Association of near ocular dominance with the monocular and binocular eye movements involved in reading ability

Background: The purpose of this study was to replicate and extend the study by Dr. Diem Thuy Nguyen, who found that less ocular dominant readers preformed better than strong right or left ocular dominant readers in the areas of relative reading efficiency, reading comprehension, and reading rate with comprehension. This study was designed not only to evaluate ocular dominance and reading, but also to compare reading eye movements under monocular and binocular conditions. Methods: Part I of this study included a survey to subjectively determine ocular dominance. The preferred reading eye was defined as the eye that the subject preferred to leave uncovered when alternately covering each eye with a piece of waxed paper while reading printed material at 40 em. This test separated subjects into three groups: right eye dominant, left eye dominant, and mixed (no preference on the waxed paper test). Reading eye movements were recorded by the Visagraph II as each subject read several standardized paragraphs monocularly and binocularly, followed by comprehension questions. Part II involved comparing reading skills for each eye in binocular and monocular reading conditions. Sixty-one 1st and 3 rd year optometry students from Pacific University were tested. Results: ANOV A did not demonstrate any statistically significant relationship between the preferred reading eye and relative reading efficiency, reading comprehension, or reading rate with comprehension. No relationship was found between the preferred reading eye and other reading skill indicators tested, including the number of fixations, regressions, span of recognition, or duration of fixation when reading with the Visagraph II. No improvement or degradation in reading eye movements or reading efficiency were found when reading in monocular or binocular conditions in any of the ocular dominance groups. Conclusions: Ocular dominance does not play an obvious role in the eye movements required for reading efficiency in most readers