeffres; Arthur T. MacKay



Emotion-Induced Trade-Offs in Spatiotemporal Vision  

ERIC Educational Resources Information Center

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…

Bocanegra, Bruno R.; Zeelenberg, Rene



FPGA Vision Data Architecture  

NASA Technical Reports Server (NTRS)

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.

Morfopoulos, Arin C.; Pham, Thang D.



Adaptation to Low Vision Caused by Age-Related Macular Degeneration: A Case Study  

ERIC Educational Resources Information Center

One in eight Americans aged 65 and older has an eye disease resulting in low vision, and more women than men are visually impaired, mainly because women live longer. Age-related visual impairments are an indicator of a decline in activities of daily living and self-help skills. The top eye conditions that affect older adults are macular…

Smith, Theresa Marie



Artificial human vision camera  

NASA Astrophysics Data System (ADS)

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.

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



Physicochemical and physiological basis of dichromatic colour  

NASA Astrophysics Data System (ADS)

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.

Kreft, Samo; Kreft, Marko



Colloidal approach to prepare colour blends from colourants with different solubility profiles.  


Food colouring plays a vital and a determining role in the processing and the manufacturing of food products because the appearance of products is critical for attracting consumers and influencing their food choices. However, factors such as legislative restrictions, limited number of approved colourants and the processing, formulation and stability issues of the natural colourants severely limits the application of food colouring in actual product formats. Hence, finding alternatives to the currently utilised formulation practises, represents an important area of research. Here, we report a simple colloidal approach to prepare colour blends by co-incorporating colourants with contrasting aqueous solubility profiles in composite colloidal particles. Curcumin and indigocarmine were selected as water insoluble and water soluble food-grade colourants respectively and incorporated in the colloidal particles prepared from food protein-zein. Composite particles obtained by loading of curcumin and indigocarmine (at different ratios) had mean particle size ranging from 76 to 300nm. The spherical shape of the colloidal particles was confirmed using transmission electron microscopy and the colloidal dispersions were further characterised using UV-Vis and fluorescence spectroscopy. The incorporation of colourants in colloidal particles led to the generation of different shade of colour in yellow-green-blue range. The encapsulation also led to the stabilization of individual pigments against photodegradation. Such composite colloidal particles could potentially serve as an approach for developing tuneable colouring system for food and nutraceutical applications. PMID:23790940

Patel, A R; Heussen, P C M; Dorst, E; Hazekamp, J; Velikov, K P



The colour wheels of art, perception, science and physiology  

NASA Astrophysics Data System (ADS)

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.

Harkness, Nick



Detection of colour change in moving objects: temporal order judgment and reaction time analysis.  


The time needed to detect changes in the colouration of a single moving stimulus becomes shorter with its increasing velocity (Kreegipuu et al, 2006 Vision Research 46 1848-1855). We examined the ability to detect colour change in moving chromatic bars or sinusoidal gratings through temporal order judgment (TOJ) and reaction time (RT) tasks to test whether the effect of velocity found in a previous study is universal and holds for different tasks and stimuli. The results demonstrate that the TOJ and simple RT to the colour change of a moving grating are insensitive to stimulus velocity. Therefore, we conclude that the process of comparison of the two internal representations of external events does not have access to temporal information precise enough to estimate the exact time when something enters our subjective awareness. The motion effect on colour-change perception seems to be confined to a single stimulus that moves across the visual field, to events that contain some spatial predictability, and to tasks that reflect the time of the change relatively directly. PMID:20120263

Murd, Carolina; Kreegipuu, Kairi; Allik, Jüri



Near Vision Test for Adults  


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 ...


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


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

Wollenberg, K C; Measey, C John



INSIGHT: Vision & Leadership, 2002.  

ERIC Educational Resources Information Center

This publication focuses on promising new and emerging technologies and what they might mean to the future of K-12 schools. Half of the volume contains articles devoted in some way to "Vision," and articles in the other half are under the heading of "Leadership." Contents in the "Vision" section include: "The Future of Reading and Learning To…

McGraw, Tammy, Ed.



Vision North Texas  

E-print Network

is dead!? Don Gatzke Dean of Architecture University of Texas at Arlington ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 Vision North Texas ESL-KT-11-11-18 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 Vision North Texas...

Walz, K.



Vision Texture for Annotation  

Microsoft Academic Search

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

Rosalind W. Picard; Thomas P. Minka



Computer Vision Jana Kosecka  

E-print Network

. Forsyth, J. Ponce, Prentice Hall 2002) · Image Processing, Analysis, and Machine Vision. Sonka, Hlavac (with Image Processing toolbox) · Open CV library #12;2 Textbooks Project Deadlines · Check Web site). ­ Domain of vision: biological (eye+brain), computational IMAGE SYNTHESIS: image-formation process

Kosecka, Jana


Autonomic Computer Vision Systems  

Microsoft Academic Search

For most real applications of computer vision, variations in operating conditions result in poor reliability. As a result, real world applications tend to require lengthy set-up and frequent intervention by qualified specialists. In this paper we describe how autonomic computing can be used to reduce the cost of installation and enhance reliability for practical computer vision systems. We begin by

James L. Crowley; Daniela Hall; Remi Emonet



New Term, New Vision?  

ERIC Educational Resources Information Center

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…

Ravenhall, Mark



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

ERIC Educational Resources Information Center

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…

Schoch, Christina Sigrid



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

ERIC Educational Resources Information Center

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…

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



Training motor skills of children with low vision.  


The aim of this study was to study the effectiveness of a motor training program for visually impaired children. 40 children with low vision took part in the study. 20 children (10 boys, 10 girls), mean age 8:9 yr.:mo. (SD= 1:6), were in a Training group and 20 children (10 boys, 10 girls), mean age 8:10 yr.:mo. (SD= 1:65), were in a Home Training group. The Snellen Chart and Bruininks Oseretsky Motor Proficiency Test were used for assessment. Training program included training balance, coordination, strength, visuomotor control, and finger dexterity. Significant differences were found on all skills after training in the Training group, but no significant differences were observed, other than visual motor control, in the Home Training group. Children with low vision have some useable vision and learning to use the available vision depends on proper rehabilitation. PMID:17879667

Aki, Esra; Atasavun, Songül; Turan, Ay?e; Kayihan, Hülya



Multiple Disabilities and Visual Impairment: An Action Research Project  

ERIC Educational Resources Information Center

Children with visual and motor disabilities constitute a distinct group with a unique set of educational needs. Such children are often grouped with the broader population of children with multiple disabilities and visual impairments (that is, those who are blind or have low vision) (Erin, 2000; McLinden, 1997). The chief characteristic of…

Argyropoulos, Vassilios; Thymakis, Paraskevas



The Abacus: Instruction by Teachers of Students with Visual Impairments  

ERIC Educational Resources Information Center

Introduction: This article, based on a study of 196 teachers of students with visual impairments, reports on the experiences with and opinions related to their decisions about instructing their students who are blind or have low vision in the abacus. Methods: The participants completed an online survey on how they decide which students should be…

Amato, Sheila; Hong, Sunggye; Rosenblum, L. Penny



A National Video Library for Teacher Preparation in Visual Impairments  

ERIC Educational Resources Information Center

This article presents the findings of the first phase of a multiyear funded project whose ultimate purpose is to clearly define and then create a video clip library of 8- to 10-minute video clips that demonstrate exemplary teaching practices for working with students who are visually impaired (that is, those who are blind or have low vision).…

Trief, Ellen; Lengel, Jim; Baecher, Laura



Neural-Based Visual Stimulation with Infants with Cortical Impairment.  

ERIC Educational Resources Information Center

In order to shed light on the needs of children with cortical visual impairments, normal visual development of infants is described. Infant preferences for motion, faces, and black-and-white patterns are explained. Colors useful in stimulating vision development and the time needed for exposure to visual stimuli are discussed. (CR)

Powell, S. A.



[Low-Vision Training For Better Usage of Magnifying Visual Aids].  


