Spatial aspects of vertical phoria adaptation

doi:10.1016/0042-6989(93)90060-A

Vision Research

Volume 33, Issue 1, January 1993, Pages 73-84

https://doi.org/10.1016/0042-6989(93)90060-A Get rights and content

Abstract

Vergence adaptation to vertical disparity spreads to unadapted directions of gaze. The spatial spread function for prism adaptation was estimated from aftereffects of a vertical disparity presented at a single position. Constraints limiting the spatial spread of adaptation were investigated with two stimuli of opposite disparity (hyper and hypo), presented at two different eye positions with a separation that varied from 6 to 18 deg in either the horizontal or vertical meridian. On average, phoria adaptation to the single point paradigm spread uniformly across the entire 18 deg test field. A resolution limit for adaptation to the two point paradigm was demonstrated by a reduction of phoria aftereffects with decreasing target separation (crowding). Vertical phoria aftereffects were reduced more by horizontal than by vertical crowding. A disparity gradient limit was demonstrated for a fixed target separation by a reduction of gain (phoria change/stimulus disparity) with increasing stimulus disparity.

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Citation Excerpt :
The main finding of this study was that the adaptive vertical vergence aftereffect, defined as an increase of deviation of 5 prism diopters or more with the prolonged prism adaptation test, was confirmed; and it partly contributes to the difference of distant and near vertical deviation for selected patients with superior oblique palsy. An adaptive vergence system that can correct and reduce binocular alignment errors is required to align the eye positions accurately while fixating upon targets over a wide range of directions along any given meridian18,19 and distance of gaze in normal subjects.20 Hwang and Guyton11 demonstrated that the adaptive vergence aftereffect develops in patients with incomitant vertical strabismus and is related to a decrease of vertical deviation mostly in the primary and downgaze positions.
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Spatial aspects of vertical phoria adaptation

Abstract

Vision Research

Vision Research

Vision Research

Vision Research

American Journal of Ophthalmology

American Journal of Ophthalmology

Vertical prism adaptation in anisometropes

American Journal of Optometry and Physiological Optics

Depth-increment detection function for individual spatial channels

Journal of the Optical Society of America, A

Constraints on learning new mappings between perceptual dimensions

Journal of Experimental Psychology: Human Perception and Performance

Three dimensional visual stimulus deflector

Applied Optics

Accurate three dimensional eye tracker

Applied Optics

Further study of effects induced by anisometropic corrections

American Journal of Optometry and Archives of the American Academy of Optometry

Effects induced by anisometropic corrections

American Journal of Optometry and Achives of the American Academy of Optometry

Rapid nonconjugate adaptation of vertical voluntary pursuit eye movements