A migraine is an intense throbbing or pulsing sensation in one area of the head, and is commonly accompanied by nausea, vomiting, and extreme sensitivity to light and sound. They can last hours and some people find it difficult to function while others try their best to go about their daily lives even with the pain. It gets even more difficult, however, when there is a constant barrage of bright lights that exacerbate the migraine headaches that make people want to reach for the Excedrin or Imitrex a lot quicker and more frequently.
A new study out of Harvard Medical School suggests that when such photophobic patients are exposed to a pure wavelength of green light, it significantly reduces their migraines. It tends to exacerbate the headaches significantly less than all the other colors of light and at low intensities it may even reduce the headache itself. The study asked patients undergoing acute migraines to report any change in headache when they were exposed to various intensities of blue, green, amber and red lights. 80% of patients reported intensified headaches in all colors but green, and in actual fact, green light reduced their pain by about 20%.
To be able to understand why this occurred, the scientists devised a method of experimentation where they measured the amount of electrical signal generated by the retina of the eye as well as the cortex of the brain in response to each color the patients were exposed to. They found that the green light had the smallest electrical signal generated in both retina and cortex. They then proceeded to use animal models to show that the thalamus (the brain area that transmits information about light from the eye to the cortex) actually extrapolates the information coming into the retina as painful when getting blue, red and amber light. The reaction was reduced with green light.
This study can be the beginnings to the development of narrow wavelength green light bulbs that can help reduce migraine headaches as well as develop polarizing sunglasses that can filter out all other colors except this green, allowing migraine patients to be a lot less dependent on drugs.Source: BRAIN: A Journal of Neurology