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 .
The Role of Attributional Bias and Visual Stress on the Improvement of Reading Speed Using Colored Filters
This study tested the predictions derived from two explanatory theoretical models of the effects of colored filters on reading speed : the theory of attributional bias and the theory of visual stress associated with reading . The experimental group consisted of 27 secondary school students ( 14 boys , 13 girls ) diagnosed with the Meares-Irlen syndrome ; the control group had 27 students paired in age and sex with the experimental group . The mean age of the sample was 12 years , 10 months ( SD = 8.9 mo . ) . The effects of colored filters on reading speed and accuracy were tested using a  word reading test and a visual stress induction text . The presentation method tapped individuals ' visual sensitivity and response criteria . The results support some predictions of the theory of attributional bias , but more research is needed to assess each theory of reading speed
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 .