During 1990-1991 263 low-vision aids were prescribed to visually impaired elderly people. 22% of them did not use their magnifying systems. With the help of a low-vision trainer, who taught them how to use their magnifying system correctly, the failure rate could be remarkably reduced. In 1992, low-vision aids were prescribed to 121 of 158 patients; 110 of these patients had low-vision training. Only 3% of them failed to use the magnifying system. PMID:8183531

Langmann, A; Lindner, S; Kollegger, E



The economic impact and cost of visual impairment in Australia  

PubMed Central

Aims To quantify the total economic costs of vision loss in Australia. Methods Prevalence data of visual impairment, unpublished data on indirect costs, and national healthcare cost databases were used. Results Vision disorders cost Australia an estimated A$9.85 billion in 2004. A$4.8 billion is the loss of wellbeing (years of life lost as a result of disability and premature mortality). Vision disorders rank seventh and account for 2.7% of the national loss of wellbeing. Direct health system costs total A$1.8 billion. They have increased by A$1 billion over the last 10?years and will increase a further A$1–2 billion in the next 10?years. Cataract, the largest direct cost, takes 18% of expenditure. The health system costs place vision disorders seventh, ahead of coronary heart disease, diabetes, depression, and stroke. Indirect costs, A$3.2 billion, include carers' costs, low vision aids, lost earnings, and other welfare payments and taxes. Conclusions Even a developed economy such as Australia's cannot afford avoidable vision loss. Priority needs to be given to prevent preventable vision loss; to treat treatable eye diseases; and to increase research into vision loss that can be neither prevented nor treated. PMID:16488942

Taylor, H R; Pezzullo, M L; Keeffe, J E



Panoramic stereo sphere vision  

NASA Astrophysics Data System (ADS)

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.

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



David R. Hilbert Colour, Theories of  

E-print Network

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

Hilber, David


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

Microsoft Academic Search

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

A. Schwetka



The inheritance of fruit colour in apple (Malus pumila Mill.)  

E-print Network

The inheritance of fruit colour in apple (Malus pumila Mill.) Allan G. WHITE Yves LESPINASSE that red fruit colour was determined by two dominant complementary genes. Blush and red colour did key words : Skin colour, hybridization. R�SUM� Hérédité de la couleur du fruit chez le pommier (Malus

Paris-Sud XI, Université de


Salience of Primary and Secondary Colours in Infancy  

ERIC Educational Resources Information Center

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…

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



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

PubMed Central

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

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



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

PubMed Central

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

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




SciTech Connect

In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classical gluon fields appropriate for the Colour Glass, and end with a derivation and discussion of the renormalization group equations which determine this effective theory.




Colouring Solutions of the Ice Problem  

NASA Astrophysics Data System (ADS)

The ice problem on a lattice can be expressed in terms of arrow configurations on bonds with equal numbers of arrows pointing to and away from the vertices. In some cases vertex (ice) models can be expressed as colouring problems. We use the colouring association in conjunction with an old heuristic argument of Pauling to (re)derive the exact results for the residual entropy of ice on the square and triangular lattices.

Thompson, Colin J.



Federal regulation of vision enhancement devices for normal and abnormal vision  

NASA Astrophysics Data System (ADS)

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.

Drum, Bruce



Flower colour adaptation in a mimetic orchid  

PubMed Central

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

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



Colourful parrot feathers resist bacterial degradation  

PubMed Central

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

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



Impact of colour adjustment on flavour stability of pale lager beers with a range of distinct colouring agents  

Microsoft Academic Search

The impact of colour adjustment on the flavour stability of five pale lager beers with a range of colouring agents such as specialty malts, colouring beer and artificial caramel colourant was investigated. The research focused on determination of the endogenous anti-oxidative potential (EAP) of the beer samples using a novel Electron Spin Resonance (ESR) method. The results were correlated with

Andrés Furukawa Suárez; Thomas Kunz; Natalia Cortés Rodríguez; James MacKinlay; Paul Hughes; Frank-Jürgen Methner



NeatVision: A Development Environment for Machine Vision  

E-print Network

$ NeatVision: A Development Environment for Machine Vision Engineers By Paul F. Whelan, Robert for machine vision engineers. The environment provides high-level access to a wide range of image manipulation in adopting such a system for machine vision application development. $.1 Introduction For many novices

Whelan, Paul F.


Vision 2020 |LSU Residential Colleges Program Vision 2020  

E-print Network

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

Harms, Kyle E.


Perceptual Annotation: Measuring Human Vision to Improve Computer Vision  

E-print Network

Perceptual Annotation: Measuring Human Vision to Improve Computer Vision Walter J. Scheirer, Member--For many problems in computer vision, human learners are considerably better than machines. Humans possess Ã? 1 INTRODUCTION FOR many classes of problems, the goal of computer vision is to solve visual

Nakayama, Ken


VIRTUAL VISION Virtual Reality Subserving Computer Vision Research  

E-print Network

Chapter 1 VIRTUAL VISION Virtual Reality Subserving Computer Vision Research for Camera Abstract Computer vision and sensor networks researchers are increasingly mo- tivated to investigate networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach

Qureshi, Faisal Z.


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.


Identifying solutions to medication adherence in the visually impaired elderly.  


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

Smith, Miranda; Bailey, Trista



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

PubMed Central

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

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



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


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

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



Stereo vision and strabismus.  


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.Eye advance online publication, 5 December 2014; doi:10.1038/eye.2014.279. PMID:25475234

Read, J C A



Using Computer Vision to Access Appliance Displays  

PubMed Central

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.

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



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

ERIC Educational Resources Information Center

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…

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




E-print Network

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

Casavant, Tom


Wavefront Aberrations and Peripheral Vision  

E-print Network

Wavefront Aberrations and Peripheral Vision LINDA LUNDSTRÃ?M 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


Computational Architectures for Responsive Vision  

E-print Network

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: Abstract To respond actively to a dynamic environment, a vision system must

Little, Jim


Vision systems-an overview  

Microsoft Academic Search

Vision is one of the most difficult core technologies, but is essential for robotic automation. Human vision is so natural that it is hard to appreciate the complexities of creating it artificially, but vision is the only thing holding back the development of truly autonomous machine systems. Machine vision systems are designed to eliminate or reduce human observation and error,

Brian Lasher; Mysore Narayanan



Capturing natural-colour 3D models of insects for species discovery and diagnostics.  


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

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



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

PubMed Central

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

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



Flower colour and cytochromes P450.  


Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) and thus they play a crucial role in the determination of flower colour. F3'H and F3'5'H mostly belong to CYP75B and CYP75A, respectively, except for the F3'5'Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3'5'H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3'5'H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3'5'H and F3'H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. PMID:23297355

Tanaka, Yoshikazu; Brugliera, Filippa



Flower colour and cytochromes P450†  

PubMed Central

Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3?-hydroxylase (F3?H) and flavonoid 3?,5?-hydroxylase (F3?5?H) and thus they play a crucial role in the determination of flower colour. F3?H and F3?5?H mostly belong to CYP75B and CYP75A, respectively, except for the F3?5?Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3?5?H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3?5?H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3?5?H and F3?H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones. PMID:23297355

Tanaka, Yoshikazu; Brugliera, Filippa



Colour preferences and coloured bait consumption by weka Gallirallus australis, an endemic New Zealand rail  

Microsoft Academic Search

Native birds are among the non-target species that are killed in poisoning operations directed at introduced mammalian pests in New Zealand. By identifying colours that birds find unattractive, and incorporating them into poisonous baits, some deaths may be avoided. The colour preferences of weka, Gallirallus australis, an endemic New Zealand rail, were tested over 6 days by offering individual weka

Lynette Hartley; Joseph Waas; Cheryl O'Connor; Lindsay Matthews



Colour within an internalist framework: The role of 'colour' in the structure of the perceptual system  

Microsoft Academic Search

Colour is, according to prevailing orthodoxy in perceptual psychology, a kind of autonomous and unitary attribute. It is regarded as unitary or homogeneous by assuming that its core properties do not depend on the type of 'perceptual object' to which it pertains and that 'colour per se' constitutes a natural attribute in the functional architecture of the perceptual system. It

Rainer Mausfeld


Speech impairment (adult)  


Language impairment; Impairment of speech; Inability to speak; Aphasia; Dysarthria; Slurred speech; Dysphonia voice disorders ... Common speech and language disorders include: APHASIA Aphasia is ... understand or express spoken or written language. It commonly ...


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.


A Vision Potpourri  

E-print Network

This paper discusses some recent changes and additions to the vision system. Among the additions are the ability to use visual feedback when trying to acurately position an object and the ability to use the arm as a sensory ...

Finin, Tim


Correlation of consumer assessment of longissimus dorsi beef palatability with image colour, marbling and surface texture features.  


