Abstract

Systematic differences of foveal sensitivity exist among people aged sixty and older who have good acuity and good ocular health in each eye. For example, absolute threshold to 660-nm tests increases with age. The rate of increase is ~0.1 log units per decade. Not surprisingly, blue cone threshold also Increases with age. However, the rate of increase of blue cone threshold appears to be greater for women than for men. Some visual functions do not change with age, at least when change is defined cross sectionally. For example, the rate of threshold recovery following a bleach does not change with age. Nevertheless, the rate of threshold recovery following a bleach can be a sensitive indicator of retinal health, even among eyes which have 20/20 acuity. Specifically, eyes with 20/20 acuity having many macular drusen have slow rates of recovery, at least for that population of eyes whose fellow eye has exudative aging macular degeneration (AMD). Eyes with good acuity but whose fellow eye has exudative AMD tend to have high absolute thresholds at 660 nm and high blue cone thresholds. The elevation of blue cone threshold is greater for 1° than for 3° stimuli. A disproportionate number of these eyes do not have measurable color match area effects, implying that they have low effective foveal cone photopigment densities. Surprisingly, however, red/green color discrimination is no worse for these 20/20 eyes whose fellow eye has exudative AMD than for normal 20/20 eyes.

© 1986 Optical Society of America