Visual Stress

Distressing symptoms that interrupt reading and that may be relieved by looking through coloured glass or plastic are known as ‘visual stress’.

Although visual stress can be caused by defective eyesight there are many cases where defective eyesight is not to blame. This is then known as Meares-Irlen Syndrome (MIS). MIS can be caused by contrasting striped patterns or to the on-off nature of some lighting or light effects.

There have been claims that visual stress occurs in at least 20% children in general and 65% children with dyslexia. There are similar estimates for adults Further and Higher Education. Visual stress can discourage reading and impair comprehension.

Some symptoms are:

page too bright

print moving vibration, shifting side to side or up and down, words breaking up, words joining up, letters muddling, three dimensional movement, movement of words around the word the individual is attending to movement of words at the beginning and end of lines, words falling off the page.
print changing in size or blurring. Doubling of letters, extra letters appearing at the ends of words. Letters fading or becoming darker.

illusions of shape and patterns and motion appearing in the dark print or in the white spaces, sometimes described as ‘worms’, ‘rivers’ or ‘waterfalls’.

illusions of colour – blobs of colour moving across the page, distracting the reader or obscuring words, highlights of colour around the word or letters (sometimes auras of light or rainbows round people or objects.

more general - eyes tired and sore, nausea, dizziness, discomfort or pain from glare, headaches, photophobia, asthenopia (weakness or fatigue of the eyes, usually accompanied by headache and dimming of vision)

there may be a sensitivity to fluorescent lighting and flicker on computer monitors.

Wilkins Intuitive Overlays Test

This test involves the student choosing the most helpful colour from a selection of plastic coloured sheets (overlays).

Further Sources of Information

www.essex.ac.uk/psychology/overlays/ (information about visual stress)
www.s4clp.org (Society for Coloured Lens Prescribers)
www.crossboweducation.com (for reading rulers)
www.visual-stress.com (images of visual stress+ other information/tests)