OBJECTIVE To assess whether population screening for impaired vision among older people in the community leads to improvements in vision. DESIGN Systematic review of randomised controlled trials of population screening in the community that included any assessment of vision or visual function with at least 6 months' follow up. SUBJECTS Adults aged 65 or over. MAIN OUTCOME MEASURE Proporti...

OBJECTIVE To assess the effect of dominant and non-dominant vision in controlling posture in quiet stance. METHOD Twenty-five healthy elderly subjects aged over 60 years old and twenty-five young subjects aged under 30 years old were assessed by computerized dynamic posturography. Postural stability was measured in two conditions; dominant eye open and non-dominant eye open. We used the senso...

The reasons for the circular sense of human color perception generated by two sorts of color opponent neurons and three cone types are not well understood. Here we use geometrical analysis to examine the hypothesis that opponency, the recursive nature of color perception, and trichromacy arise as the most efficient ways of distinguishing spectrally different points on a plane using a minimum of...

PURPOSE To develop and assess new color vision tests to be used in evaluating faulty color recognition. METHODS We developed new color vision tests to evaluate faulty color recognition. The two types of color vision tests, designed to assess faulty color recognition in color vision deficiencies, are based on principles that are different from those of the conventional color vision tests. In t...

Recently, Marr & Poggio (1979) presented a theory of human stereo vision. An implementation of that theory is presented, and consists of five steps. (i) The left and right images are each filtered with masks of four sizes that increase with eccentricity; the shape of these masks is given by delta 2G, the Laplacian of a Gaussian function. (ii) Zero crossings in the filtered images are found alon...

While 3D experiences through binocular disparity sensitivity have acquired special status in the understanding of human stereo vision, much remains to be learned about how binocularity is put to use in animals. The owl provides an exceptional model to study stereo vision as it displays one of the highest degrees of binocular specialization throughout the animal kingdom. In a series of six behav...

Techniques that involve the use of comb-filtered spectra to study human colour vision have been developed in previous work (Bonnardel, V., Bellemare, H., Mollon, J.D., 1996. Measurements of human sensitivity to comb-filtered spectra, Vision Research 36, 2713-2720; Bonnardel, V., Ruderman D.L., Barlow, H.B., 1997. A fast determination of the Spectral Modulation Sensitivity Function: a comparison...

OBJECTIVE To compare visual and visual-information processing skills between children with and without mild reading and academic problems and examine the incidence of visual deficits among them. METHOD Seventy-one seventh graders classified as proficient (n = 46) and nonproficient (n = 25) readers were compared with respect to scores on an accepted vision screening, on tests of visual-percept...

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 reve...

Colour vision deficiency (CVD) affects the everyday lives of a large number of people, but it is difficult for others – even friends and family members – to understand the experience of having CVD. Simulation tools can help provide this experience; however, current simulations are based on general models that have several limitations, and therefore cannot accurately reflect the perceptual capab...