In 75 % of cases , people with migraine headaches cannot tolerate light. We call this photophobia The exact idea of this was unknown to the researchers for a long time But a recent study by Remy Barstein, a professor of anesthesia at Harvard Medical School, provides a rough explanation. He says that a part of the signal from the retina of the eye to the optic nerve acts as a factor in this light sensitivity. He performed an experiment where blocking the visual pathway showed that the light sensitivity was no longer felt. He conducted this study on 2 groups of migraine patients, of which one group is blind and the other group is normal He sees that people who are blind but have migraine do not have this problem Because the optic nerve of those who are blind is dysfunctional, the signal that enters the retina to receive light does not work here. From this he concludes that this mechanism relies entirely on the retinal cells that control our normal biological functions, such as sleep and impaired sleep. These retinal cells contain melanospin 7 They then inject a type of dye into the lab's mouse eye for people with migraines. With this dye, they trace the path of this melanospin and see that some brain cells produce electric impulses at this time during migraine pain. He then inserted a small electrode and saw that the light from the light sent an electric signal to the brain cells which were coming and going. He turned off the light and saw that the brain cells were returning to normal This reveals the mystery of why this light sensitivity occurs in migraine pain. Thanks -