Influence of ocular gaze and head position on 4 m heterophoria and fixation disparity.

Four-meter heterophoria and fixation disparity measurements were taken from a sample of 40 young adults in primary gaze, 33 degrees left and right lateral gaze, and in 2 head/gaze positions related to golf putting. Comparisons using analysis of variance were made between the mean values in each gaze position and between the test-retest range of values in each gaze position. Mean heterophoria was more eso (p less than 0.05) in the two head/gaze positions related to golf putting than in other gaze positions, whereas mean fixation disparity was more eso (p less than 0.05) in rightward than in primary gaze. Phoria test-retest range was less (p less than 0.05) in all nonprimary gaze positions than in primary gaze. One of the putting-related gaze positions showed smaller (p less than 0.05) fixation disparity ranges than the primary or leftward position of gaze. All measures were highly variable among subjects. Trends present in the data suggested greater esophoria and eso fixation disparity mean values, and lesser heterophoria and fixation disparity test-retest range values in all nonprimary positions relative to primary gaze. The behavior of exophoric and esophoric subjects differed only in regard to changes in heterophoria associated with left and right lateral gaze. These data indicate differences in oculomotor postural tendencies relative to position of gaze. Relevance of the results to athletes is discussed.