Analysis of eye movements during monocular and binocular fixation.

A University of California author or department has made this article openly available. Thanks to the Academic Senate's Open Access Policy, a great many UC-authored scholarly publications will now be freely available on this site. Let us know how this access is important for you. We want to hear your story! Title: Analysis of eye movements during monocular and binocular fixation. Recordings of the horizontal component of movements of the eyes were made during monocular and binocular fixation. The variation in the vergence of the eyes over time was found to be of the same order of magnitude as the variation in position of the individual eyes, even though the lateral positions of the two eyes are somewhat correlated. The drift and tremor of the two eyes are not correlated; the overall correlation is due to the saccadic movements. Saccades in one eye seem to be always accompanied by simultaneous saccades in the other eye which are almost always in the same direction and about the same in size. The maintenance of binocular fixation does not seem to be dependent on a direct response to or sensing of vergence error. Rather, it appears to be dependent on the saccadic responses of the two eyes to their own fixation errors. INTRODUCTION THE development of high-resolution techniques of T recording eye movements has led to considerable research on the nature of the eye movements which occur while a subject is fixating. Measurements of such movements have been studied in relation to visual acuity and other visual functions and to the mechanisms controlling the occurrence of eye movements. Most of this work has been done under conditions of monocular fixation. Measurements of the motions of the eyes during binocular fixation by Riggs and Ratliff showed that, while there was a considerable tendency for the eyes to maintain convergence during fixation, variations in vergence did occur.' Extensive quantitative measurements of changes in convergence were not made at that time. The present experiments had a dual purpose: to obtain a quantitative description of F p FIG. 1. Schematic diagram of the apparatus. the relative positions of the two eyes during continuous binocular fixation, and to get information relevant to the mechanisms responsible for the maintenance of binocular fixation. Measurements were made under conditions of monocular as well as binocular fixation in order to relate the results under binocular fixation to previous quantitative work. METHOD The …