From its discovery 35 years ago, Irlen has been the subject of scrutiny and criticism from a number of groups, particularly optometrists, who have sometimes suggested that the Irlen Method is not supported by scientific research and that the problems associated with Irlen Syndrome can be corrected through standard optometric interventions. Research has shown that binocular and accommodative anomalies may occur in conjunction with the syndrome, but are not considered to be the underlying physiological basis of the condition (Evans, Patel, Wilkins, Lightstone, Eperjesi, Speedwell et al., 1999; Evans, Wilkins, Brown, Busby, Wignfield, Jeanes, & Bald, 1996; Evans, Wilkins, Busby, & Jeanes, 1996; Scott, McWhinnie, Taylor, Stevenson, Irons, Lewis et al., 2002). Irlen has also been reviewed by various USA Boards of Optometry and the USA Medical Board and was found not to be either the practice of optometry or medicine. As a perceptual problem, it is similar to other processing problems (both visual and auditory) that are diagnosed by psycho-educational testing and treated within the educational system.
When it comes to research, often individuals who say Irlen is not supported by research are uninformed, citing second-hand positions based on research that is more than 20 years old. Specifically, early critics of the research have said that it does not control for placebo effects or experimenter bias, and that it lacks validity and reliability. However, there are more than 100 scientific research studies on the topic of Irlen Syndrome that are published in peer-reviewed scientific journals. These studies have most often been conducted by independent researchers with no financial investment in the method. This research has established a hereditary component of the disorder (Loew & Watson, 2012; Robinson, Foreman, & Dear, 2000; Robinson, Foreman, Dear & Sparkes, 2004), a number of biochemical markers for problems associated with Irlen Syndrome (Robinson, Roberts, McGregor, Dunstan, & Butt, 1999; Robinson, McGregor, Roberts, Dunstan & Butt, 2001; Sparkes, Robinson, Dunstan, & Roberts, 2003), and differences between both the anatomy and functioning of brains of individuals with Irlen Syndrome (Chouinard, Zhou, Hrybousky, Kim, & Commine, 2012; Huang, Zong, Wilkins, Jenkins, Bozoki, & Cao, 2011; Lewine, Davis, Provencal, Edgar, & Orrison, 1997; Riddell, Wilkins, & Hainline, 2006; Yellen & Schweller, 2009). The research has repeatedly documented efficacy of both colored overlays and spectral filters, as measured by improvements in a variety of reading skills (Bouldoukian, Wilkins, & Evans, 2002; Nobel, Orton, Irlen & Robinson, 2004; Park, Kim, Cho, Joo, 2012; Robinson & Foreman, 1999; Tyrrell, Holland, Dennis, & Wilkins, 1995; Williams, LeCluyse, & Rock Faucheux, 1992; Wilkins, Evans, Brown, Busby, Wingfield, Jeanes & Bald, 1994), reduction in physical symptoms that include headaches, migraines, eye strain, fatigue, and light sensitivity (Barbolini, Lazzerini, Pini, Steiner, Del Cecchio, Migaldi, & Cavallini, 2009; Bulmer, 1994; Chronicle & Wilkins, 1991; Huang et al., 2011; Wilkins & Wilkinson, 1991), and improved functioning and success in both academia and the workplace (Bulmer, 1994; Irlen & Robinson, 1996; Robinson & Conway, 1994; Robinson & Conway, 2000; Whiting & Robinson, 1988; Whiting, Robinson, & Parrot, 1994).
Over the years, there have also been a few studies that offered negative results, and these limited studies have often been cited as the support for dismissing the validity of Irlen. However, these negative studies have been critiqued in the literature for their methodological flaws (Robinson, 1994; Robinson, Foreman, & Dear, 2000), which include not controlling for uncorrected optometric problems, utilizing inappropriate outcome measures, and, the most egregious error, not screening for Irlen Syndrome to ensure they have selected an appropriate sample for the study. In addition, most of the researchers who published negative findings in the early days of research on the topic have subsequently published positive research and have become some of the strongest proponents of colored filters and colored overlays. These individuals have, in many cases, begun prescribing colored filters and overlays in their own practices.
