Dr.PRASHASTI GUPTA
Dr.yogesh gupta, Prof.Amitava Abadan Khan
Abstract
Color contrast sensitivity (CCC) is the minimum resolvable contrast. Contrast threshold (CT) is its inverse.
Adobe Photoshop 7.0 based novel software on an LED backlit display of an Apple Macbook is used to determine CCC for primary colors and looked for differences in age, sex, ametropia and psueudophakia.
6 letters, 49 mm (comparable to 20/60 of Pelli-Robson chart) of similar contrast value and difficulty were presented from a distance of 1m. A desirable response was considered if a subject reads atleast 4 out of 6.Contrast was altered by up/ down keys till reaching desirable end point. CCS is calculated by difference in background/foreground contrast, as percentage (0.39% to 5.88%) for each primary color.
In sample of 100, there is a positive correlation b/w Age and CT of Red(.377), Green(.180), Blue(.248) i.e. negative b/w age and CCS. In pseudophakics CCS is less than phakics(p<0.01). CCS is not affected by sex and ametropia. Results show comparable results with other methods.
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