Special public attention was called to the subject in 1875 by an enquiry into the causes of a railway accident which had taken place in Sweden, from which it appears that colourblindness was the cause of the disaster. Our author having described colour-sensations, goes on to discuss the theories of colour-perception and colour-blindness, classifying the latter defect as total and partial. Total...

suggests, as do our data, that responses to 1-x-OHD, and I-ax, 25-(OH)2D, are different enough to have important implications in treatment. Although hypercalcaemia remains a serious risk with all vitamin D derivatives the rapid reversal that is possible after I-x, 25-(OH),D, treatment makes this agent preferable to calciferol and possibly to 1-x-OHD,. This is particularly so in patients in whom...

Many similarities exist between the perception of depth from binocular stereopsis and that from motion parallax. Moreover, Rogers (1984, cited in, Howard, I. P., & Rogers, B. J. (1995). Binocular vision and stereopsis. Oxford Claridon, New York.) suggests a relationship between an observer's ability to use disparity information and motion parallax information in a depth perception task. To more...

Decreased discrimination of colors caused by adverse environment, such as long-term occupational exposure to or consumption of drugs, substances, and food containing neurotoxic chemicals. Color vision early manifests adverse effects of exposure to an environment that contains neurotoxic substances [1, 2]. The acquired color vision impairments, or dyschromatopsias, can be very subtle (subclinica...

In colour-grapheme synesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it is debated whether visual processing of synesthesia-inducing achromatic graphemes is similar to that of chromatic graphemes. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, ...

The present paper addresses whether topographical jitter or undersampling might limit pattern perception in foveal, peripheral and strabismic amblyopic vision. In the first experiment, we measured contrast thresholds for detecting and identifying the orientation (up, down, left, right) of E-like patterns comprised of Gabor samples. We found that detection and identification thresholds were both...

In goldfish it has been shown that ethambutol shifts the threshold for wavelength discrimination without affecting the absolute sensitivity of the cones. In this study we demonstrate that a similar colour vision disturbance occurs in tuberculosis patients treated with ethambutol. After 2 months of ethambutol treatment, chromatic discrimination was measured with a computerized forced two choice ...

Computational vision systems and applications of pattern recognition have infiltrated into various fields as an important technology. All processing systems by computers are designed as efficient as possible for the intelligent performances. Computational vision often seeks to actualize human vision system for the intelligent performances. Nowadays, these technologies enable to recognize two-di...