Pupil dynamics with periodic flashes: effect of age on mesopic adaptation.

The purpose of this study is to determine the pupillary dynamics with periodical flashes from a peripheral glare source, in similar conditions to night driving, while focusing on dependence with age. We measured two groups of people: youth and adults. Maximum pupil size decreases due to periodic flashes. Latency does not present significant differences. The reduction of pupil size is greater for older adults. The presence of a peripheral and periodic glare source modifies the pupil size. This leads to a reduction of retinal illuminance, which is greater for older adults.