Below are the hyperlinks to various research papers and findings associated with the coloured lens glasses. The first listed show a positive effect of the coloured lens glasses, the later ones do not. A Randomised Controlled study is currently being planned and co-ordinated by Roger Hall, along with input from key academics and experts in the field, to provide a gold standard test of efficiacy.
Doublemasked placebo-controlled trial of precision spectral filters in children who use coloured overlays by Wilkins and colleagues (1994)
- A paper describing the first double-masked placebo-controlled randomised trial of precision tinted lenses for people with visual stress. The researchers conclude that people with visual stress need the colour of lenses to be individually prescribed with precision.
Visual Stress Theory and its application to reading and reading tests by Wilkins (2004)
- The assessment of visual stress symptoms and its treatment using coloured filters were investigated. The increase in spacing and size of text provided to children when reading alongside the use of filters was found to reduce distortions caused by visual stress, however there is not one specific coloured filter that will aid all.
Visual motion sensitivity and reading by Stein (2003)
- Many poor readers have particular problems with the rapid visual processing required for reading due to a mild impairment of the visual magnocellular system. Boosting M-performance using yellow filters or training eye fixation has been found to improve reading performance very significantly. Other factors such as the MHC control region on the short arm of Chromosome 6 have also been linked to reading difficulties.
Yellow spectacles to improve vision in children with binocular amblyopia by Fowler and Colleagues (1991)
- Yellow filters have been suggested to help children with binocular amblyopia as they have been found to remove the blue fringes and blurring caused by chromatic aberrations of the eye which in turn can aid the symptoms expressed by individuals with the condition. The improvement using the yellow lenses was evident even when the children were not wearing the glasses.
Treatment of visual problems in children with reading difficulties: Findings from current research by Stein and Fowler
- The brains of children with severe reading difficulties have shown neurodevelopmental anatomical and physiological anomalies in language and visual areas which may have arisen from impairments of the magno cells in the visual system. After wearing the yellow filters for 3 months, it was found that 25% of these children had improved reading and no longer needed to wear the filters.
Use of visual search in the assessment of pattern-related visual stress (PRVS) and its alleviations by colored filters by Allen, Gilchrist and Hollis. (2008)
- The effects of pattern-related visual stress (PRVS) and its alleviation by coloured filters were measured via various studies. It was found that individualised coloured filter overlays had no effect on reducing PVRS in high-PRVS individuals and therefore should not be regarded as a general purpose solution to PRVS cases
Noble, J., Orton, M., Irlen, S., Robinson, G. (2004).
- A controlled field study of the use of coloured overlays on reading achievement. Australian Journal of Learning Disabilities, 9(2), 14-22. This study investigated the effects of using Irlen coloured overlays on reading rate, accuracy, fluency, and comprehension under regular class conditions. All subjects were screened for symptoms of Irlen syndrome. 71 subjects were identified. After three months of use of overlays, the group demonstrated a significant improvement in reading achievement with mean gains in grade equivalence scores of between 1 year 2 months and 1 year 7 months.
Visual stress in adults with and without dyslexia by Singleton and Trotter (2005)
- Individuals with visual stress that were dyslexic and non-dyslexic were used in the study to identify whether colour would aid both groups of visual stress sufferers or solely be dyslexia-dependent. Intuitive Colorimeter tests were used to assess both the optimal colour and the reading speed of individuals with visual stress. It was found that the optimal colour enabled a larger improvement in reading rate of those individuals that were dyslexic and suffered from visual stress than solely visual stress sufferers that were non-dyslexic.
Coloured overlays and their benefits by Wilkins and colleagues (2002)
- Children in mainstream schools were provided with text on a white background and were then asked to read the same text using 10 different coloured plastic overlays. Approximately 50% of the children saw an increase in reading speed when using one or more of the overlays for 3 months. They were then provided with another random coloured overlay and those who were given the same as used previously, showed the greatest improvement in reading fluency.
L/M Speed-matching Ratio Predicts Reading in Children by Chase et al (Chase and colleagues) (2007)
- In many dyslexics, it has been found that there is an impaired perception of dynamic visual stimuli and reduced activation of the human motion area MT known as a magnocellular (MC) deficit. Results suggest that relative L-cone sensitivity within the MC-pathway may limit orthographic reading performance.
A preliminary qualitative investigation of the effect of prescribed coloured lenses on occupational performance by Konarski & Taylor (2010)
Coloured lenses and reading: A review of research into reading achievement, reading strategies and causal mechanisms. Australasian Journal of Special Education, 18 (1), 3-14. Robinson, GL (1994)
- The paper reviews investigations on the use of coloured filters in relation to possible causal mechanisms, effects on reading achievement and effects on eye movement. Studies of causes suggest a retinal – sensory after-imaging problem, possibly related to the magnocellular visual neurological pathway. Studies of reading achievement suggest this disability may be one causal factor in reading problems but improvement will be influenced by prior word attack skill and willingness to be involved in reading. Investigation of reading strategies suggest that the claimed reductions in print distortions could allow more reading fluency and enable attention to be directed to meaning rather than word identification, which in turn facilitates access to text context as a supplement to word recognition.