While admittedly frustrated by the controversy that seeks to prevent a research-based, non-invasive, and easily implementable intervention from reaching individuals who need it most, we find that with controversy comes the drive to continue to advance our technology and document its validity. We continue to push forward in the face of adversity because of the millions of individuals we have helped and for the millions of children and adults who have yet to be helped.
Amen, D.G. (2004). Light and the Brain. Brain in the News Newsletter, AmenClinics.com, June 30.
Barbolini, G., Lazzerini, A., Pini, L.A., Steiner, F., Del Vecchio, G., Migaldi, M., Cavalllini, G.M. (2009). Malfunctioning cones and remedial tinted filters. Ophta, 2(209), 101-105.
Bouldoukian, J., Wilkins, A.J., & Evans, B.J.W. (2002). Randomised controlled trial of the effect of coloured overlays on the rate of reading of people with specific learning difficulties. Ophthalmological and Physiological Optics, 22, 55-60.
Bulmer, J. (1994). Sensory overload and general well being: Can adults be helped by using Irlen lenses? Unpublished honors thesis, Chester College of Higher Education, Chester, UK.
Chouinard, B.D., Zhou, C.l., Hrybousky, S., Kim, E.S., Commine, J. (2012). A functional neuroimaging case study of Meares-Irlen syndrome/visual stress (MISViS). Brain Topography, 25(3):293-307.
Chronicle, E.P., & Wilkins, A.J. (1991). Colour and visual discomfort in migraineurs. The Lancet, 338, 890.
Evans, B.J.W., Patel, R., Wilkins, A.J., Lightstone, A., Eperjesi, F., Speedwell, L., & Duffy, J. (1999). A review of the management of 323 consecutive patients seen in a specific learning disabilities clinic. Ophthalmological and Physiological Optics, 19(6), 454-466.
Evans, B. J. W., Wilkins, A. J., Brown, J., Busby, A., Wingfield, A., Jeanes, R., & Bald, J. (1996). A preliminary investigation into the aetiology of Meares-Irlen syndrome. Ophthalmic and Physiological Optics, 16(4), 286-296.
Evans, B. J. W., Wilkins, A. J., Busby, A., & Jeanes, R. (1996). Optometric characteristics of children with reading difficulties who report a benefit from coloured filters. In C. M. Dickinson, I. J., Murray, & D. Garden (Eds.), John Dalton's colour legacy (pp. 709-715). London : Taylor and Francis
Huang, J., Zong, X., Wilkins, A., Jenkins, B., Bozoki, A., Cao, Y. (2011). fMRI evidence that precision opthalmic tints reduce cortical hyperactivation in migraine. Cephalagia, 31(8):925-36.
Irlen, H., & Robinson, G.L. (1996). The effect of Irlen coloured filters on adult perception of workplace performance: a preliminary survey. Australian Journal of Remedial Education, 1, 7-17.
Lewine, J.D., Davis, J., Provencal, S., Edgar, J., Orrison, W. (1997). A magnetoencephalographic investigation of visual information processing in Irlen’s Scotopic Sensitivity Syndrome. Conducted at The Center for Advanced Medical Technologies, The University of Utah School of Medicine, Salt Lake City, Utah, and Department of Psychology, The University of New Mexico, Albuquerque, New Mexico.
Loew, S.J., & Watson, K. (2012). A prospective genetic marker of the visual perception disorder Meares–Irlen syndrome. Perceptual and Motor Skills, 114(3), 870-882.
Noble, J., Orton, M., Irlen, S., Robinson, G. (2004). A controlled field study of the use of colored overlays on reading achievement. Australian Journal of Learning Disabilities, 9, 14-22.
Park, S.H., Kim, S., Cho, Y.A., Joo, C. (2012). The Effect of Colored Filters in Patients with Meares-Irlen Syndrome. J Korean Ophthalmol Soc., 53(3):452-459. Korean. Published online 2012 March 15. http://dx.doi.org/10.3341/jkos.2012.53.3.452
Riddell, P.M., Wilkins, A., Hainline, L. (2006). The effect of colored lenses on the visual evoked response in children with visual stress. Optom Vis Sci, 83(5), 299-305.
Robinson, G.L. (1994). Coloured lenses and reading: a review of research into reading achievement, reading strategies and causal mechanisms. Australian Journal of Special Education, 18, 3-14.
