Temporal characteristics of proximally-induced accommodation.
This study sought to determine whether proximally-induced accommodation (PIA) is capable of sustaining an accommodative response over time. Accordingly, the steady-state PIA response was measured during the course of a continuous 5 min stimulus period for targets located at distances of 0.2 or 6 m. The vergence and accommodation loops were opened by subjects (n = 8) monocularly viewing the targets through a 0.5 mm pinhole, while accommodation was assessed using an objective, open-field, infrared optometer. The mean PIA response did not change significantly during the fixation period. This finding suggests that PIA is indeed capable of maintaining a sustained response. This observation is consistent with the constancy of apparent target distance perception during extended fixation of a stationary object of regard under these conditions.
Rosenfield
M
M
Department of Vision Sciences, State University of New York/State College of Optometry, NY 10010.
D'Amico
J L
JL
Nowbotsing
S
S
Kapoor
N
N
Ciuffreda
K J
KJ
D000065:Accommodation, Ocular / Q000502:physiology*; D000221:Adaptation, Ocular / Q000502:physiology; D000328:Adult; D003290:Convergence, Ocular / Q000502:physiology; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D008297:Male; D013997:Time Factors