Irlen Scientific Research

A Summary of Research into the Irlen Method

Dr. Greg Robinson and Don Riley review the research into the use of coloured overlays and precision tinted lenses for those with a range of perceptual difficulties that act as significant barriers to learning and achievement.

Background – Origins of the Irlen Method

Helen Irlen, an educational psychologist, began research in 1980 with university students. As Director of the Adult Learning Disabilities University Programme, she obtained a government grant to investigate the mismatch of potential and performance in adult students studying at California State University. Her work established a link between visual disturbance on the page and reading achievement. As the research proceeded, she began to investigate colour filtration as a possible intervention for perceptual difficulties and its effect on the reading process. She found that by using colour, she could eliminate the perceptual difficulties that were preventing students from accessing print and causing physical discomfort during reading.Irlen has been recognised worldwide as the first person to research, categorise and develop a testing method for a specific type of perceptual difficulty. She is also recognised as the first person to develop the technology of systematically using colour, as coloured plastic sheets and coloured lenses worn as glasses or contact lenses, to eliminate the symptoms. Her system has been developed during the past twenty years and the assessment method has been constantly refined and improved.Since this technology has been in use, research has been able to substantiate a deficit in the brain's ability to process visual information and its association with reading disabilities. Twenty years of educational, medical, and academic research has generated a wealth of support for the success of colour in treating these perceptual difficulties associated with Irlen Syndrome. It is important to separate vision and perception since Irlen Syndrome is unrelated to visual skills as assessed by an optometric exam (Evans, Busby, Wilkins & Jeanes, 1995)

People with Irlen Syndrome perceive and interpret their world differently, whether while reading or observing their environment. It is as if they are wired differently. Because they have no other point of reference, most children and adults with this problem are unaware that they have it. As a result, they don't discuss it with others. In addition, they may take it for granted that they experience physical symptoms when reading. They think it is normal to get tired or have a headache or stomach ache when reading or sitting under bright or fluorescent lights. They suffer in silence, wishing they could perform better and please their parents and teachers.Those with Irlen Syndrome report a vast array of symptoms, all of which need to be dealt with by the appropriate colours. The range and severity of symptoms varies from person to person. They include: blurring and movement of print and objects in the environment; flickering, pulsating, swirling, floating of print; white background competing or overtaking the print; visual discomfort such as fatigue, strain, headaches, dizziness and nausea.Most individuals do not have Irlen Syndrome and therefore are not bothered by fluorescent lights, textbooks printed on glossy white paper, white boards, and overhead projectors. But for individuals with Irlen Syndrome, the classroom is a very stressful environment. Many other environments, such as the workplace, restaurants, shopping malls and supermarkets, are equally stressful for those with Irlen Syndrome.

A Subset of Individuals

There has always been some confusion about Irlen Syndrome. Some people have wrongly classified the syndrome as a form of dyslexia. However, the Irlen Method is another way of looking at a subset of individuals who, in reality may not be dyslexic or have ADD / HD or specific learning disabilities, but who may manifest symptoms similar to those displayed by individuals with those disorders. On the other hand Irlen Syndrome may co-exist with these other difficulties. These individuals may or may not have fundamental difficulties in language processing at the level of the phoneme, but they do have difficulty with a subset of perceptual and processing abilities that prevent the easy and efficient use of reading skills, thus interfering overall with learning and attention. When incidence data has been collected on this type of processing deficit, it consistently appears as one layer of difficulty in large numbers of people identified with reading, attention or learning difficulties, with estimates of incidence in the general population of 12% to 20% (Evans, Patel, Wilkins, Lightstone, Eperjesi, Speedwell et al., 1999; Jeanes, Busby, Martin, Lewis, Stevenson, Pointon et al., 1997; Scott, McWhinnie, Taylor, Stevenson, Irons, Lewis et al., 2002). It may not be the only difficulty or major problem, but reducing or eliminating this layer can be very beneficial to the educational process of the individual, allowing them to benefit more from other programs or therapies, and reducing their overall level of difficulty.