A new study was conducted to apply computer vision methods successfully developed using trained sensory panel palatability data to new samples with consumer panel palatability data. The computer vision methodology utilized the traditional approach of using beef muscle colour, marbling and surface texture as palatability indicators. These features were linked to corresponding consumer panel palatability data with the traditional approach of partial least squares regression (PLSR). Best subsets were selected by genetic algorithms. Results indicate that accurate modelling of likeability with regression models was possible (r(2)=0.86). Modelling of other important palatability attributes proved encouraging (tenderness r(2)=0.76, juiciness r(2)=0.69, flavour r(2)=0.78). Therefore, the current study provides a basis for further expanding computer vision methodology to correlate with consumer panel palatability data. PMID:20374825

Jackman, Patrick; Sun, Da-Wen; Allen, Paul; Brandon, Karen; White, Anna-Marie



Adapting for Impaired Patrons.  

ERIC Educational Resources Information Center

Describes how a library, with an MCI Corporation grant, approached the process of setting up computers for the visually impaired. Discusses preparations, which included hiring a visually-impaired user as a consultant and contacting the VIP (Visually Impaired Persons) group; equipment; problems with the graphical user interface; and training.…

Schuyler, Michael



The vision trap.  


At Mentor Graphics Corporation, Gerry Langeler was the executive responsible for vision, and vision, he discovered, has the power to weaken a strong company. Mentor helped to invent design-automation electronics in the early 1980s, and by the end of the decade, it dominated the industry. In its early days, fighting to survive, Mentor's motto was Build Something People Will Buy. Then when clear competition emerged in the form of Daisy Systems, a startup that initially outsold Mentor, the watchword became Beat Daisy. Both "visions" were pragmatic and immediate. They gave Mentor a sense of purpose as it developed its products and gathered momentum. Once Daisy was beaten, however, company vision began to self-inflate. As Mentor grew more and more successful, Langeler formulated vision statements that were more and more ambitious, grand, and inspirational. The company traded its gritty determination to survive for a dream of future glory. The once explicit call for effective action became a fervid cry for abstract perfection. The first step was Six Boxes, a transitional vision that combined goals for success in six business areas with grandiose plans to compete with IBM at the level of billion-dollar revenues. From there, vision stepped up to the 10X Imperative, a quality-improvement program that focused on arbitrary goals and measures that were, in fact, beyond the company's control. The last escalation came when Mentor Graphics decided to Change the Way the World Designs. The company had stopped making product and was making poetry. Finally, in 1991, after six years of increasing self-infatuation, Mentor hit a wall of decreasing indicators. Langeler, who had long since begun to doubt the value of abstract visions, reinstated Build Something People Will Buy. And Mentor was back to basics, a sense of purpose back to its workplace. PMID:10117368

Langeler, G H



Vision Systems Design  

NSDL National Science Digital Library

Vision Systems Design is a magazine that provides comprehensive information and analyses about "machine-vision and imaging components, boards, assemblies, software, and systems." Its online version is free and has many Web-exclusive features available. For example, Back to Basics is a series of technical articles about a certain topic; the February 2003 issue has articles on FireWire interfaces, infrared systems used to increase vehicle safety, and much more. Technology news and industry trends are also provided online.



Synthetic Vision Systems  

NASA Technical Reports Server (NTRS)

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.

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



Developmentally cognitive robot vision  

Microsoft Academic Search

A generic methodology for designing developmental cognitive robot vision systems was proposed to add development capability to cognitive vision systems. Four issues were discussed: (1) human-like architecture suitable for different visual purposes, (2) efficient memory organization, forming, and indexing mechanism proper for emergence of machine imagery and experience-based learning, (3) life-like development model for open-ended cognitive improvement and perception development,

Tao Jiang; Fuchun Sun; Xingzhou Jiang



Palette-colouring: a belief propagation approach  

NASA Astrophysics Data System (ADS)

We consider a variation of the prototype combinatorial optimization problem known as graph colouring. Our optimization goal is to colour the vertices of a graph with a fixed number of colours, in a way to maximize the number of different colours present in the set of nearest neighbours of each given vertex. This problem, which we pictorially call palette-colouring, has been recently addressed as a basic example of a problem arising in the context of distributed data storage. Even though it has not been proved to be NP-complete, random search algorithms find the problem hard to solve. Heuristics based on a naive belief propagation algorithm are observed to work quite well in certain conditions. In this paper, we build upon the mentioned result, working out the correct belief propagation algorithm, which needs to take into account the many-body nature of the constraints present in this problem. This method improves the naive belief propagation approach at the cost of increased computational effort. We also investigate the emergence of a satisfiable-to-unsatisfiable 'phase transition' as a function of the vertex mean degree, for different ensembles of sparse random graphs in the large size ('thermodynamic') limit.

Pelizzola, Alessandro; Pretti, Marco; van Mourik, Jort



CMSC 426: Image Processing (Computer Vision)  

E-print Network

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

Jacobs, David


Kinetic movement analysis in adults with vision loss.  


The purpose of this investigation was to assess movement capabilities of adults with visual impairments in comparison to sighted peers. Thirty participants (n = 15 visually impaired; n = 15 without vision loss) were age and gender matched and assessed on three functional movement measures. A Walk Across, Forward Lunge, and Sit to Stand were completed on a long force plate and analyzed using Group MANOVAs. Individuals with visual impairment were more cautious and conservative in their movement as evident by significantly reduced performance on both the Walk Across assessment and the Forward Lunge task. Performance between groups was similar on the Sit to Stand maneuver. It was concluded that individuals with visual impairments are more cautious and have more difficulty performing tasks when their center of gravity is outside of their base of support. PMID:17916917

Ray, Christopher; Horvat, Michael; Williams, Michael; Blasch, Bruce



Photonic-crystal full-colour displays  

NASA Astrophysics Data System (ADS)

In our information-rich world, it is becoming increasingly important to develop technologies capable of displaying dynamic and changeable data, for reasons ranging from value-added advertising to environmental sustainability. There is an intense drive at the moment towards paper-like displays, devices having a high reflectivity and contrast to provide viewability in a variety of environments, particularly in sunlight where emissive or backlit devices perform very poorly. The list of possible technologies is extensive, including electrophoretic, cholesteric liquid crystalline, electrochromic, electrodewetting, interferometric and more. Despite tremendous advances, the key drawback of all these existing display options relates to colour. As soon as an RGB (red, green and blue) colour filter or spatially modulated colour scheme is implemented, substantial light losses are inevitable even if the intrinsic reflectivity of the material is very good.

Arsenault, André C.; Puzzo, Daniel P.; Manners, Ian; Ozin, Geoffrey A.



Multi-colour detection of gravitational arcs  

NASA Astrophysics Data System (ADS)

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.

Maturi, Matteo; Mizera, Sebastian; Seidel, Gregor



Coloured marking inside glass by laser radiation  

NASA Astrophysics Data System (ADS)

Laser labelling inside glass induces micro-cracks by high energy densities in the focus. The micro-cracks reduce the mechanical stability of glass. Light scattering allows the observer to perceive the cracks as white pixels. Coloured marking of glass in this manner is not possible. Coloured marking inside glass by changing the oxidation state of the metal ions locally in the focus does not weaken the mechanical properties of the glass. Two kind of glass systems, lime-natron-silicate and borosilicate with 0.5 % mass-content of doping are investigated. The simultaneous presence of donators and acceptors allows a transition of electrons between polyvalent ions, and can lead to permanent colour-centres inside the glass, due to the fact that the absorption of the polyvalent ions is changed by the laser-induced conversion process. For this purpose a 3 ? Nd:YAG (wavelength ?L = 355 nm, pulse duration t = 10 to 80 ns) and a Ti:Sapphire solid-state laser (wavelength ?L = 810 nm, pulse duration t = 200 fs) are used. The radiation parameters and the chemical composition of the glass (mainly doping) are the dominant factors to generate coloured marking. The transmittance as a function of the fluence and the change of the absorption coefficient is measured and gives a statement of the colourshade. Further the difference between lime-natron-silicate and borosilicate glass (same doping variety) is examined. Actually mauve, yellow, red-brown an grey colouring can be produced. Cracks in the microstructure of glass can also be the cause for brown colour-centres generating.

Ligbado, Grace; Horn, Alexander; Kreutz, Ernst W.; Krauss, Manfred M.; Siedow, Norbert; Hensel, Hartmut



Measuring the colour of rendering mortars  

NASA Astrophysics Data System (ADS)

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.

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



The Relationship of Cognitive Style Variables to Optimal Test Performance in Hearing-Impaired Children.  

ERIC Educational Resources Information Center

The relationship of cognitive style variables and conditions of test administration was investigated in cognitive assessments of hearing-impaired children, aged six through eleven. One hundred-twenty children were given the Raven Coloured Progressive Matrices (CPM) and a Piagetian battery under one of six conditions of testing: (1) standard; (2)…

Dillon, Ronna F.


