Interactive Computer Thresholding of Central Acuity under Conditions of Contrast and Luminance Simulating Real World Environments: Evaluation of the Effects of Aging and Optical Correction

Abstract

Purpose: The Central Vision Analyzer (CVA) is an interactive computer device that has been reported to measure functional resolution at fixation under contrast and luminance conditions and fixation times which mimic a number of vision tasks of day and evening activities. The program presents Landolt C’s that are flashed at fixation for 250 msec and tumbled 1 of 4 directions; the program thresholds for the smallest C the position of which is correctly recognized. In sequential fashion, the CVA tests 3 mesopic environments (98% Michelson Contrast, MC, against a background of 1.6 cd/m2, 25% MC against 5 cd/m2, then 50% MC against 1.6 cd/m2) and 3 glare environments (98%, 10% and 8% MC, all against a background of 220 cd/m2). This report evaluates the impact of aging and optical correction method on the resolution acuity measured in normal eyes.