Robinson, G.L., & Conway, R.N.F. (1994). Irlen filters and reading strategies: effect of coloured filters on reading achievement, specific reading strategies and perception of ability. Perceptual and Motor Skills, 79, 467-483.
Robinson, G.L., & Conway, R.N.F. (2000). Irlen lenses and adults: a small scale study of reading speed, accuracy, comprehension and self-image. Australian Journal of Learning Disabilities, 5, 4-13.
Robinson, G.L., & Foreman, P.J. (1999). The effects of colored filters on eye movement: a long-term placebo controlled and masked study. Behavioral Optometry, 7(4), 5-17.
Robinson, G.L., & Foreman, P.J. (1999). Scotopic sensitivity/Irlen syndrome and the use of colored filters: A long-term placebo controlled study of reading strategies using analysis of miscue. Perceptual & Motor Skills, 88, 35-52.
Robinson, G. L., & Foreman, P. J. (1999). Scotopic sensitivity/Irlen syndrome and the use of colored filters: A long-term placebo controlled and masked study of reading achievement and perception of ability. Perceptual & Motor Skills, 89(1), 83-113.
Robinson, G.L., Foreman, P.J., & Dear, K.G.B. (2000). The familial incidence of symptoms of Scotopic sensitivity/Irlen syndrome: comparison of referred and mass-screened groups. Perceptual and Motor Skills, 91, 707-724.
Robinson, G.L., Foreman, P.J., Dear, K.G.B., and Sparkes, D. (2004). The Family Incidence of a Visual-Perceptual Subtype of Dyslexia. Nova Science Publishers, 27-40.
Robinson, G.L., Roberts, T.K., McGregor, N.R., Dunstan, R.H., & Butt, H. (1999) . Understanding the causal mechanisms of visual processing problems: a possible biochemical basis for Irlen Syndrome? Australian Journal of Learning Disabilities, 4(4), 21-29.
Robinson, G.L., McGregor, N.R., Roberts, T.K., Dunstan, R.H., & Butt, H. (2001). A biochemical analysis of people with chronic fatigue who have Irlen syndrome: speculation concerning immune system dysfunction. Perceptual and Motor Skills, 93, 486-504.
Scott, L., McWhinnie, H., Taylor, L., Stevenson, N., Irons, P., Lewis E., Evans, M., Evans, B., & Wilkins, A. (2002). Colored overlays in schools: orthoptic and optometric findings. Ophthalmological and Physiological Optics, 22, 156-165.
Sparks, D.L., Robinson, G.L., Dunstan, H., & Roberts, T.K. (2003). Plasma cholesterol levels and Irlen Syndrome: preliminary study of 10- to 17-yr., old students. Perceptual and Motor Skills, 97, 745-752.
Tyrrell, R., Holland, K., Dennis, D., & Wilkins, A. (1995). Coloured overlays, visual discomfort, visual search and classroom reading. Research in Reading, 18, 10-23.
Yellen, A. & Schweller, T. (2009). The Yellen-Schweller Effect: Visual Evoked Responses and Irlen Syndrome. http://www.yellenandassociates.com/pdf/Yellen_Schweller_Effect.pdf
Whiting, P., & Robinson, G.L. (1988). Using Irlen coloured lenses for reading: A clinical study. Australian Educational and Developmental Psychologist, 5, 7-10.
Whiting, P., Robinson, G.L., & Parrot, C.F. (1994). Irlen colored filters for reading: a six year follow up. Australian Journal of Remedial Education, 26, 13-19.
Williams, M.C., LeCluyse, K., & Rock Faucheux, A. (1992). Effective interventions for reading disability. Journal of the American Optometric Association, 63, 411-417.
Wilkins, A.J., Evans, B.J.W., Brown, J.A., Busby, A.E., Wingfield, A.E., Jeanes, R.J., & Bald, J. (1994). Double-masked placebo-controlled trial of precision spectral filters in children who use colored overlays. Ophthalmological & Physiological Optics, 14, 365-370.
Wilkins, A., & Wilkinson, P. (1991). A tint to reduce eye strain from fluorescent lighting: Preliminary observations. Ophthalmological and Physiological Optics, 11, 172-175.
Competing interests: I am employed by the Irlen Institute.