Colour-temperature correspondences: when reactions to thermal stimuli are influenced by colour.  


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

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



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

PubMed Central

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

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



Colour-the-INSight: combining a direct view rifle sight with fused intensified and thermal imagery  

NASA Astrophysics Data System (ADS)

We present the design and evaluation of a new demonstrator rifle sight viewing system containing direct view, red aim point and fusion of an (uncooled, LWIR) thermal sensor with a digital image intensifier. Our goal is to create a system that performs well under a wide variety of (weather) conditions during daytime and nighttime and combines the advantages of the various sensor systems. A real-time colour image with salient hot targets is obtained from the night vision sensors by implementing the Colour-the-Night fusion method (Hogervorst & Toet, 2010) on the on-board processor. The prototype system was evaluated in a series of field trials with military observers performing detection and identification tasks. The tests showed that during daytime the addition of a thermal image to direct vision is advantageous, e.g. for the detection of hot targets. At nighttime, the fusion of thermal and image intensified imagery results in increased situational awareness and improved detection of (hot) targets. For identification of small (handheld) objects, the technology needs to be further refined.

Hogervorst, M. A.; Jansen, C.; Toet, A.; Bijl, P.; Bakker, P.; Hiddema, A. C.; van Vliet, S. F.



Obtaining Online Ecological Colourings by Generalizing First-Fit  

NASA Astrophysics Data System (ADS)

A colouring of a graph is ecological if every pair of vertices that have the same set of colours in their neighbourhood are coloured alike. We consider the following problem: if a graph G and an ecological colouring c of G are given, can further vertices added to G, one at a time, be coloured using colours from some finite set C so that at each stage the current graph is ecologically coloured? If the answer is yes, then we say that the pair (G,c) is ecologically online extendible. By generalizing the well-known First-Fit algorithm, we are able to characterize when (G,c) is ecologically online extendible. For the case where c is a colouring of G in which each vertex is coloured distinctly, we give a simple characterization of when (G,c) is ecologically online extendible using only the colours of c, and we also show that (G,c) is always online extendible if we permit ourselves to use one extra colour. We also study (off-line) ecological H-colourings where the colouring must satisfy further restrictions imposed by some fixed pattern graph H. We characterize the computational complexity of this problem. This solves an open question posed by Crescenzi et al.

Johnson, Matthew; Patel, Viresh; Paulusma, Daniël; Trunck, Théophile


Assessment of novel binocular colour, motion and contrast tests in glaucoma.  


The effects of glaucoma on binocular visual sensitivity for the detection of various stimulus attributes are investigated at the fovea and in four paracentral retinal regions. The study employed a number of visual stimuli designed to isolate the processing of various stimulus attributes. We measured absolute contrast detection thresholds and functional contrast sensitivity by using Landolt ring stimuli. This psychophysical Landolt C-based contrast test of detection and gap discrimination allowed us to test parafoveally at 6 ° from fixation and foveally by employing interleaved testing locations. First-order motion perception was examined by using moving stimuli embedded in static luminance contrast noise. Red/green (RG) and yellow/blue (YB) colour thresholds were measured with the Colour Assessment and Diagnosis (CAD) test, which utilises random dynamic luminance contrast noise (± 45 %) to ensure that only colour and not luminance signals are available for target detection. Subjects were normal controls (n = 65) and glaucoma patients with binocular visual field defects (n = 15) classified based on their Humphrey Field Analyzer mean deviation (MD) scores. The impairment of visual function varied depending on the stimulus attribute and location tested. Progression of loss was noted for all tests as the degree of glaucoma increased. For subjects with mild glaucoma (MD -0.01 dB to -6.00 dB) significantly more data points fell outside the normal age-representative range for RG colour thresholds than for any other visual test, followed by motion thresholds. This was particularly the case for the parafoveal data compared with the foveal data. Thus, a multifaceted measure of binocular visual performance, incorporating RG colour and motion test at multiple locations, might provide a better index for comparison with quality of life measures in glaucoma. PMID:23812834

Rauscher, Franziska G; Chisholm, Catharine M; Edgar, David F; Barbur, John L



Why Cyclops could not compete with Ulysses: monocular vision and mental images.  


The present research demonstrates that the limitations of congenitally blind people in tasks requiring the processing of mental images are specifically related to the absence of binocular vision and not to the absence of vision per se. We contrasted three different groups of participants: sighted; visually impaired, with reduced binocular vision; monocular, with a normal visual acuity although in one eye only. Visually impaired participants (i.e. blurred vision) show a pattern of performance comparable to that of the sighted. In contrast, monocular participants show a similar pattern of performance to congenitally blind individuals despite being able to see perfectly well. These results shed new light on the relationship between perception and imagery and on the characteristics of sequential and simultaneous processes in the human brain. PMID:16641676

Vecchi, Tomaso; Cattaneo, Zaira; Monegato, Maura; Pece, Alfredo; Cornoldi, Cesare; Pietrini, Pietro



Strategies for eye positioning after laser-related loss of central vision  

NASA Astrophysics Data System (ADS)

Loss of foveal vision from exposure to laser light or retinal disease can seriously impair visual functions like reading and visual search. Central scotomas produce large losses in visually guided performance because central vision has the best visual resolution, compared to more peripheral retina, and is also important in the normal reflexive patten of eye movement. Relatively small central field scotomas can produce significant impairments in visual search if tasks require a high degree of foveal vision such as seeing fine detail or discriminating similar contours or letters. Subjects faced with the task of adapting to the loss of ventral vision sometimes position their eyes in ways which are either asymmetrical, not optimum, or seem to generate abnormal eye movements, even after extensive practice. Discussion includes oculomotor drift, error fixations, hyper-eccentric fixations and remedial eye positioning strategies.

Bertera, J. H.



Impact of Cataract Surgery in Reducing Visual Impairment: A Review  

PubMed Central

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

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



VisionBlocks: A Social Computer Vision Framework  

E-print Network

Vision Blocks ( 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 ...

Bendale, Abhijit


ORIGINAL PAPER Seasonal ontogenetic colour plasticity in the adult striated  

E-print Network

February 2008 # Springer-Verlag 2008 Abstract Camouflage and warning colouration are two important forms provides a benefit of increased camouflage. Keywords Aposematism . Conspicuousness . Camouflage . Crypsis animals: cryptic colouration or camouflage, which decreases the risk of detection, and warning

Tullberg, Birgitta


Introduction With the exception of bioluminescence, animal colour pat-  

E-print Network

iridescent colouration of male damselflies is determined by variation in surface nanostructures (cuticular that are stunningly bright and iridescent in their appearance, yet functionally obscure. These colours are often

Macedonia, Joseph


Whorfian effects on colour memory are not reliable.  


The Whorfian hypothesis suggests that differences between languages cause differences in cognitive processes. Support for this idea comes from studies that find that patterns of colour memory errors made by speakers of different languages align with differences in colour lexicons. The current study provides a large-scale investigation of the relationship between colour language and colour memory, adopting a cross-linguistic and developmental approach. Colour memory on a delayed matching-to-sample (XAB) task was investigated in 2 language groups with differing colour lexicons, for 3 developmental stages and 2 regions of colour space. Analyses used a Bayesian technique to provide simultaneous assessment of two competing hypotheses (H1-Whorfian effect present, H0-Whorfian effect absent). Results of the analyses consistently favoured H0. The findings suggest that Whorfian effects on colour memory are not reliable and that the importance of such effects should not be overestimated. PMID:25230782

Wright, Oliver; Davies, Ian R L; Franklin, Anna



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

NASA Astrophysics Data System (ADS)

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.

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



Mobile assistive technologies for the visually impaired.  


There are around 285 million visually impaired people worldwide, and around 370,000 people are registered as blind or partially sighted in the UK. Ongoing advances in information technology (IT) are increasing the scope for IT-based mobile assistive technologies to facilitate the independence, safety, and improved quality of life of the visually impaired. Research is being directed at making mobile phones and other handheld devices accessible via our haptic (touch) and audio sensory channels. We review research and innovation within the field of mobile assistive technology for the visually impaired and, in so doing, highlight the need for successful collaboration between clinical expertise, computer science, and domain users to realize fully the potential benefits of such technologies. We initially reflect on research that has been conducted to make mobile phones more accessible to people with vision loss. We then discuss innovative assistive applications designed for the visually impaired that are either delivered via mainstream devices and can be used while in motion (e.g., mobile phones) or are embedded within an environment that may be in motion (e.g., public transport) or within which the user may be in motion (e.g., smart homes). PMID:24054999

Hakobyan, Lilit; Lumsden, Jo; O'Sullivan, Dympna; Bartlett, Hannah



Supersymmetric coloured/hairy black holes  

NASA Astrophysics Data System (ADS)

We discuss all possible spherically symmetric black hole type solutions to an N = 2 supergravity model with SO (3) gauging. The solutions consist of a one parameter family of black hole solutions evading the no-hair theorem and an isolated solution that is a supersymmetric analogue of a coloured black hole.

