Do years or quanta age the retina?

The progressive loss of visual faculties with advancing age is attributed, sometimes, mainly to allegedly inevitable optical deterioration, such as clouding of the media, or again to neurosenescence, as typified by cell-death. The relevant factors are assessed, and it is not thought likely that changes in normal ocular optics account for changes in contrast sensitivity and visual acuity with age. The role of senescent changes in the retina is analyzed. The progressive temporal and spatial patterns of the accumulation of lipofuscin in the retinal pigment epithelium (RPE) and the putative control of its concentration by the crystalline lens are examined following an earlier suggestion that lenticular UVA transmissivity may control the rate of UVA entry into the eye and so perhaps the amount of lipofuscin formed in the RPE. It is suggested that morphological changes attributed to senescence may partly be due to cumyulative effects of irradiation.