Light, vision, and aging.

Recent research on aging of chromatic and spatial vision processes is reviewed. Changes in these visual processes with advancing age are largely continuous. Age-related declines in visual performance may be explained in terms of reductions in the illuminance of the visual stimulus due to changes in the ocular media and losses of efficiency at a neural level. Thus, some prominent characteristics of the senescent visual system are similar to those of the younger visual system operating at a lower ambient light level. One important determinant of retinal aging may be the light history of the individual, i.e., cumulative exposure to high-energy photons from solar radiation may accelerate retinal aging. If these abstractions from the literature are valid, then it will become more important to control the light environment throughout the life span.