The Irlen Method was developed in the early 1980s by Professor Helen Irlen, a Californian psychologist. She was the director of a research project, investigating adult reading disabilities at the University of California.
Helen was talking with a group of adults who had severe reading difficulties. Their comments prompted her to ask them what the page looked like to them when they were reading, and she was astonished by some of the comments they made. They described how the letters on the page seemed to move around, how the white page strained their eyes, how they saw streaks of white on the page, how the print went blurry, how they saw ghosting of letters etc. Around her she was hearing people saying, "That's what I see too! When I tell my family they laugh at me."
Helen Irlen called this disorder - Scotopic Sensitivity, a condition where an individual's visual system is sensitive to certain frequencies within the white light spectrum. This appears to be an inherited difficulty which causes rapid fatigue of the visual system resulting in a range of symptoms, most of which interfere with effective and efficient reading performance.
When Irlen Lenses were first used, there was very little scientific evidence to support the theory. However, over thirty years later there are now over a hundred research publications on Irlen Spectral Filter Lenses (also called Irlen Lenses), including research from Harvard Medical School and the Canadian Medical Association.
A recent breakthrough in research on dyslexia at Harvard University clearly links disorders in a person’s visual perception as a contributing factor for those with dyslexia. A team of neuroscientists, lead by Dr Margaret Livingstone, reported research in the prestigious research journal, Proceedings of the American Academy of Sciences. Their findings show that visual dyslexia is the result of the failure of the visual perceptual system’s neuro-circuits to keep proper timing. They reported that coloured filters can correct this imbalance and therefore reduce the effects of dyslexia, including chronic loss of place, reversing words, blurred vision, movement of the print and rapid fatigue when reading.
Dr Drake Duane, an authority on dyslexia and learning disorders at the Arizona State University, states that this research provides "convincing evidence that the nervous system of those who are dyslexic are atypical and provides theoretical support for the one treatment of dyslexia through the use of coloured filters for reading."
Dr Galaburda, Director of the Dyslexia Neuro-anatomical Centre at Beth Israel Hospital in Boston, views this research breakthrough as indication that the visual system consists of two major neural pathways. "One of these pathways, the magnocellular system, is composed of large cells that carry out fast processes and is used for seeing motion, stereoscopic vision, depth perception, low contrast and locating objects in space. The second pathway, the parvocellular system, is composed of smaller cells that carry out slower processes. This system specialises in colour, detailed forms, high contrast and stationary images." Dr Galaburda explains that a neurological timing imbalance or ‘sluggishness’ in the timing between these two systems lead to visual dyslexia.
The visual perceptual demands of the reading process, usually in situations of high contrast with black print on white paper, exacerbate the problem. It also accounts for why a significant number of people with reading difficulties have poor depth perception and are clumsy. In essence, the disturbed synchronisation of the two visual pathways leads to these perceptual disorders. Autopsies conducted by Dr Galaburda on brains of ten deceased people, five known dyslexics and five normal readers, showed distinct anatomical cell differences (in size) when the parvocellular and magnocellular cells were compared.
Professor Mary Williams, University of New Orleans, has completed research which indicates that the ‘sluggish’ timing or lack of synchronisation of these two visual pathways in dyslexic children is corrected with the use of coloured filters.
Dr Solomon, a research psychologist, and Professor Drain, a research optometrist, both at the University of New South Wales - Sydney, recently published research that also provides strong evidence that contrast sensitivity of white to black when reading print on white paper, was a significant factor in creating reading perceptual disorders. Also, coloured filters that were specifically prescribed for particular reading disabled children, dramatically reduced this sensitivity and improved reading.
From this recent research evidence, along with an extensive list of other supporting evidence, Helen Irlen was correct. Carefully and precisely prescribed spectrally modified, Irlen Spectral Filter lenses substantially reduce perceptual disorders for children and adults with what she has classified as Scotopic Sensitivity Syndrome / Irlen Syndrome.
