Aging and visual function of military pilots: a review.

This report reviews what is known about the effects of age on visual function and discusses the implications of age-related changes in vision for the flying performance of military pilots. Most visual functions decline to some degree with age, and the rate of decline has been roughly characterized in the general population. There is, however, virtually no data on military pilots, and extrapolation from the general population requires caution. Individual variation in the effects of age is great, and military pilots are a select group presumably in better general health than the general population. Several visual functions that decline with age seem particularly relevant to pilot performance: contrast sensitivity, dynamic acuity, recovery from glare, function under low illumination, and information processing. Vision examinations currently given to military and commercial pilots do not measure these visual functions. The feasibility of supplementing existing vision examinations with measurements of these functions should be explored; such an assessment should consider both research issues and policy implications. Research is needed on several major problems in this area. It is not possible at present to characterize well the effect of changes in visual function on the performance of complex tasks, such as flying. This report suggests several specific measures that might help characterize the effects of changes in visual function on pilot performance. Data on changes in visual functions with age should be collected from military pilots, preferably with multivariate, longitudinally designed studies. Research is suggested to assess the extent to which experienced pilots may compensate for declining visual functions and to determine how such compensation is achieved. The report suggests studies on the interaction of age with other factors, such as cardiovascular changes, that may affect performance, especially under stress.