What is Visual Stress
What is Visual Stress?
Visual stress describes the discomfort some people feel when viewing text on a page of print or on a screen: sometimes after ten or fifteen minutes; sometimes immediately. Symptoms vary, but can include headaches and migraines (especially when working at the computer), sore eyes and eyestrain, and words or letters blurring or appearing to "jump" or move on the page. Visual stress can also cause fatigue and nausea when reading, and is a common, and often undiagnosed cause of educational failure and under-achievement.
Many people suffer unknowingly from visual stress (see Reading through Colour below), so it is worth checking out anyone experiencing reading difficulties or discomfort, especially after prolonged exposure to print or VDU. Sometimes a simple five minute experiment with different coloured overlays is all that is necessary, as the symptoms can often be alleviated by just changing the background colour of the text - although a thorough examination by an optometrist is also important, to check that there are no underlying eye problems. VISS, a computerized Visual Stress screening programme developed in association with the psychology department of Hull University, is a useful tool for identifying Visual Stress sufferers.
Visual stress is also termed Meares-Irlen Syndrome, Scotopic Sensitivity, or (in the USA) Irlen syndrome.
Reading through Colour
Research has shown that around 20% of the population suffer to varying degrees from visual stress, and could improve their reading by reading through a coloured overlay. When a person has the right tint, a number of aspects of reading can improve, including attention span, reading speed, fluency and comprehension.
Scientists have not yet agreed on the reasons behind the beneficial effects of reading through colour; only that they do exist, and that it is important to find the correct colour for each individual.
What about writing?
Writing on white paper can also cause problems. In the educational sphere, we have found that children scoring 4 or 5 out of 20 on a spelling test have improved their spelling score by 10 marks when switching to paper matching the colour of the tinted overlay they are using for reading. We supply A4 refill pads “Tinted for Visual Comfort” in 7 pastel colours.
Visual Stress and Dyslexia, and are overlays a cure?
Although many dyslexic people experience visual stress, they are not the same thing: not all dyslexics suffer from visual stress, and not everyone experiencing visual stress is dyslexic. There is however a high correlation between dyslexia and Visual Stress: it seems that about three times as many Visual Stress sufferers are dyslexic than not. Coloured overlays are NOT a "cure" for Dyslexia. In the years following the discovery (in 1980) of the benefits of reading through colour there were some commercial interests that took the “Dyslexia Cure” line, and there is still one website that promotes the use of overlays as a “cure”. These claims have resulted in adverse publicity and consequent suspicion of a “quack remedy” that is unfortunately still shared by many people today. Crossbow do not subscribe to that view. Spectacles do not cure short-sightedness: they simply adjust its effects. It is the same with coloured overlays and VDU screen tinting software.
Will my local Optician know all about visual stress?
Maybe; maybe not. However an increasing number are prescribing coloured overlays and lenses.