The effectiveness of Irlen filters for improving reading performance: a pilot study.

The objectives of this pilot study were to investigate the effectiveness of Irlen filters for improving comfort and reading performance and to determine whether traditional optometric intervention would be effective in relieving the symptoms commonly reported by people seeking help through the use of Irlen filters. Thirty subjects were included in the study: 12 males and 18 females. The ages of the subjects ranged from 9 to 51 (mean = 23.6). They were randomly placed in either an Irlen filter treatment group (n = 11), a vision therapy treatment group (n = 11), or a control group (n = 8). Pre- and posttesting on all subjects included a vision evaluation, reading and intelligence testing, the Irlen scotopic sensitivity screening test, and a symptom questionnaire. Results revealed that subjects in both treatment groups were more comfortable after treatment, although only the vision therapy group showed improvement in vision functioning. The subjects in the Irlen filter group did not show any significant gains in reading rate, word recognition in context, or comprehension.