Irlen Syndrome: Neither an Optical nor a Medical Problem

Diagnosis and treatment with Irlen Filters has been reviewed by the USA Medical Board, and has been determined as not the practice of medicine; it has also been reviewed by various USA Boards of Optometry and has been found not to be the practice of optometry. 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, Wingfield, Jeanes, & Bald, 1996; Evans, Wilkins, Busby, & Jeanes, 1996; Scott, McWhinnie, Taylor, Stevenson, Irons, Lewis et al., 2002; Simmers, Gray, & Wilkins, 2001). The problem is not a medical condition. It is not pathological, nor a disease. It is not, as far as is known, a visual problem due to any abnormality of the eye. As a perceptual problem, it is similar to other processing problems (visual and auditory) which are diagnosed by psycho-educational testing and treated within the educational system.In the USA, there are over 4,000 schools that have implemented the Irlen method. Worldwide, over 100,000 people have been provided with Irlen Filters; Arizona has passed a bill designating funding for a pilot project and within two years Irlen screening will be mandatory in all schools in that state; California has funded a pilot project for the diagnosis and treatment of inmates at Mule Creek Prison, and Alabama has recognised Irlen Syndrome/Scotopic Sensitivity as a learning disability. In the United Kingdom, the Medical Research Council has funded extensive research into the Irlen Method and coloured filters at Cambridge University and now at Essex University. There have also been studies into the prison population affected by the syndrome as well as studies reporting the positive effects of coloured overlays and filters on reading comprehension, accuracy and speed.

The Research

Research projects are ongoing around the world. Some of these concern the use of Irlen filters, others are investigating the principle of colour filtering. In a recent survey, it was possible to identify 63 studies involving coloured overlays, coloured computer monitors or coloured lenses. Many of these would be considered to have adequate experimental controls and many were published in peer reviewed journals, conscious of guarding their reputation by not accepting papers with serious methodological flaws. Of the 63 studies reviewed, only 6 produced fully negative results, with 42 finding positive results for particular reading skills, 4 having mixed results and 11 finding improvements in accommodation facility, eye movements while reading, and reduced headaches/migraine. A number of these studies have used placebo controls (Bouldoukian, Wilkins, & Evans, 2002; Jeanes, Busby, Martin, Lewis, Stevenson, Pointon et al., 1997; Robinson & Foreman, 1999; Wilkins, Evans, Brown, Busby, Wingfield, Jeanes, & Bald, 1994; Wilkins & Lewis, 1999).

In addition, a credible scientific theory has been presented and discussed in the literature for some years. This theory relates to a deficit in the magnocellular visual neurological pathway. A recent review of research and series of studies relating to this theory has been published by Chase et al. (2003). The paper by Chase et al. reviews a number of studies which suggest that red light disrupts magnocellular tasks and that the use of blue filters (which filter red light) results in an improvement in reading performance.

In Australia, Associate Professor Greg Robinson from the Special Education Centre at the University of Newcastle, has completed a placebo-controlled study of the use of Irlen Filters, and has published numerous other papers on the subject, including evidence of biochemical anomalies in people with Irlen Syndrome. Fundamental research is being conducted by Dr Jeff Lewine, Associate Professor of Radiology and Director of Functional Brain Imaging, University of Utah, and Professor G. Barbolini, Universita Degli Studi Di Modena, Dipartimento Di Scienze Morfologiche E Medico, Italy. Brain research at the cellular level has provided new information regarding the operation of the visual pathways in dyslexics as opposed to normal readers, and provides a plausible explanation for the demonstrated effectiveness of Irlen filters whether in the form of lenses or acetate sheets. A single-subject study carried out in the US Naval Air Warfare Center Weapons Division purports to demonstrate, among other things, that the Irlen effect is real, and that varying the energy spectrum presented to the eye of this dyslexic individual was capable of altering visual and cognitive performance for better or worse, to a significant extent.

In light of the ongoing research and the results of clinical surveys, it seems important that this technology be widely available to individuals who suffer with learning disabilities, whose disabilities are not easily resolved by other methods, or for whom Irlen Syndrome may constitute one layer of the disability. While the Irlen Method does not assist all people with learning disabilities, it constitutes a relatively cheap, non-invasive and safe intervention that appears materially to assist a significant number of people with learning disabilities.