Application of ChromaGen haploscopic lenses to patients with dyslexia: a double-masked, placebo-controlled trial.

Background: Many patients with dyslexia report distortion to text when they are reading. After a successful pilot trial of an improvement in reading rate using ChromaGen haploscopic filters in comparison with the Intuitive Colorimeter, a full-scale, randomized, cross-over, double-masked, placebo-based trial was undertaken.

Method: The Wilkins rate of reading test was used to produce a baseline score, against which scores with ChromaGen lenses, placebo lenses, and a control were compared. Exclusion criteria included no formal dyslexia diagnosis, contraindications to contact lens wear, and uncorrected visual causes for reading difficulty.

Results: Forty-seven individuals successfully completed the trial, of which 41 reported distortion to the text (e.g., words appeared to move, were blurred, or patterns or spaces seemed to form in the text) when the patients were reading, and nine were color deficient. A comparison trial of ChromaGen lenses with placebo lenses demonstrated a significant improvement in the reading rate with ChromaGen lenses in individuals who reported distortion to text (p = 0.05) and a highly significant improvement in non-color-deficient individuals who reported distortion (p = 0.006). T-tests of the repeated measures showed that ChromaGen lenses produced a highly significant improvement in the rate of reading--over and above the placebo--in non-color-deficient individuals who reported distortion (p < 0.0001).

Conclusion: The significant increase in the reading rate amongst those who reported distortion suggests that by decreasing the distortion to text, a substantial proportion of dyslexic patients--in combination with their normal reading programs--would benefit from this aid.