While the use of this unsupported intervention may not pose an imminent harm, use of coloured lenses and filters might deprive people affected by dyslexia of effective interventions such as targeted phonics instruction, as well as waste valuable time and resources associated with gaining a prescription for coloured lens or sheets. Some people experience visual discomfort or disturbance when they read. Common symptoms that may significantly impair reading ability, or make reading very tiring, include: Irlen: Irlen lenses, also known as Irlen Spectral Filters, are coloured overlays or lenses that aim to reduce perceptual distortions and visual stress experienced by some people with dyslexia. The specific colours are customised for each individual based on their symptoms. Research has demonstrated that people with dyslexia often have difficulty processing and representing the specific sounds of language. As a result, someone with dyslexia will experience difficulties in associating printed letters with relevant speech sounds, thus causing reading difficulties. The majority of research on this topic has found little evidence of measurable effects on reading accuracy or comprehension. For example, the American Academy of Paediatrics found little to no evidence supporting the link to visual stress in explaining the reading difficulties of people with dyslexia.

But disagreement among researchers still exists over the mechanisms and theory behind the filters’ effects. And debate still rages surrounding the fundamental issue of which colour is needed to achieve optimal results. Myth versus evidence Blue light therapy has also been shown to help people with sleeping problems, to improve alertness during night shift work and to help overcome jet lag. This probably also works on the suprachiasmatic nucleus to alter the timing of diurnal rhythms. We found that children whose reading benefitted from wearing blue filters during the day also often reported that their sleeping patterns had improved, and we showed that this was probably due to an effect on the SCN; at night secretion of the sleep hormone, melatonin, which is also under the control of the SCN, can be inhibited by just 15 minutes of blue light ie blue light can reset the SCN rhythms to improve sleeping. Proponents of this theory say that prescribed coloured eyeglasses or plastic overlays could alleviate perceived visual distortions. It is believed that the removal of this visual stress would improve reading and facilitate the development of reading skills in the longer term and help people with dyslexia. The simplicity of the intervention has helped it to become embedded into the practice of teachers, educational psychologists, optometrists and NHS orthoptic departments across the UK.

The vision screening that most children undergo at school entry (age 4 to 5) is only a test of whether a child can see clearly in the distance. It is not a comprehensive assessment of eyes or vision and does not test any of the functions required for clear and comfortable vision when reading. For this reason, every child should have a full sight test when they start school, and as frequently as recommended by their optometrist after that. There are different types of colour filters that can aid reading for people with dyslexia. Find out all about dyslexic glasses and overlays here. How do Tinted Glasses and Lenses Work?

Please note the colours shown in the pictures may not be an exact representation of the colour in real life. Our 10 scientifically selected colours; can be combined to make 30 tints equally around the colour spectrum The effectiveness of dyslexia glasses and lenses can vary from person to person, as dyslexia is a complex condition with individual differences. One side of the overlay has a matt coating. Some matt coatings can reduce transparency, but coloured overlays from Crossbow Education have been subjected to stringent testing to ensure that maximum print clarity is retained while reflected light from the overlay surface has been significantly reduced. Nevertheless, some people prefer using the gloss side of the overlay. To make matters worse English is littered with exceptions to the letter-sound rules. Compare bough, dough, lough, cough, enough! After all that effort on reading each word, many children can't remember the words they read at the beginning of a sentence to understand the whole thing.Coloured filters, either worn as spectacles or used as overlays, have been successfully employed in the treatment of dyslexia for many years but there is no agreement about how they work. As we have seen, bright blue light increases the activation of the parts of the brain involved in directing attention, such as the posterior parietal cortex. Abnormal function in these attention-modulating parts of the brain has been implicated in the pathogenesis of dyslexia. It is therefore likely that blue light, selected optimally to recruit melanopsin RGCs, will have the greatest effect on improving alertness and concentration and may therefore be the best for remediating the impaired attentional responses seen in dyslexia.