Correlation Between the Type of Visual Function and Reading Ability by Tait-Wick and Duke-Elder Method

Abstract

Purpose : The purpose of this study was to investigate the correlation between visual function and reading ability by Tait-Wick and Duke-Elder methods. Methods : In this study, 151 subjects without ocular disease and refractive error were classified by the Tait-Wick and Duke-Elder methods and their reading ability was examined. The visual function test was distance and near heterophoria, near point of convergence, amplitude of accommodation, distance and near fusional vergence, accommodative facility. The reading ability test was performed using ReadAlyzer to measure duration of fixation, numner of regression, reading rate, saccadic in return sweep, and comprehension. Results : Convergence insufficiency significantly decreased by duration of fixation(t=-2.423, p=0.019), significantly increased by numner of regression(t=4.770, p=0.000), and significantly decreased by reading rate than normal group(t=-5.674, p=0.000). In the accommodative facility, the numner of regression view increased and the reading rate decreased with a significant difference compared with the normal group. The other abnormal groups showed no significant correlation with the reading factor. Conclusion : As a result of this study, convergence insufficiency group seems that the reading rate is decreased because the duration of fixation is decreased and the numner of regression is increased because the convergence is not enough when reading. As the facility of accommodation decreased, increased the number of regression and decreased the reading rate. This suggests that even when the test distance is fixed at 40cm, a slight change in the accommodation stimulus occurs during reading and maladjustment has occurred. Some binocular dysfunction may affect the motional elements of reading, but they do not affect cognitive factors.