Visual stress (sometimes called ‘Meares-Irlen Syndrome’ or ‘Scotopic Sensitivity Syndrome’) is the experience of unpleasant visual symptoms when reading, especially for prolonged periods. Symptoms include illusions of shape, movement and colour in the text, distortions of the print, loss of print clarity, and general visual irritation. Visual stress can also cause sore eyes, headaches, frequent loss of place when reading, and impaired comprehension.
Visual stress is caused by the striped effect of black writing on white paper which causes over stimulation and excitation of the visual cortex.
Visual stress can have an adverse effect on the development of reading skills, especially reading fluency – i.e. the ability to recognise words quickly and to read longer passages of text in a smooth and efficient way so that good comprehension is maintained. Visual stress makes reading an unpleasant and irritating activity that children will tend to avoid as much as possible. Research
has shown that 15 – 20% of people suffer visual stress to some extent, and they also tend to be hypersensitive to fluorescent lighting and flicker on computer monitors.
White paper or backgrounds can appear too dazzling and make print hard to decipher.
Good lighting can help overcome some visual problems and in particular the avoidance of white boards and white paper. Coloured filters can help settle down visual disturbance.
Visual Stress and Specific Learning Differences, particularly as it relates to Dyslexia, is a controversial subject with mixed opinions as to effects, diagnosis and solutions. We are not sufficiently qualified to comment on this but we agree with the opinion of many Special Needs practitioners that “if it helps then use it”. Many practitioners do use coloured overlays, tinted paper and such like and find that with many individuals it helps but for some it doesn’t.
Our only advice would be that if you suspect Visual Stress is causing a problem do try a range of relatively cheap coloured overlays to find the colour that best works or alternatively get an assessment. If you are considering spending large sums of money on coloured reading glasses do ensure that you go to a qualified optometrist to get this done.