Review: Laterality preference in sensory and motor functions of symmetrically disposed organisms have been studied for centuries. The relation between handedness and the eyes and vision (ocular sighting dominance) has been a focal point despite their physiologic dissimilarity.
Study: To examine a college varsity baseball team for handedness and ocular sighting dominance to determine if their patterns of eye-hand dominance differed from the normal population and/or contributed to their individual relative success compared to their peers. Specifically: whether crossed eye- hand dominance favors the batter and uncrossed eye-hand dominance favors the pitcher.
Subjects and methods: Twenty five UF varsity players were examined. All were male. Their visual acuity, stereoscopic vision, ocular motility and ocular sighting dominance were determined, the last by a pointing test which allowed the diagnosis of a central form of ocular dominance, but was not per se affected by handedness. Handedness was determined by preferred arm for throwing or hitting. No subject was ambidextrous. A control population was established consisting of the first 100 consecutive adults seen by the first author in the UF Eye Center with 20/20 vision O.U. and a normal eye exam.
Results: The control group displayed eye-hand dominance patterns similar to those previously reported in the literature for the general population. In the experimental group of baseball players, the incidence of conventionally predominant (in normals) ipsilateral or uncrossed eye-hand dominance was much lower (39%) than the normal control population (65%). The incidence of contralateral or crossed eye- hand dominance was 35%, twice that of the normal control population (18%) (p<0.01). The incidence of central ocular dominance with right or left handedness was 26% or 50% higher than a normal control population (17%) (p<0.25). With regard to individual performance, those players with central ocular dominance, whether right or left handed, were the most successful players in both pitching and batting. Pitchers who were uncrossed eye-hand dominant were distinctly more successful than crossed. Batters who were crossed eye-hand dominant were slightly more successful than uncrossed.
Conclusions: The pattern of eye-hand dominance appears related to athletic proficiency for baseball. Warning: Note well: This information may be useful in career guidance but does not justify or medically indicate attempts to alter ocular sighting dominance or eye-hand dominance patterns as these are determined probably genetically or at such an early age that they cannot be successfully altered later. Attempts to so alter them are historically fraught with irremediable psychological or physical injury to the subject, including permanent incapacitating double vision.