Most migraine attacks and post-traumatic headache sufferers mostly find their headache get worse as they expose themselves to light, forcing them to quite their daily tasks and seek some comfort in darkness. A new study carried out by Harvard Medical School in 2015 reveals that exposing people with migraine headaches to pure-wavelength green light can significantly reduce their sensitivity to light (photophobia), and can even reduce severity of their headaches. The results were published in magazine called Brain.
Photophobia, mostly associated with 85 percent of migraine attacks, give migraine sufferers very little choice but to force themselves to dark rooms, unable to care for their family, unable to work, or pursue day-to-day activities.
Even though photophobia is not as incapacitating as migraine pain itself, “it’s their inability to work properly in light that most often disables them,” says Sami Burstein, Professor of Anesthesia at Harvard Medical School and Beth Israel Deaconess Medical Center (BIDMC), and lead author of the study.
In this new study, it has been proved that narrow band of green light exacerbates migraine much less than all other colors of light and at low intensities it can also help in reducing headaches.
Burstein and his team devised a novel way to study the effects of different light colors on headache in patients without any visual impairment, after discovering that just blue light hurts the most to blind migraine patients.
The team asked all those who’ve undergone acute migraine attacks in the recent past to report any change in their headache patterns when exposed to different intensities of green, blue, red and amber light. At high intensity light) as in any well-lit office) nearly 85 percent of patients reported immediate intensification of headache-in almost all colors except green. Burstein and his team found, unexpectedly, that green light actually helped in reducing of headache pain by about 37 percent.
To understand the reason why green light causes much less pain to these patients, the team devised experiments in which they measured exact magnitude of electrical signals generated by the cortex (in the brain) and the retina situated in the eye in response to each color of the light. They found that green light generated smallest electrical signals in both the cortex and the retina.
Next, the team used animal models to depict that the thalamus, area of brain that transmits all information about light coming from the eye to cortex, modifies it in a way that explains why red and blue lights are more painful than amber and the reason why amber is also more painful than green.
“My sincere hope is that migraine patients will definitely be able to benefit from our findings one day very soon,” Says Burstein, who’s also trying to find some way to build a low-cost light bulb with the capability to emit “pure” (narrow band wavelength) green light at very low intensity and smart sunglasses that can block all but narrow band of pure green light. However, he’s very clear that cost of this light bulb, as well as technology, could be astronomical.