Abstract

A major issue in vision in ageing research is how to distinguish between the effects of changes in the optical and neural systems of the eye on the decline in visual function with age (Sekuler et. al., 1982). Much controversy has arisen with regard to the principal cause of the decline (see Elliott et. al., 1990). The major optical changes occurring with increasing age are reduced retinal illumination and increased light scatter. The first of these is caused by a reduction in pupillary diameter with age (senile miosis) and increased lenticular light absorption. In a previous study we mimicked these changes using the miotic 0.125% Thymoxamine Hydrochloride and a 0.2ND filter, and measured the contrast sensitivity (CS) of a group of young observers both with and without these simulations (Elliott et. al., 1990). We found no significant change in sensitivity and concluded that these optical age changes had no effect on the well-documented decline in CS with age.

© 1991 Optical Society of America