There are many research articles about the Irlen Filter Lenses and overcoming reading difficulties. Most of them show steady or dramatic gains in reading ages after the lenses were prescribed. Copies are available if required. A recent major breakthrough in research on dyslexia at Harvard University clearly links disorders in a person’s visual system as a major cause of dyslexia. A team of neuroscientists led by Dr Margaret Livingstone reported their research in the prestigious research journal Proceedings of the American Academy of Science. Their findings show that visual dyslexia is a result of the failure of the visual perception system’s neuro-circuits to keep proper timing, and that colour filters can correct this imbalance.
Even though there has been plenty of research to show that coloured lenses do make a difference, this has been the first major research to show why. Even more recently, Dr Jeff Lewine, neuroscientist and scientific director of the Center for Advanced Medical Technologies, of Utah University, using sophisticated instrumentation such as Magnetic Resonance Imaging and Magnetoencephalography has reinforced these findings. He says, “The data clearly demonstrated that most individuals diagnosed with SSS had a fundamentally abnormal pattern of information processing in which stationary stimuli caused abnormal activitation in brain regions involved in the processing of visual information. Even more intriguing was the observation that individually tailored coloured glasses suppressed the abnormal activity. The data also clearly indicate the ability of coloured glasses to remediate the relevant information processing handicap.” If you are interested in the research articles, please let me know.
Contrary to opinions often espoused, there is a lot of good scientific research into Irlen Syndrome, most of which is very positive. IT IS EVIDENCE BASED. Quite a few of the studies are double masked, randomised, placebo controlled and many are published in the peer reviewed (refereed) sections of reputable journals.
Many show improvements in Reading Ages. Here are a couple of examples. 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. Shows improvements of between 1 year and 2 months and 2 years and 8 months after using overlays for 3 months.
O’Connor, P.D., Sofo, F., Kendall, L., & Olsen, G. (1990). Reading disabilities and the effects of coloured filters. Journal of Learning Disabilities. 23(10): 597-603, 620. Shows improvements of 6.6 months in rate, 6.9 months in accuracy, and 19 months in comprehension after a 2 week period of using the correct overlays.
Other studies concentrate on the brain and what happens when Irlen Syndrome is present.
An American neuro-psychiatrist, Daniel Amen has performed before and after brain scans of people with Irlen Syndrome while reading. He found that when wearing their Irlen Spectral Filters (coloured lenses), their brain was more balanced and more like normal readers.
Click brain scans to view these images.
Visual Evoked Magnetic Fields in Scotopic Sensitivity Syndrome . Jeffery Lewine Ph.D., John Davis, Ph.D., Sherri Provencal, M.A., James Edgar, M.A., and William Orrison, Jr., M.D. This study shows that there is a timing imbalance in visual processing present in those with Scotopic Sensitivity Syndrome (Irlen Syndrome) that is not present in those without the condition.
Dobrin, Robert, M.D., F.A.A.P. Toward an authentic diagnostic impression using clinical composites and Functional Brain Imaging for an improved understanding of Irlen Syndrome . One of the conclusions … was that Irlen Syndrome, … contributed to an altered state of consciousness related to anxiety, with a resulting spectrum of fatigue, irritability, and vulnerability with a diminished cognitive reserve.
Jie Huang, Xiaopeng Zong, Arnold Wilkins, Brian Jenkins, Andrea Bozoki, and Yue Cao. fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine. 2011, Cephalagia. 31(8). 925-936.
More recent studies include the following:
Stephen J. Loew*, Estrella Fernández** and Kenneth Watson* *University of New England (Australia), * *University of Oviedo (Spain)
Incidence of Meares-Irlen/visual stress syndrome in reading and learning disorders: does fluorescentlighting in classrooms affect literacy and numeracy?disorders: does fluorescentlighting in classrooms affect literacy and numeracy? Aula Abierta. 2013. Vol 41(3). 23-32.
This study draws on many sources to link the spread of fluorescent lighting to the decline of literacy and numeracy standards.
Boyle, Christopher and Jindal-Snape, Divya. Visual-perceptual difficulties and the impact on children’s learning: are teachers missing the page? British Journal of Support for Learning. 2012. 27(4), 166-171. These authors ask teachers to take notice of the proven advantages that can occur when Irlen Syndrome is identified and treated.
Other studies identify genetic links and biochemical markers.
Loew, S., Watson, K. A prospective genetic marker of the visual perceptual disorder Meares-Irlen Syndrome. Perceptual and Motor Skills, 2012, 114, 3, 870-882.
G.L. Robinson, D.L. Sparkes, T.K. Roberts, H. Dunstan. Biochemical anomalies in people with irlen syndrome. Eighth International Irlen Conference Brugge, Belgium 7-11 July, 2004.
Some studies make links to other medical conditions.
Loew, S., Watson, K. The prevalence of symptoms of Scotopic Sensitivity/Meares-Irlen Syndrome in subjects diagnosed wirh ADHD: – does misdiagnosis play a significant role? (2013) Hrvatska revija za rehabilitacijska istrazvanja 49, 50-58. Are some Irlen Syndrome people misdiagnosed with ADHD?
Wilkins, A.J., Baker, A., Amin, D., Smith, S., Bradford, J., Ziawalla, Z., Besag, F., Binnie, C.D., Fish, D. Treatment of photosensitive epilepsy using coloured glasses. 1999. Seizure: 8. 444-449. Some epileptics who react badly to lights (flashing, strobe, flickering) can gain relief from Irlen Spectral Filters.
Loew, S., Marsh, N., Watson, K. Symptoms of Meares-Irlen/Visual Stress Syndrome in subjects diagnosed with Chronic Fatigue Syndrome . 2014. International Journal of Clinical and Health Psychology. 14. 87-92. Fatigue is a big factor in people with Irlen Syndrome; in some cases it can lead onto Chronic Fatigue Syndrome.
The generally accepted incidence of Irlen Syndrome is 14-15% in the general population, but 46% of the reading disabled population.(Irlen 2010, pp 76, 77.) However, some studies show over 20% of the general population have the condition. Harbaugh Incidence of Irlen Syndrome in the General Population has compiled a list of ten studies on the incidence of Irlen Syndrome which range from 14 to 36 percent, with an average of 22 percent.