Do tinted lenses improve the reading performance of dyslexic children? A cohort study.

The use of tinted lenses as a method to improve reading skills in children with dyslexia has been a controversial issue in recent years. The purpose of the present study was to determine if tinted lenses cause a measurable improvement in the reading performance of dyslexic children. Twenty-four children aged 8 to 12 years participated in the study. Dyslexia was diagnosed in all children by psychological evaluation, and these children underwent an ophthalmic evaluation for inclusion into the study. Participants were graded for speed and accuracy as they read through spectacle frames that contained red-, blue-, yellow-, and green-tinted lenses, a neutral-density lens, and empty frames. All lenses for each subject were of the same density level, with subjects alternately distributed to one of two densities tested (0.12 or 0.30 log units). Each child was asked to select the lens condition that subjectively improved reading ability at the conclusion of testing. One-way analysis of variance of reading performance showed neither improvement nor deterioration attributable to lens color or density when applied to error rates (F = 1.73, P = .14 for a density of 0.12; F = 0.28, P = .92 for a density of 0.30) or to reading rates (F = 0.98, P = .44 for a density of 0.12; F = 0.81, P = .55 for a density of 0.30). In addition, the lens condition that was subjectively preferred by each child did not correlate with actual reading performance (chi 2 = 3.83, not significant; 11.07 needed for significance at P = .05).