Stability of tonic vergence.
Tonic vergence was monitored at 30 min intervals over a 10 hr period of a single day and at intervals of approximately 14 days over a period of 19 weeks. Measurements were also made during a continuous 112 min period in total darkness. Tonic vergence showed neither significant systematic variation nor large random fluctuations during the course of either a day or weeks, demonstrating stability under naturally occurring viewing conditions. During the period in total darkness, however, tonic vergence exhibited a significant decreasing trend, ie, eye position became less convergent with time. Stability was therefore poorer in the absence of visual stimuli.
Fisher
S K
SK
Department of Vision Sciences, Schnurmacher Institute for Vision Research, SUNY/State College of Optometry, New York 10010.
Ciuffreda
K J
KJ
Tannen
B
B
Super
P
P
D000328:Adult; D002940:Circadian Rhythm; D003290:Convergence, Ocular; D003624:Darkness; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D013997:Time Factors