Decreased dynamics in the adaptation phase signifies that short term adaptation exists in convergence and divergence ocular movements

Adaptation is the process in which one optimizes to the present environment. Many physiological systems including the ocular system adapt to its surroundings. The goal of this paper is to study the effects of short-term adaptation on disparity vergence. Disparity vergence refers to convergence, the inward turning of both eyes, and divergence, the outward turning of both eyes. Four subjects participated in this study. A small stimulus of one degree and a large stimulus of four degrees were presented to the subjects using a haploscope. Data were collected using the Skalar infrared limbic tracking system. An experiment consisted of three phases: baseline, adaptation and recovery. Only large stimuli were presented during the baseline and the recovery phase. In the adaptation phase, stimuli were presented in a ratio of 5 small stimuli to 1 large stimulus to determine how the small stimuli affect the dynamics of the larger responses. Dynamics were quantified using the main sequence and results show that adaptation does occur as exhibited by a decrease in the main sequence observed in the adaptation phase compared to baseline. The dynamics in the recovery phase return to values similar to baseline, suggesting that fatigue was not the cause of the decreased dynamics.