[Color categorization and the structure of perceptive color]. / Kategorizatsiia tsveta i struktura pertseptivnogo tsveta.

This paper is an attempt to develop a coherent framework for understanding, simulating, and predicting color categories. The process of color categorization can be understood as a structuring of preceding color experience on the basis of statistical distribution of light in observers environment. A proposed computational model of color categorization includes: 1) distribution of R, G, B pixel values representing a sample of 630 color images of natural scenes (analogue of physical light experience); 2) transformation of the R, G, B pixel values into L*u*v* coordinates of the CIELUV color space (analogue of the process of color perception); 3) distribution of the L*u*v* coordinates representing the sample of the color images (analogue of perceived color experience); 4) k-means clustering algorithm of the L*u*v* coordinates representing the sample of the color images (analogue of the process of color categorization); 5) location and order of color clusters (analogue of location and order of color categories). The proposed computational model enables us to predict the location and order of color categories, being consistent with psycholinguistic data.

[Lipoic acid as a means of metabolic therapy of open-angle glaucoma]. / Lipoeva kislota kak sredstvo metabolicheskoi terapii otkrytougol'noi glaukomy.

A total of 45 patients (90 eyes) with stages I and II open-angle glaucoma (OAG) were examined, 26 of these were administered lipoic acid in a daily dose of 0.075 g for 2 months and 19 were given 0.15 g daily for 1 month. Control group consisted of 31 patients with OAG who were administered only local hypotensive therapy. Vision acuity and visual field were checked up, tonometry, tonography, and campimetry carried out, and levels of nonprotein SH-groups and activity of gamma-glutamyl transpeptidase measured in the lacrimal fluid. Improvement of the biochemical parameters, visual function, and of the coefficient of efficacy of liquid discharge was more expressed in the patients administered lipoic acid in a daily dose of 0.15 g. Color campimetry results indicate improved sensitivity of the visual analyzer under the effect of treatment. Improvement was attained in approximately 45-47.5% of examined eyes, and was more often seen in patients with stage II OAG: in 57-58% eyes. The effect of lipoic acid may be explained by its antioxidant properties and direct influence on ocular tissue metabolism.

[Color campimetry in the diagnosis of diseases of the retina and optic nerve]. / Tsvetovaia kampimetriia v diagnostike zabolevanii setchatki i zritel'nogo nerva.

Color campimetry was realized with the use of an IBM-compatible computer display with a program permitting the registration of brightness sensitivity thresholds and the time of sensorimotor reaction to visual stimuli offered on the display in each point of the visual field. Investigation of light and color sensitivity thresholds and of the time of sensorimotor reaction to stimuli of different spectral composition in normal subjects helped study the functional topography of the retina by the time of sensorimotor reaction and by the brightness sensitivity thresholds. The methods of equalization by the brightness of the stimulus and background by means of recording the time of sensorimotor reaction was tried in experiments with different background brightness and stimulus size and in ophthalmologic examinations of patients with color abnormalities, diseases of the retina and optic nerve, with glaucoma and albinism.

[Possibilities of computer-assisted processing of the results of an examination of the visual system]. / Vozmozhnosti komp'iuternoi obrabotki rezul'tatov issledovaniia zritel'noi sistemy.

The authors present the first results of examining the vision system with the use of an automated programmed complex realized in the 'C' program language in the IBM and Dos operation system, that helped present in a chart the distribution of the ocular light sensitivity and time of the sensomotor reaction in every site of the visual field of 40-50 degrees. The results evidence that computer-aided methods may be effectively used to assess the light sensitivity of the eye, contrast sensitivity, space summation, rod and cone interactions, the topography of color photoreceptors, and the function of the posterior section of the eye in abnormalities of the retina and the optic nerve, as well as to monitor visual function rehabilitation after treatment.