On the definition of age-related norms for visual function testing.

Cross-sectional psychophysical and electrophysiologic studies of aging indicate that visual function declines only slightly or not at all until age 50-60, at which time the decline in visual function rapidly accelerates. This accelerated loss of function may reflect an increased rate of natural cellular degradation, or it may reflect an increased proportion of subclinical pathology in the presumed normal older population. This paper provides a critical review of the changes in visual function that occur with age. The results of this review have implications for both the definition of age-matched control groups and for early detection of age-related pathology.