Ocular dominance stability and reading skill: A controversial relationship

Purpose. Evidence is mixed concerning the relationship between stability of ocular dominance and reading deficits. Contrasting results may be due to the use of different tests of dominance, different samples of readers, and different scoring methods. The aim of this study was to investigate the relationship among ocular dominance, general visual abilities, and reading performance, and to evaluate the consistency and reliability of different tests of ocular dominance and the effects of different types of eye dominance scoring. Methods. In a group of young adults, we measured: (a) main optometric parameters; (b) reading time and accuracy; and (c) ocular dominance in two sighting and four motor tests. Dominance was determined using different scoring methods (relative, absolute, and binary scores). Results. All dominance tests showed good levels of internal reliability. Sighting tests were consistent regardless of the scoring method, and all participants had stable dominance. Three of four motor tests were moderately consistent when dominance was measured with relative scores but not when it was measured with absolute or binary scores. No relationship was found between stability of dominance and reading performance, regardless of the type of test or scoring method. No systematic pattern of correlation was found between binocular vision variables and dominance measures. Purpose. Choosing the type of motor test to measure ocular dominance is crucial, because the level of consistency among tests is low to moderate. Furthermore, motor tests were not correlated with reading performances. Present results suggest caution when trying to link reading difficulties with specific profiles of ocular dominance.