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Colour and Reading Difficulties
Some individuals with apparently normal eyesight experience discomfort when viewing a page in print. Some report that the words appear to move, wobble or flicker while others say that the page appears too bright or that the words are too close together. Some may skip words or lines or report eyestrain and headaches after reading.

This condition is referred to as Meares-Irlen syndrome and is the cause of some cases of migraine and is very often the underlying reason why some individuals struggle to read. Such individuals may be diagnosed as 'dyslexic'

Dyslexia is an umbrella term for many sensory problems which affect learning. Visual stress is NOT dyslexia but its symptoms are often confused with dyslexia as they result in poor reading. Only by using the correct diagnostic assessment can the existence of visual stress be specifically identified. Sometimes the problem of visual stress may run concurrently with other specific learning difficulties, but when visual stress is identified and treated then it is easier to deal with any remaining difficulties associated with learning.

There is now considerable evidence that these symptoms are sometimes relieved by changing the background colour to the print. This can be achieved by placing a coloured filter over printed text (coloured overlay) or by wearing spectacles with tinted lenses. Computer users can be helped in the same way by changing the screen colours. The colour required to achieve optimum relief varies between individuals and may change over time.

Computer screening is fast, thorough and sensitive and compares very favourably with manual screening.

As scientific and anecdotal evidence for the beneficial effects of colour has mounted, an increasing number of teachers, psychologists, optometrists, orthoptists, and others have started screening for Meares-Irlen syndrome. The conventional method of screening involves manually presenting a range of coloured overlays/filters and asking the patient to report which colour is optimum in terms of reducing any symptoms. This process is somewhat tedious and prone to a variety of subject and examiner biases.

In a bid to improve the efficiency of the process, a team of scientist at London's City University, led by Professor David Thomson, started developing a computer screening programme in 1998. After careful evaluation, the City Coloured Overlay Screener was launched in 2001. The programme simulated the coloured overlay testing protocol developed by Professor Arnold Wilkins and provided a reliable indication of the optimum Intuitive Overlay for individuals with Meares Irlen syndrome. Colour Screener PRO builds on the success of the City Coloured Overlay Screener and simulates the effects of coloured overlays and tinted spectacles by changing the background colour of the screen. To simulate an overlay, a portion of the screen is coloured while the surrounding colour is white. To simulate a tinted lens, the screen is viewed in a darkened room and the whole screen is coloured.


How Does It Work?
The cause of visual stress is not fully understood but it has been hypothesised that it may be due to hyper excitability of nerve cells in the visual cortex area of the brain. Individuals with migraine are particularly susceptible. It has been shown that some neurons are differentially sensitive to the spectral power of light. If a colour filter is employed, it is deduced that cortical excitation may be reduced by changing the spectral distribution of the stimulating light and hence improve symptoms.

To determine the optimum colour, a sample of text is displayed on the screen while the colour of the background is changed systematically. The observer is asked to report which colour is most comfortable or which minimises their symptoms. The effectiveness of the colour filter is assessed using a test devised by Professor Wilkins.

Costs
Colour Screener PRO
Computer Analysis                                                £45

Under 21's                                                            £30

Institute of Optometry Overlay                           £10

Precision Coloured
Filter Lenses (inc frame)                            from    £150

Under 21's                                                 from    £135

With NHS Voucher                                     from    £99