While many studies report improvements with coloured lenses , the effect size is generally small and /or similar to the improvement found with a placebo condition .
Consistent with previous review s and advice from several professional bodies , we conclude that the use of coloured lenses or overlays to ameliorate reading difficulties can not be endorsed and that any benefits reported by individuals in clinical setting s are likely to be the result of placebo , practice or Hawthorne effects
PURPOSE There are many anecdotal cl aims and research reports that coloured lenses and overlays improve  reading performance .
Here we present the results of a systematic review of this literature and examine the quality of the evidence .
Colored overlays for visual perceptual deficits in children with reading disability and attention deficit/hyperactivity disorder: are they differentially effective?
The Transient Channel Deficit ( TCD ) model of reading disability was evaluated by examining the effects of color overlays on the reading ability of four groups of children ( n = 15 each ) with reading disability and comorbid conditions involving math and ADHD . These 60 children were evaluated for reading accuracy and rate on measures of word decoding and reading comprehension under three color transparency conditions ( blue , red , no overlay ) . Results indicated that color overlays did not differentially affect the reading performance of individuals with and without reading disabilities . However , blue transparencies significantly improved reading comprehension in all groups , and reduced reading rate . These findings indicate that the TCD model may need to be reexamined . An alternative hypothesis for the observed effects , involving facilitation of attention processes , was posted
While many studies report improvements with coloured lenses , the effect size is generally small and /or similar to the improvement found with a placebo condition .
Consistent with previous review s and advice from several professional bodies , we conclude that the use of coloured lenses or overlays to ameliorate reading difficulties can not be endorsed and that any benefits reported by individuals in clinical setting s are likely to be the result of placebo , practice or Hawthorne effects
PURPOSE There are many anecdotal cl aims and research reports that coloured lenses and overlays improve  reading performance .
Here we present the results of a systematic review of this literature and examine the quality of the evidence .