The effect of volition on the horizontal forced-vergence fixation disparity curve.
An anomalous horizontal forced-vergence fixation disparity curve in the shape of the letters V or U is presented. This phenomenon is associated with an increase in eso fixation disparity with base-out prism. This response is shown to be related to instructional set. Intrusion of voluntary vergence is suggested as the most likely basis for this effect.
Garzia
R P
RP
School of Optometry, University of Missouri-St. Louis.
Nicholson
S B
SB
D000065:Accommodation, Ocular; D003290:Convergence, Ocular; D005133:Eye Movements; D005403:Fixation, Ocular; D006801:Humans; D014836:Volition