Meessen, Patrick



Computer analysis of Van Gogh's complementary colours  

Microsoft Academic Search

Traditionally, the analysis of visual arts is performed by human art experts only. The availability of advanced artificial intelligence techniques makes it possible to support art experts in their judgement of visual art. In this article currently available image-analysis techniques are applied. Our aim is (1) to determine how successful the usage of complementary colours was in the oeuvre of

Igor Berezhnoy; Eric O. Postma; H. Jaap Van Den Herik



How feather colour reflects its carotenoid content  

Microsoft Academic Search

Summary 1. Many birds sequester carotenoid pigments in colourful patches of feathers to advertise or compete for mates. Because carotenoids can be scarce in nature and serve valuable physiological functions, only the highest-quality individuals are thought to acquire or allocate more pigments for use in sexual displays. 2. A critical but rarely tested assumption of carotenoid-based signals is that the

Lauri Saks; Kevin McGraw; Peeter Horak



All the colours of the rainbow  

NASA Astrophysics Data System (ADS)

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?

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



Overview of sports vision  

NASA Astrophysics Data System (ADS)

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).

Moore, Linda A.; Ferreira, Jannie T.



What weta want: colour preferences of a frugivorous insect  

Microsoft Academic Search

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,

Nik Fadzly; K. C. Burns



Time Optimal d-List Colouring of a Graph  

NASA Astrophysics Data System (ADS)

We present the first linear time algorithm for d-list colouring of a graph - i.e. a proper colouring of each vertex v by colours coming from lists L(v) of sizes at least deg(v). Previously, procedures with such complexity were only known for ?-list colouring, where for each vertex v one has |L(v)|??, the maximum of the vertex degrees. An implementation of the procedure is available.

Gravin, Nick


Depression in Cognitive Impairment  

PubMed Central

Depression and cognitive disorders, including dementia and mild cognitive impairment, are common in the elderly. Depression is also a common feature of cognitive impairment although the symptoms of depression in cognitive impairment differ from depression without cognitive impairment. Pre-morbid depression approximately doubles the risk of subsequent dementia. There are two predominant, though not mutually exclusive, constructs linking pre-morbid depression to subsequent cognitive impairment: Alzheimer’s pathology and the vascular depression hypothesis. When evaluating a patient with depression and cognitive impairment, it is important to obtain caregiver input and to evaluate for alternative etiologies for depressive symptoms such as delirium. We recommend a sequential approach to the treatment of depression in dementia patients: (1) a period of watchful waiting for milder symptoms, (2) psychosocial treatment program, (3) a medication trial for more severe symptoms or failure of psychosocial interventions, and (4) possible ECT for refractory symptoms. PMID:23933974

Pellegrino, Laurel D.; Lyketsos, Constantine G.; Marano, Christopher M.



Grounding Our Vision: Brain Research and Strategic Vision  

ERIC Educational Resources Information Center

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…

Walker, Mike



Bio-inspired vision  

NASA Astrophysics Data System (ADS)

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.

Posch, C.



The impact of vision loss on postural stability and balance strategies in individuals with profound vision loss.  


Individuals with vision loss are at an increased risk of falls. Understanding what factors contribute to postural instability within this population is a necessary step towards the development of physiotherapeutic programs targeted at reduction of falls within this population. Forty-six age-matched participants were evaluated with the sensory organization test (SOT) on a NeuroCom Equitest. The conditions provided accurate and inaccurate sensory information to test the participants' ability to utilize the correct information to maintain postural stability. A one-way analysis of variance was performed on composite balance scores between groups. Based on the data analysis, significant differences were apparent in equilibrium composite scores (P<.05) and strategy utilized to maintain postural stability between the visually impaired and sighted sample. Results indicate that restricted vision has a negative impact on overall postural stability and visually impaired individuals utilize greater use of hip strategy to maintain postural stability. PMID:18023185

Ray, Christopher T; Horvat, Michael; Croce, Ronald; Mason, R Christopher; Wolf, Steven L



Perception of colour in unilateral tritanopia.  

PubMed Central

The unilateral tritanope described in the previous paper (Alpern, Kitahara & Krantz, 1983) was able to match every narrow-band light presented to his tritanopic eye with lights from a tristimulus colorimeter viewed in the adjacent field by the normal eye. In two regions of the spectrum (called isochromes) physically identical lights appeared identical to the observer's two eyes. One isochrome was close to 'blue' for the normal eye, the other was in the long-wave spectral region seen by the normal eye predominantly as 'red'. Between these isochromes the normal eye required less than spectral purity to match, dropping to near zero purity at 560-570 nm. A mixture of the two isochromes that appeared purple to the normal eye appeared neutral to the tritanopic eye. Hence dichoptic matches grossly violate Grassmann's additivity law. For the normal eye colour naming conformed to typical normal results. For the tritanopic eye the results were coherent with those found by dichoptic matching: the spectrum was divided into two regions by the achromatic neutral band. To the short-wave side, only the colour names 'blue' and 'white' were ever used. To the long-wave side the predominant colour names were 'red' and 'white' with some 'yellow'. Spectral lights appeared neither 'red-blue' nor greenish. Surrounding the test with an annulus either 430 nm, 650 nm, or a mixture of these, fails to induce any greenish appearance, although the achromatic band shifted in the expected directions. It is concluded that there must be exactly three functionally independent, essentially non-linear central codes for colour perception, and that these codes are different from those suggested in existing theories of colour perception. PMID:6603509

Alpern, M; Kitahara, K; Krantz, D H



Robotics Peripheral Vision  

NSDL National Science Digital Library

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.

Vu Bioengineering Ret Program


Night Vision Camera  

NASA Technical Reports Server (NTRS)

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.



On the colour-colour properties of the Extremely Red Objects  

NASA Astrophysics Data System (ADS)

The colours of the galaxy class known as Extremely Red Objects (EROs; R-K>5) are considered to be consistent with two distinct galaxy populations at high redshift: evolved ellipticals or young dusty starbursts. In this paper the properties of EROs, spanned by the five photometric bands RIJHK, are investigated as to the possibility to distinguish between these two galaxy populations using only broad band photometry. The broad band colours of elliptical and starburst galaxies at redshifts up to 5 are computed from synthetic spectra obtained using the spectral evolution synthesis programme PÉGASE.2. Two initial mass functions and a range of metallicities and extinctions are used. In order to be extremely red in the redshift range considered, the evolution of the R-K colour sets the requirement that ellipticals have to be less than 7-8 Gyr old, and that the starbursts must have colour excesses of E(B-V)>1, as derived from the nebular emission lines. In investigating the overlap in the different colour-colour planes as a function of redshift, it is found that the planes formed from permutations of the same three filters exhibit very similar overlap characteristics. In colour-colour planes formed within such triplets one of the filters will serve as a ``pivot'' band against which the two other bands are compared. The configuration where this pivot band lies between the other two bands has the best performance as a discriminator among the three possible configurations. A consistent behaviour cannot be found among the configurations formed by permuting four filters. The minimal filter configuration R-H vs. H-K is found to be the very best discriminator, working as such up to redshift 2.9.

Bergström, S.; Wiklind, T.



