Determination of ocular dominance and its association with handedness

Clinical relevance of ocular dominance [OD] lies in its role in success of monovision. This study aims to determine easy and reliable methods to test OD and association of OD with handedness.

Prospective study of 300 patients, with best corrected visual acuity of 6/6, interocular difference of < 1Dioptre, and absence of any ocular, oculomotor or binocular abnormalities. Two subjective tests were done to determine OD-Miles [sighting dominance] and Fogging tests. Handedness was determined by history. Ambidextrous patients and those unable to understand or giving equivocal replies, were excluded. Kappa [k] statistics [inter test agreement], and Chi-Square test and Odds ratio [association between handedness and ocular dominance] were applied.

Mean age 35.28 years, spherical equivalent refractive error ranged +2 and-6 D. Both tests had perfect agreement [k=1]. 67.33% patients were Right Ocular Dominant (ROD) whereas 32.67% were Left Ocular Dominant. 65.67% had matched dominance of eye and hand. No significant association between handedness and ocular dominance.

Mile's and Fogging tests are reliable and easy to perform in clinical setting. Since no direct analogy could be established between patterns of eye-hand dominance, assumption of OD cannot be made on the basis of handedness. As 94.33% patients were Right Handed whereas 67.33% were ROD, the results could not be directly extrapolated in patients with dense cataracts where OD cannot be conclusively determined.