People who experience migraines that are made worse by light might be better off seeing the world in green.
While white, blue, red and amber light all increase migraine pain, low-intensity green light seems to reduce it. The team behind the finding hope that specially developed sunglasses that screen out all wavelengths of light except green could help migraineurs.
Many people experience sensitivity to light during a migraine. Photophobia, as it is known, can leave migraineurs resorting to sunglasses in well-lit rooms, or seeking the comfort of darkness.
The reaction is thought to be due to the brain’s wiring. In a brain region called the thalamus, neurons that transmit sensory information from our retinas cross over with other neurons that signal pain. As a result, during migraine, light can worsen pain and pain can cause visual disturbance, says Rami Burstein at Harvard University.
But not all colours of light have the same effect. Six years ago, Burstein and his colleagues studied migraine in sufferers who are blind, either due to the loss of an eye or retina, or because of retinal damage. They found that people who had some remaining retinal cells had worse migraines when they were in brightly lit environments, and that blue light seemed to have the strongest impact.
The finding caused a flurry of excitement, and the promotion of sunglasses that filter out blue light. But since then, a special class of cells has been discovered in the retina that process only blue light – and seem to be saved from some types of retina damage that can cause blindness. So there was nothing special about blue light in Burstein’s study – it was just that it was the only type of light his volunteers’ eyes could process.
For further info click here at the New Scientist. For purchasing Green Glasses Click here