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Blue-tinted specs that can banish the misery of migraines
Baku, January 11 (AZERTAC). One in seven people in the UK suffers from migraine with common triggers including dehydration, stress and lack of sleep. Steve is one of many thousands of Britons whose migraine is triggered by bright light. While light sensitivity, or photophobia, is a well-known symptom of migraine, many people don`t realize that it can cause it, too — in fact, research has found that 40 per cent of migraine sufferers believe visual triggers are partly to blame. The precise visual trigger varies with the individual, explains Professor Bruce Evans, director of research at the Institute of Optometry in London. For instance, some people develop migraines from seeing black words on a white background, or a pattern such as stripes on a shirt or the lines on an escalator.
Alternatively, they can be caused by a repetitive action, such as light flickering through trees, or even a computer screen.
Colored lenses effectively damp down the effects of lights or patterns that trigger visual migraine, explains Arnold Wilkins, professor of visual perception at Essex University. `One theory is that using color redistributes the excitement in the brain that occurs in a response to something such as stripes,` he says. With dyslexia, for instance, color filters have been shown to improve reading performance in many cases, says Professor Evans.
In a study by the University of Michigan (published in the journal Cephalalgia) brain scans showed hyperactivity in the visual part of the brain when migraine sufferers saw patterns such as stripes or highly-contrasted colors. The hyperactivity was measured by assessing the amount of oxygen in the blood in this part of the brain. The study found `stressful` patterns increased brain activity in both the migraine and a control group, although the increase was greater in the migraine group. But when the migraine sufferers wore tinted glasses, the brain activity was stabilized. About 70 per cent of participants reported significant relief when using the lenses. It seems brain cells in the area controlling vision respond better to different colors, depending on the individual — which means it`s a case of finding the right color that works best for the patient.