Analytical method for determining colour intensities based on Cherenkov radiation colour Quenching  

Microsoft Academic Search

In the present work a study was made for determining colour intensities using as luminous non-monochromatic source the Cherenkov\\u000a emission produced in the walls of a glass capillary which acts as luminous source itself inside of a coloured solution to\\u000a be evaluated. The reproducibility of this method has been compared with the spectrophotometric assay; the relative errors\\u000a of both analytical

C. González-Gómez; J. de D. López-González; M. A. Ferro-García



Analysis of organic colouring and binding components in colour layer of art works  

Microsoft Academic Search

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

S. Kuckova; I. Nemec; R. Hynek; J. Hradilova; T. Grygar



Then and now: James Clerk Maxwell and colour  

Microsoft Academic Search

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

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



Colour image retrieval based on DCT-domain vector quantisation  

E-print Network

Colour image retrieval based on DCT-domain vector quantisation index histograms Z.-M. Lu and H. Burkhardt A new kind of feature for colour image retrieval based on DCT-domain vector quantisation (VQ for each colour component) are calculated from 12 DCT-VQ index sequences, respectively. The retrieval


Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health  

Microsoft Academic Search

Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated,

Ian D. Stephen; Vinet Coetzee; Miriam Law Smith; David I. Perrett



Inheritance of coat colour in the field spaniel dog  

E-print Network

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

Paris-Sud XI, Université de


they form juxtaposed pointillistic colour centres which, to our  

E-print Network

EX4 4QL, UK. E-mail: The nature of Drosophila melanogaster C.J. Reaume and M their wing colours and patterns. We seek to know how changes in genes and development can control colour weighting of inter-specific and intra-specific selection pressures affect wing colour intensity, hue

Sokolowski, Marla


The chemistry and analysis of annatto food colouring: a review  

Microsoft Academic Search

Annatto food colouring (E160b) has a long history of use in the food industry for the colouring of a wide range of food commodities. The principal colouring component of annatto is the oil-soluble diapo carotenoid bixin, which is the methyl ester of the dicarboxylic acid norbixin and soluble in aqueous alkali. Bixin and norbixin, therefore, exhibit not only physicochemical properties

M. Scotter



Performance Characterization of Clustering Algorithms for Colour Image Segmentation  

E-print Network

Performance Characterization of Clustering Algorithms for Colour Image Segmentation Dana Elena Ilea to extract the colour information that is used in the image segmentation process. The aim of this paper on a large suite of mosaic images. Index terms: Colour image segmentation, Fuzzy clustering, Competitive

Whelan, Paul F.


An Interaction of Screen Colour and Lesson Task in CAL  

ERIC Educational Resources Information Center

Colour is a common feature in computer-aided learning (CAL), though the instructional effects of screen colour are not well understood. This investigation considers the effects of different CAL study tasks with feedback on posttest performance and on posttest memory of the lesson colour scheme. Graduate students (n=68) completed a computer-based…

Clariana, Roy B.



The Proportional Colouring Problem: Optimizing Buffers in Wireless Mesh Networks  

E-print Network

The Proportional Colouring Problem: Optimizing Buffers in Wireless Mesh Networks Florian Huc 1 I3S optimization: the proportional edge colouring problem. Given a graph G with positive weights associated to its edges, we want to find a proper edge colouring which assigns to each edge at least a proportion (given

Paris-Sud XI, Université de


Balanced colourings of strongly regular R. A. Bailey  

E-print Network

Balanced colourings of strongly regular graphs R. A. Bailey School of Mathematical Sciences, Queen is balanced if every pair of distinct colours occurs equally often on the ends of an edge. When the graph is the complete regular multipartite graph a balanced colouring is just a balanced incomplete-block design, or 2

Queen Mary, University of London


Do You Have Low Vision?  


... at NEI Education Programs Training and Jobs Healthy Vision Diabetes Diabetes Home How Much Do You Know? ... hablarle a su oculista Do You Have Low Vision? Listen There are many signs that can signal ...


Contact Lenses for Vision Correction  


... Eye Health News Consumer Alerts Contact Lenses for Vision Correction Tweet What are contacts? Contact lenses are ... on the surface of the eye. They correct vision like eyeglasses do and are safe when used ...


Computational Vision: A Critical Review  

E-print Network

We review the progress made in computational vision, as represented by Marr's approach, in the last fifteen years. First, we briefly outline computational theories developed for low, middle and high-level vision. We ...

Edelman, Shimon



Epidemiological aspects of visual impairment above 50 years in a rural area.  


A cross-sectional survey was conducted in 5 villages in central India to find out the extent, causes and epidemiological factors for visual impairment among 903 individuals aged above 50 years; 44.3% of them were visually impaired (29.4% with low vision and 14.9% blind). Age-specific visual impairment increased at a rate of 13.2% with each decade of advancing age. Landless labourers suffered more from visual impairment than other occupational groups (p < 0.05). Socioeconomic and literacy status of the population did not significantly influence the prevalence of visual impairment. Major causes of visual impairment were cataract (48.5%), refractive errors (24.5%), age-related macular degeneration (10%), glaucoma (6.8%), and others (10.2%). In view of the high prevalence of visual impairment among the elderly individuals, it is necessary to intensify our efforts in motivating them for early detection and treatment. PMID:7890940

Singh, M C; Murthy, G V; Venkatraman, R; Nayar, S



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

PubMed Central

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



A versatile optoelectronic aid for low vision patients.  


The purpose of this work is to describe a versatile optoelectronic aid for low vision rehabilitation based on reconfigurable hardware. This aid is easily adaptable to diverse pathologies (with different associated processing tasks) and to the progression of the visual impairment. This platform has a mobile configuration that uses a see-through head-mounted display (Nomad). We have implemented different types of vision enhancement on this versatile platform, and briefly summarize here their computational costs (in terms of hardware resource requirements). We have evaluated two representative capabilities of this aid (Augmented View and digital zoom) with measurements of visual acuity, contrast sensitivity and visual field. We have tested the Nomad head-mounted display and the Augmented View modality, in eight subjects with retinitis pigmentosa: the digital zoom was tested in six low vision subjects and nine normally-sighted subjects. We show that the Nomad display with Augmented View configuration does not impair the residual vision; and that there is an increase in visual acuity (VA) with the digital zoom configuration. The major advantage of this platform is that it can easily embed different image processing tasks and since it is based on a FPGA device, it can be specifically configured to tasks requiring real-time processing. PMID:19689551

Peláez-Coca, María Dolores; Vargas-Martín, Fernando; Mota, Sonia; Díaz, Javier; Ros-Vidal, Eduardo



Peripheral vision benefits spatial learning by guiding eye movements.  


The loss of peripheral vision impairs spatial learning and navigation. However, the mechanisms underlying these impairments remain poorly understood. One advantage of having peripheral vision is that objects in an environment are easily detected and readily foveated via eye movements. The present study examined this potential benefit of peripheral vision by investigating whether competent performance in spatial learning requires effective eye movements. In Experiment 1, participants learned room-sized spatial layouts with or without restriction on direct eye movements to objects. Eye movements were restricted by having participants view the objects through small apertures in front of their eyes. Results showed that impeding effective eye movements made subsequent retrieval of spatial memory slower and less accurate. The small apertures also occluded much of the environmental surroundings, but the importance of this kind of occlusion was ruled out in Experiment 2 by showing that participants exhibited intact learning of the same spatial layouts when luminescent objects were viewed in an otherwise dark room. Together, these findings suggest that one of the roles of peripheral vision in spatial learning is to guide eye movements, highlighting the importance of spatial information derived from eye movements for learning environmental layouts. PMID:22930007

Yamamoto, Naohide; Philbeck, John W



Emotion-induced trade-offs in spatiotemporal vision.  


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 vision at the expense of fine-grained spatial vision. We tested participants' threshold resolution with Landolt circles containing a small spatial or brief temporal discontinuity. The prior presentation of a fearful face cue, compared with a neutral face cue, impaired spatial resolution but improved temporal resolution. In addition, we show that these benefits and deficits were triggered selectively by the global configural properties of the faces, which were transmitted only through low spatial frequencies. Critically, the common locus of these opposite effects suggests a trade-off between magno- and parvocellular-type visual channels, which contradicts the common assumption that emotion invariably improves vision. We show that, rather than being a general "boost" for all visual features, affective neural circuits sacrifice the slower processing of small details for a coarser but faster visual signal. PMID:21443382

Bocanegra, Bruno R; Zeelenberg, René



Vision for a smart kiosk  

Microsoft Academic Search

We describe a novel computer vision application: vision- based human sensing for a Smart Kiosk interface. A Smart Kiosk is a free-standing information dispensing computer appliance capable of engaging in public interactions with multiple people. Vision sensing is a critical component of the kiosk interface, where it is used to determine the context for the interaction. We present a taxonomy

James M. Rehg; Maria Loughlin; Keith Waters



Vision for a UAV helicopter  

Microsoft Academic Search

This paper presents and overview of the basic and applied research carried out by the Computer Vision Laboratory, Linkoping University, in the WITAS UAV Project. This work includes customizing and redesigning vision methods to t the particular needs and restrictions imposed by the UAV platform, e.g., for low-level vision, motion estimation, navigation, and tracking. It also includes a new learning

Klas Nordberg; Gunnar Farneback; Gosta Granlund; Anders Moe; Johan Wiklund


Purposive and qualitative active vision  

Microsoft Academic Search

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

J. Aloimonos




E-print Network

CORRESPONDENCE PROBLEMS IN GEOMETRIC VISION OLOF ENQVIST Faculty of Engineering CentreTryck, Lund 2009 #12;Preface This thesis concerns optimal methods for geometric vision problems. Two important and branch and bound to handle the correspon- dence problems arising in geometric vision. The thesis consists

Lunds Universitet


Vision Screening For Head Starters.  