Irlen lenses & adults: A small scale study of reading speed, accuracy, comprehension & self-image. Australian Journal of Learning Disabilities, Vol. 5, No. 1, March, 4-13. Conway, RNF & Robinson, GL (2000).
- This study investigated the effects of using Irlen coloured filters on reading speed, accuracy, comprehension and self-image over 6 months of use. Three study groups were used (immediate lens use, delayed lens use and control), involving 33 subjects ranging in age from 18 years to 62 years. The experimental groups demonstrated significant improvements in reading accuracy and comprehension over the 6 months of the study, although there was a plateau effect for the second half of the 6 month study period. The experimental and control groups also improved significantly on scores of self-esteem over the 6 months. It is suggested that the reported reduction in print and background distortions may allow attention to be directed to the processing of continuous text rather than to the identification of individual words, although improvement will be restricted if basic word attack skills are not fully mastered.
The effect of Irlen coloured filters on adult perception of workplace performance. Australian Journal of Learning Disabilities, Vol. 1, No. 3, December, 7-16. Irlen, H & Robinson, GL (1996).
- While limited by small subject numbers (136 subjects), the high incidence of claims of improvements in quality of work, productivity, absenteeism, job satisfaction and initiative when using Irlen lenses support the proposition that significant change may be possible for some employees. The claims of increased reading efficiency and confidence also gain support from a number of other studies.
Other research papers concluding positive results of coloured lens glasses:
Bouldoukian J, Wilkins AJ, Evans BJ. Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties. Ophthalmic Physiol Opt 2002;22:55-60.
Harris D, MacRow-Hill S. A comparative study with the intuitive colorimeter. Optometry Today 1998;38:15.
Harris D, MacRow-Hill SJ. Application of ChromaGen haploscopic lenses to patients with dyslexia: a double-masked, placebo-controlled trial. J Am Optom Assoc 1999;70:629-640.
Mitchell C, Mansfield D, Rautenbach S. Coloured filters and reading accuracy, comprehension and rate: a placebo-controlled study. Percept Mot Skills 2008;106:517-532.
Papers concluding no effect of coloured lens glasses
Do Tinted Lenses Improve the Reading Performance of Dyslexic Children by Menacker and colleagues (1993)
- The case focuses on 24 children aged 8 to 12 who were all diagnosed with dyslexia and underwent ophthalmic evaluation. The children were graded for speed and accuracy using spectacle frames containing various coloured lenses and placebo lenses and were asked to choose the coloured lens that they felt helped their ability to read. It was found that the reading performance showed neither improvement nor deterioration when the coloured lenses were used and the preferred lenses selected by the children had no correlation with their reading performance.
http://archopht.ama-assn.org/cgi/content/abstract/111/2/213 (Abstract only available)
Before reading the paper summary below read this which can be found at
Statistical Problems in “Irlen Colored Overlays Do Not Alleviate Reading Difficulties”
“I am a faculty statistician at the Duke University Medical Center. I read the Ritchie et.al. research in Pediatrics. While there are many important design features that strengthen the study, I do have some serious concerns. First, the study was not adequately powered even if the authors performed the correct analyses. As you know, the problem with underpowered studies is that a “negative” result may simply reflect the inadequate sample size. An underpowered study should not have this type of title “Irlen Colored Overlays Do not Alleviate Reading Difficulties”. Second, the authors have not clearly identified the reason for giving the “wrong” colored lenses. Unfortunately with their data analysis, the addition of the second “treatment” served to further reduce the power. Third, and most embarrassingly, the authors eliminated the best two responses and a third with a strong response. There is absolutely no valid reason to exclude these data points after the fact. The resulting inferences are not correct and need to be fixed. The exclusion of these individuals obviously invalidates the results. I am very concerned that the editors and the peer review process allowed such a grave mistake.” Kevin Anstrom, PhD., Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, USA.
Irlen Colored Overlays Do not Alleviate Reading Difficulties by Ritchie, Sala and McIntosh (2011)
- Children aged 7-12 years old with reading difficulties were assessed by an Irlen diagnostician to test the efficacy of the coloured overlays. The findings of this report were that the Irlen coloured overlays had no immediate effect on children diagnosed with reading difficulty due to the Irlen syndrome.
Christeson GK, Griffin JR, Taylor M. Failure of blue-tinted lenses to change reading scores of dyslexic individuals. Optometry 2001;72(10):627-633
Handler SM, Fierson WM, Ophthalmology tSo, Council on Children with Disabilities AAoO, American Associationfor Pediatric Ophthalmology, Strabismus, American Association of Certified Orthoptists. Learning Disabilities, Dyslexia, and Vision. Pediatrics 201;127:818-856.
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Links to websites showing related research
Helen Irlen has a link to 30 years of research publications at
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