Microdensitometric study of some retinal disorders

Densitometric study of the fundus of 8 patients with different retinal disorders was done, using the microdensitometer MD 100 as a zeiss fundus camera. Curves were obtained and the results denoted that every disorder gives a different curve

Optical density of visual pigments for normal and abnormal persons

A defined part of the dark adapted fundus is bleached by a short flash of light. The fundus of four normal and four abnormal persons [bilateral macular degeneration] were photographed. The values of optical density at several points across several lines passing through the central fovea were obtained. Large difference for normal and abnormal persons appeared

Measurement of the absorption spectrum curve of visual pigments in the living human eye of normal and abnormal persons

The spectral absorption of the visual pigment was estimated for six persons [three normal and three abnormal] by a photographic method. Using Zeiss microdensitometer the value of the optical density was obtained and the value of transmittance were obtained by using DU Spectrophotometer

Wavelength relation with the appearance time of the first and second rivalry colours

An optical system is used in present work to investigate rivalry process of colors in human eye. Three normal observers and one has color defect were employed in this study. It was found that the appearance time of the first and second rivalry depends on the wavelength of the varied color in case of normal observers only

effect of the frame size on the corrective power of the spectacle lens

The correct position of the spectacle lens is to be in the first principle focus of the eye, i.e. 13 mm from the cornea. The size of the frame may result in an increase or decrease of this distance. The variation of the corrective power of the spectacle lens is studied in respect to the distance of the lens from the eye

role of the design of colour blindness test chart on the degree of colour blindness

On testing some patients suffering from colour blindness using the traditional test chart for colour blindess test [Ishihara Chart], It was found that all of them have complete colour blindness and on performing the test on the same persons using another chart [the City University colour vision test] it was found that some of them could do the test successfully, some of them did it partially, and the rest failed in doing the test. This indicates that the test for colour blindness depends on the design of the test chart