ERIC Educational Resources Information Center

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,…

Foley, Celia


Clinical Trials in Vision Research  

E-print Network

Clinical Trials in Vision Research Information for Volunteers U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Eye Institute #12;Clinical trials in vision Trials in Vision Research 1 Basics of Clinical Trials 3 How a Clinical Trial is Conducted 7 Participating

Bandettini, Peter A.


Structured Prediction in Computer Vision  

E-print Network

Structured Prediction in Computer Vision Tiberio Caetano and Richard Hartley NICTA Tiberio Caetano and Richard Hartley: Structured Prediction in Computer Vision 1 / 71 nicta-logo #12;ThanksAuley, Yu, NIPS '09 Tiberio Caetano and Richard Hartley: Structured Prediction in Computer Vision 2 / 71

Caetano, Tiberio


Representation or context as a cognitive strategy in colour constancy?  


If an identification task with colour constancy as its objective is carried out under drastically changing illumination, do people rely mainly on colour information or do they rely on other sources of information? This question suggested two hypotheses for testing: (i) context hypothesis: people rely mainly on colour information (spectral reflectance or illumination chromaticity) to achieve colour constancy; (ii) representation hypothesis: people rely mainly on all other clues associated with colour to achieve colour constancy, including form information (any shape elements) and space information (spatial coordinates or spatial correlation). Experiment 1 showed that form information was readily associated with colour information to produce implicit representation. This gave the best colour-constancy performance (95.72%) and the fastest processing speed, so it probably used a top-down process. However, it was also prone to error owing to assumptions. Space information was not readily associated with colour information so colour-constancy performance was halved (48.73%) and processing time doubled. When the subject was deprived of both information sources and only given colour information, this resulted in the longest reaction times and the worst colour-constancy performance (41.38%). These results clearly support the representation hypothesis rather than the context hypothesis. When all three clues were available at the same time, the order of preference was: symbol, location, then colour. Experiment 2 showed that when form information was the main clue, colour-constancy performance was conceptually driven and processed more quickly; this supports the representation hypothesis. However, when form information was not used, colour constancy was data-driven, processed more slowly, and achieved an inferior identification rate overall; this supports the context hypothesis. PMID:18986062

Lin, Ta-Wei; Sun, Chun-Wang



The coding of uniform colour figures in monkey visual cortex  

PubMed Central

Psychophysical studies indicate that perception of the colour and brightness of a surface depends on neural signals evoked by the borders of the surface rather than its interior. The visual cortex emphasizes contrast borders, but it is unclear whether colour surface signals also exist, whether colour border signals are orientation selective or mainly non-oriented, and whether cortical processing tends to separate colour and form information. To address these questions we examined the representation of uniform colour figures by recording single neuron activity from areas V1 and V2 in alert macaque monkeys during behaviourally induced fixation. Three aspects of coding were quantified: colour, orientation and edge selectivity. The occurrence of colour selectivity was not correlated with orientation or edge selectivity. The fraction of colour-selective cells was the same (64 % in layers 2 and 3 of V1, 45 % in V2) for oriented and non-oriented cells, and for edge-selective and surface-responsive cells. Oriented cells were often highly selective in colour space, and about 40 % of them were selective for edge polarity or border ownership. Thus, contrary to the idea of feature maps, colour, orientation and edge polarity are multiplexed in cortical signals. The results from V2 were similar to those from upper-layer V1, indicating that cortical processing does not strive to separate form and colour information. Oriented cells were five times more frequent than non-oriented cells. Thus, the vast majority of colour-coded cells are orientation tuned. Based on response profiles across a 4 deg square figure, and the relative frequency of oriented and non-oriented cells, we estimate that the cortical colour signal is 5–6 times stronger for the edges than for the surface of the figure. The frequency of oriented colour cells and their ability to code edge polarity indicate that these cells play a major role in the representation of surface colour. PMID:12611925

Friedman, Howard S; Zhou, Hong; von der Heydt, Rüdiger



Colour and Optical Properties of Materials: An Exploration of the Relationship Between Light, the Optical Properties of Materials and Colour  

Microsoft Academic Search

Colour is an important and integral part of everyday life, and an understanding and knowledge of the scientific principles behind colour, with its many applications and uses, is becoming increasingly important to a wide range of academic disciplines, from physical, medical and biological sciences through to the arts. Colour and the Optical Properties of Materials carefully introduces the science behind

Richard J. D. Tilley



Determinants of social participation of visually impaired older adults  

Microsoft Academic Search

Purpose  To assess determinants of social participation among visually impaired older adults.\\u000a \\u000a \\u000a \\u000a Methods  This cross-sectional study included visually impaired persons (?55 years; n = 173) who were referred to a low-vision rehabilitation center. Determinants (i.e., sociodemographic, physical, social and\\u000a psychological factors, and personal values) of participation were identified in four domains of participation: (1) domestic\\u000a life; (2) interpersonal interactions and relationships; (3) major life areas;

Manna A. AlmaSijrike; Sijrike F. Van der Mei; Johan W. Groothoff; Theo P. B. M. Suurmeijer


Dance: Verities, Values, Visions.  

ERIC Educational Resources Information Center

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…

Boorman, Joyce, Ed.; Harris, Dorothy, Ed.


Computer Vision Systems  

NASA Astrophysics Data System (ADS)

Food quality is of paramount consideration for all consumers, and its importance is perhaps only second to food safety. By some definition, food safety is also incorporated into the broad categorization of food quality. Hence, the need for careful and accurate evaluation of food quality is at the forefront of research and development both in the academia and industry. Among the many available methods for food quality evaluation, computer vision has proven to be the most powerful, especially for nondestructively extracting and quantifying many features that have direct relevance to food quality assessment and control. Furthermore, computer vision systems serve to rapidly evaluate the most readily observable foods quality attributes - the external characteristics such as color, shape, size, surface texture etc. In addition, it is now possible, using advanced computer vision technologies, to “see” inside a food product and/or package to examine important quality attributes ordinarily unavailable to human evaluators. With rapid advances in electronic hardware and other associated imaging technologies, the cost-effectiveness and speed of computer vision systems have greatly improved and many practical systems are already in place in the food industry.

Gunasekaran, Sundaram


A focus on vision.  


Eye problems, in general, tend to get overlooked in a crowd of broader health issues such as heart disease and cancer. For this reason, the vision health care community has been working hard in recent years to emphasize the importance of proper eye care. PMID:17243282

Rados, Carol



Peripheral Vision Lab  

NSDL National Science Digital Library

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.



Vision as Adaptive Epistemology  

E-print Network

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.

Ignazio Licata



Writing for Night Vision  

NSDL National Science Digital Library

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.

Twin Cities Public Television, Inc.



Computer Vision Jana Kosecka  

E-print Network

Software MATLAB (with Image Processing toolbox) · Open CV library #12;Textbooks #12;Project Deadlines-formation process · Pinhole (perspective) imaging in most ancient civilizations. · Euclid, perspective projection, 4 · Vision as a sensor - medical imaging, Geospatial Imaging, robotics, visual surveillance, inspection #12

Kosecka, Jana


Home vision tests  


... spots. If you normally wear glasses for reading, wear them for this test. If you wear bifocals, look through the bottom ... wear glasses or contact lenses for distance vision, wear them for the test. Check each eye separately, first the right and ...


Synthetic Vision Workshop 2  

NASA Technical Reports Server (NTRS)

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.

Kramer, Lynda J. (Compiler)




ERIC Educational Resources Information Center




Vision as Bayesian Inference:Vision as Bayesian Inference: Analysis by Synthesis.Analysis by Synthesis.  

E-print Network

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

Haykin, Simon


Diagnosing synaesthesia with online colour pickers: maximising sensitivity and specificity.  


