Short-term adaptation to vertical yoked prisms.
OBJECTIVE
The purpose of this study was to investigate short-term adaptation to vertical yoked prisms in visually normal subjects as well as to develop normative data for future comparative purposes in patients with acquired brain injury.


METHODS
A full-body enclosure containing a calibrated laser pointer was used to assess egocentric localization (i.e., one's perceived sense of "straight ahead") in total darkness. Fourteen visually normal subjects were tested in a counterbalanced manner under both experimental (20 pd base-down) and control (plano or zero power) test conditions with each test condition lasting 1 hour. A rating scale questionnaire was also administered to assess quantitatively subjective adaptation to the yoked prisms.


RESULTS
Group mean egocentric localization showed approximately 50% adaptation during the 1-hour test period. Subjective adaptation results were similar.


CONCLUSIONS
The findings suggest that rapid perceptually driven, sensorimotor adaptation occurred as assessed both objectively and subjectively in response to vertical yoked prisms. These results are similar to those found in other experiments involving short-term adaptation to optical rearrangements.
Huang
Michael A
MA
SUNY State College of Optometry, Department of Vision Sciences, New York, New York 10010, USA.
Ciuffreda
Kenneth J
KJ
D000221:Adaptation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D001248:Asthenopia / Q000503:physiopathology / Q000628:therapy; D004867:Equipment Design; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D013997:Time Factors