A Study on the Correlation between Visual Abnormality and Reading Ability Variables

Abstract

Purpose : The purpose of this study was to investigate the correlation between binocular visual function and reading ability. Methods : This study was conducted to examine the binocular function and reading ability of 120 men and women with a mean age of 22.74 and a corrected visual acuity 1.0 or more. The binocular visual function was measured by horizontal heterophoria, near point of convergence, accommodative facility and classified into normal group and abnormal group by clinical criterion. The variables of reading ability were measured by reading rate, number of fixation, number of regression, duration of fixation, comprehension, reading level and using VisagrapⅡ (Readalyzer). The difference in reading ability between the normal and abnormal groups was examined by independent t-test. The correlation of the reading ability variables according to the degree of visual function was analyzed by Pearson's correlation analysis. p〈0.05 was considered significant. Results : In the near and distance, the reading speed of exophoria group decreased and the average number of fixation was increased (p <0.05). In the near exophoria group, the reading rate decreased as the amount of phoria increased, and the reading grade decreased as the average number of regression increased (p <0.05). In the abnormal group compare to normal group, the accommodative facility increased and the reading speed increased by increasing accommodative facility (p <0.05). Conclusions : Regardless of the fixation distance, the exophoria that exceeds the normal range has a greater impact on reading ability than the esophoria. And this is probably because the amount of convergence required for reading is higher than that of esophoia. Exophoria at near and distance and accommodative facility may affect some reading ability such as reading speed, but it may have little effect on reading ability if there is no correlation with other variables. Therefore, in order to improve the reading ability, it is necessary to correct the exophoria and accommodative facility.