The most commonly used method for formally assessing grapheme-colour synaesthesia (i.e., experiencing colours in response to letter and/or number stimuli) involves selecting colours from a large colour palette on several occasions and measuring consistency of the colours selected. However, the ability to diagnose synaesthesia using this method depends on several factors that have not been directly contrasted. These include the type of colour space used (e.g., RGB, HSV, CIELUV, CIELAB) and different measures of consistency (e.g., city block and Euclidean distance in colour space). This study aims to find the most reliable way of diagnosing grapheme-colour synaesthesia based on maximising sensitivity (i.e., ability of a test to identify true synaesthetes) and specificity (i.e., ability of a test to identify true non-synaesthetes). We show, applying ROC (receiver operating characteristics) to binary classification of a large sample of self-declared synaesthetes and non-synaesthetes, that the consistency criterion (i.e., cut-off value) for diagnosing synaesthesia is considerably higher than the current standard in the field. We also show that methods based on perceptual CIELUV and CIELAB colour models (rather than RGB and HSV colour representations) and Euclidean distances offer an even greater sensitivity and specificity than most currently used measures. Together, these findings offer improved heuristics for the behavioural assessment of grapheme-colour synaesthesia. PMID:23458658

Rothen, Nicolas; Seth, Anil K; Witzel, Christoph; Ward, Jamie



Three-dimensional plasmonic stereoscopic prints in full colour  

NASA Astrophysics Data System (ADS)

Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

Goh, Xiao Ming; Zheng, Yihan; Tan, Shawn J.; Zhang, Lei; Kumar, Karthik; Qiu, Cheng-Wei; Yang, Joel K. W.



Extremal problems for colourings of uniform hypergraphs  

NASA Astrophysics Data System (ADS)

We study a classical problem (first posed by Erd?s) in the extremal theory of hypergraphs. According to Erd?s, a hypergraph possesses property B if its set of vertices admits a 2-colouring such that no edge of the hypergraph is monochromatic. The problem is to find the minimum m(n) of all m such that there is an n-uniform (each edge contains exactly n vertices) hypergraph with exactly m edges that does not possess property B. We consider more general problems (including the case of polychromatic colourings) and introduce a number of parametric properties of hypergraphs. We obtain estimates for analogues of m(n) for extremal problems on various classes of hypergraphs.

Shabanov, D. A.



Improving the Rainbow Attack by Reusing Colours  

NASA Astrophysics Data System (ADS)

Hashing or encrypting a key or a password is a vital part in most network security protocols. The most practical generic attack on such schemes is a time memory trade-off attack. Such an attack inverts any one-way function using a trade-off between memory and execution time. Existing techniques include the Hellman attack and the rainbow attack, where the latter uses different reduction functions ("colours") within a table.

Ågren, Martin; Johansson, Thomas; Hell, Martin


Floral colour signal increases short-range detectability of a sexually deceptive orchid to its bee pollinator.  


Orchids of the genus Ophrys are pollinated by males of solitary bees and wasps through sexual deception. The flowers mimic the behaviourally active compounds of the sex pheromone of receptive females and thus attract males that seek to copulate. Odour is the main attractant while visual stimuli have been assumed so far to play only a minor role. In contrast to most species of the genus, Heldreich's orchid Ophrys heldreichii, which is pollinated by males of the long-horned bee Tetralonia berlandi, possesses a bright pink perianth that appears conspicuous to a human observer. We investigated the role of this floral colour signal in pollinator attraction. We filmed approach flights of male bees to flowers in which we removed the original perianth and in which we substituted the perianth with an artificial one of a particular selected colour. At distances >30 cm, male search time correlated only with wind speed but not with the spectral parameters of the perianth, i.e. chromatic and green receptor-specific contrast. By contrast, in the close range (<30 cm), where the perianth subtends a visual angle of at least 5 deg. to the bee's eye, search time decreased with increasing green receptor contrast between perianth and background; however, no correlation with chromatic contrast or wind speed was found. Our results indicate that pollinators are first attracted by olfactory signals from a distance. Once in the vicinity of the flower where spatial vision of the males is sufficient, they are guided exclusively by vision. However, it can be expected that possession of a ;non-private' colour signal would increase the risk of pollen loss in sexually deceptive orchids by accidentally attracting non-specific flower visitors. We therefore discuss the occurrence of colour signals in the genus Ophrys in respect to the species-specific visual system of the pollinators. PMID:19376957

Streinzer, Martin; Paulus, Hannes F; Spaethe, Johannes



Impairment in Non-Word Repetition: A Marker for Language Impairment or Reading Impairment?  

ERIC Educational Resources Information Center

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…

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



Modeling of image perception and discrimination by the visually impaired  

NASA Astrophysics Data System (ADS)

An Image Transceiver based- Goggle has been under development at the Ben Gurion University and the Holon Institute. The device , aimed at Low-Vision Aid applications [1], is based on a unique LCOS-CMOS Image Transceiver Device (ITD), which is capable of combining both functions of imaging and Display in a single chip. The head mounted Goggle will allow the capture of ambient scenery, performing the necessary image enhancement and processing, as well as its redirection to the healthy part of the patient's retina. In this presentation we will report on the modeling of the imaging, Image Perception and discrimination capabilities of the visually impaired. The first part of the study is based on modeling the spatial frequency response and contrast sensitivity analyzing the two main cases of central and peripheral vision losses. Studies of the effects of both the Retinal Eccentricity and illumination-levels on the low vision's spatial frequency response will be described. The second part of the modeling incorporates the use of an image discrimination model to assess the ability of the visually impaired using the low vision model outlined above, to discriminate between two nearly-identical images.

Benguigui, Avi; Efron, Uzi



Artist's colour rendering of HDR scenes in 3D Mondrian colour-constancy experiments  

NASA Astrophysics Data System (ADS)

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.

Parraman, Carinna E.; McCann, John J.; Rizzi, Alessandro



The colour of galaxies in distant groups  

NASA Astrophysics Data System (ADS)

We present new optical and near-infrared imaging for a sample of 98 spectroscopically selected galaxy groups at 0.25 < z < 0.55, most of which have velocity dispersions ? < 500kms-1. We use point spread function matched aperture photometry to measure accurate colours for group members and the surrounding field population. The sample is statistically complete above a stellar mass limit of approximately M = 1 × 1010Msolar. The overall colour distribution is bimodal in both the field and group samples; but, at fixed luminosity the fraction of group galaxies populating the red peak is larger, by ~20 +/- 7 per cent, than that of the field. In particular, group members with early-type morphologies, as identified in Hubble Space Telescope imaging, exhibit a tight red sequence, similar to that seen for more massive clusters. Using optical and near-infrared colours, including data from the Spitzer Space Telescope, we show that approximately 20-30 per cent of galaxies on the red sequence may be dust-reddened galaxies with non-negligible star formation and early-spiral morphologies. This is true of both the field and group samples, and shows little dependence on near-infrared luminosity. Thus, the fraction of bright (0.4MK < -22) group members with no sign of star formation or active galactic nuclei activity, as identified by their colours or [OII] emission, is 54 +/- 6 per cent. Our field sample, which includes galaxies in all environments, contains 35 +/- 3 per cent of such inactive galaxies, consistent with the amount expected if all such galaxies are located in groups and clusters. This reinforces our earlier conclusions that dense environments at z <~ 0.5 are associated with a premature cessation of star formation in some galaxies; in particular, we find no evidence for significantly enhanced star formation in these environments. Simple galaxy formation models predict a quenching of star formation in groups that is too efficient, overpopulating the red sequence. Attempts to fix this by increasing the time-scale of this quenching equally for all group members distort the colour distribution in a way that is inconsistent with observations.

Balogh, Michael L.; McGee, Sean L.; Wilman, Dave; Bower, Richard G.; Hau, George; Morris, Simon L.; Mulchaey, J. S.; Oemler, A., Jr.; Parker, Laura; Gwyn, Stephen



Advanced night vision goggles  

NASA Astrophysics Data System (ADS)

The Advanced Night Vision Goggle (ANVG) program is developing integrated wide field of view (WFOV) helmet-mounted image intensifier night vision goggle systems. ANVG will provide a FOV of approximately 40° (vertical) × 100° (horizontal) and an integrated heads-up display for overlay of flight symbology and/or FLIR imagery. The added FLIR complements the I2 imagery in out of the window or ground applications. ANVG will significantly improve safety, situational awareness, and mission capabilities in differing environments. ANVG achieves the ultra wide FOV using four image intensifier tubes in a head-mounted configuration. Additional features include a miniature flat panel display and a lightweight uncooled FLIR. The integrated design will demonstrate the capability of helmet-mounted I2 and FLIR image fusion. Fusion will be accomplished optically and will offer significant opportunities for ground applications. This paper summarizes the basic technologies, lessons learned, and program status.

Thacker, Clinton



Vision as Adaptive Epistemology  

E-print Network

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 quest...

Licata, Ignazio



Dynamic monocular machine vision  

Microsoft Academic Search

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