Abstract
It is shown that for older age groups there are log-linear deteriorations with age for: (1) daytime or night time accident rates; (2) static visual acuity: (3) dynamic visual acuity: (4) the ratio dynamic/static acuity: and (5) threshold angular movement. The age breakpoints at which these relationships develop appear to be precisely defined but vary with the function concerned between the ages 38 and 55.