Migraine is a recurring, episodic neurological disorder characterized as a throbbing headache that is commonly associated with a variety of other symptoms such as nausea, vomiting, irritability, and fatigue. There are around 300 million people worldwide who have migraines, and it is estimated that there are almost 20 million migraine attacks happening every day.

Many celebrities and historical figures suffered from migraine, including Vincent Van Gogh, Claude Monet, Julius Caesar, Napoleon, Elvis Presley, and John F. Kennedy, to name a few. The disorder, three times more common in women than in men and affecting mostly people between the ages of 25 and 50, can be triggered by many factors such as anxiety, stress, hunger, sleep-deprivation, hormonal changes (in women), and especially exposure to light.

However, the relationship between light and migraine has always been a mystery for doctors and scientists. A recent study of blind people seems to shed some light on why light makes pain worse during migraine.

Twenty people with little or no vision were involved in the study. The main conclusion from the study was that “photoregulation of migraine headache is exerted by a non–image-forming retinal pathway that modulates the activity of dura-sensitive thalamocortical neurons.” What this means, in plain English, is that there is a relationship between the area in the brain that is involved in migraine pain and some light-sensitive cells in the retina of the eye. However, these are not cells that contribute to vision, since they were still functioning in the eyes of the blind people.

The results of the study help explain why migraine gets worse by exposure to light even in blind people. Even those individuals in the study who are unable to tell if the world is bright or dim felt a stab of pain the moment they stepped outside and got exposed to sunlight. "That is not true for people who have lost their eyes all together," says an author of the study.

There is no cure for migraine, and the study is not likely to contribute to that. However, what the findings of this study can help with is to develop medications that can prevent more pain when migraine patients get exposed to light, which can make a huge difference in the lives of migraineurs who are forced to spend hours and hours in dark rooms every day.