TEMPORAL CHARACTERISTICS OF PROXIMALLY-INDUCED ACCOMMODATION

This study sought to determine whether proximally-induced accommodatio n (PIA) is capable of sustaining an accommodative response over time. Accordingly, the steady-state PIA response was measured during the cou rse of a continuous 5 min stimulus period for targets located at dista nces of 0.2 or 6 m. The vergence and accommodation loops were opened b y subjects (n = 8) monocularly viewing the targets through a 0.5 mm pi nhole, while accommodation was assessed using an objective, open-field , infrared optometer. The mean PIA response did not change significant ly during the fixation period. This finding suggests that PIA is indee d capable of maintaining a sustained response. This observation is con sistent with the constancy of apparent target distance perception duri ng extended fixation of a stationary object of regard under these cond itions.