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.

Dyslexia assessor Georgina Smith says that coloured overlays can help people with visual stress as well as dyslexia. When Smith assessed some students, who were experimenting with coloured overlay rulers, the students said that they wanted to try their favourite colours at first. Smith thought that it was best for the student to try every coloured overlay ruler available to them for 10 – 15 minutes before deciding which colour worked best for them. Our top 3 dyslexia glasses & coloured overlays recommendations The effectiveness of dyslexia glasses and lenses can vary from person to person, as dyslexia is a complex condition with individual differences. 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? In cerebellar patients he had shown that their unstable vision was due to damage to large nerve cells in the brain, known as visual magnocells, that are specialised for detecting movement. When these magnocells are not working properly the servo system that keeps your eyes fixed on a letter fails, and so the letters appear to move around. So with Sue he set up a clinic to investigate whether children's visual reading problems were due to the same cause.

So why the visual distortions?

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. Symptoms such as these have a variety of different causes, some of which may be due to disease or abnormality, so they must be investigated by a professional who is qualified to diagnose them correctly and give appropriate treatment. Anyone who experiences such difficulties associated with reading should consult a registered optometrist for a full assessment of eye health and visual function. Our 10 scientifically selected colours; can be combined to make 30 tints equally around the colour spectrum Some people experience visual discomfort or disturbance when they read. Common symptoms that may significantly impair reading ability, or make reading very tiring, include: Bright blue light can also improve auditory attention, suggesting that the effects of light on alertness and attention are automatic and not mediated by conscious visual perception. Rather they are mediated by this retino-hypothalamic synchronising system.

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.Likewise we found that in these dyslexics, who often complain of migraine type headaches, the blue filters often improved their headaches. Migraine was previously thought to be due to swelling of the arteries in the membranes surrounding the brain, the meninges. But we now believe that the hypothalamus and specifically the SCN is responsible. Blue coloured filters, worn as spectacles, have been found to be highly effective in reducing the frequency of migraine symptoms. So our blue filters are also often efficacious in reducing migraine. Overlays are similar to the aforementioned tinted glasses. They come in a variety of colours to suit the personal preferences of each individual. 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

That being said, here are a few popular brands and technologies that are commonly associated with dyslexia glasses and lenses: 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. Essilor: Essilor is a well-known eyewear company that offers a range of lenses, including those designed for dyslexia. They have developed specific lens technologies, such as Eyezen lenses, which are designed to reduce visual fatigue and improve comfort during prolonged reading or computer use. Contrary to the coloured lenses research that was conducted in 1999, coloured overlays can be looked upon as controversial. This is because, in an experiment conducted where some participants were asked to read text without an overlay and then with an overlay, there was no significant difference between the reading speeds for either method. For example, Emily, aged 7 when the experiment took place, had a reading speed of 49 correct words per minute (CWPM) without an overlay and 48 CWPM with the overlay. The overlays being referred to as dyslexia overlays can also be considered controversial because they do not only help people with dyslexia, but they can also be beneficial for people with dyspraxia and AD(H)D. What Colour Overlay is Best for Dyslexia?ChromaGen: ChromaGen lenses are designed to help with visual processing issues related to dyslexia. They use coloured filters to modify the wavelength of light entering the eye, which may help improve reading ability for some individuals. Coloured Filters Olive Meares in Australia was the first to suggest that children with visual reading difficulties may see print more easily through certain coloured filters. This was taken up commercially in the USA and UK. But these systems require that each child is individually prescribed a special colour; so the glasses tend to cost a lot! However since the visual magnocellular system is mainly influenced by just yellow or blue light, John & Sue argue that these are the only two colours that will really make much difference. 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.