People experiencing migraine often avoid light, finding retreat in darkness. A new study led by the researchers from the Harvard Medical School has revealed a previously unknown connection existing between the light-sensitive nerve cells in the eye and centers of the brain that are responsible for regulating mood. These are also a host for the main physical parameters, such as the rate of heartbeat, shortness of breath, fatigue, congestion and nausea.

The effects of light and color in the cases where people were experiencing migraines were tested by the experts. These were undergone on multiple patients, once for those who never experienced migraines, and twice for the patients with migraines, once during an attack, and one between attacks.

It was found that all colors of light eventually triggered unpleasant physiological sensations in patients with migraines, both during, and between attacks. In addition to this, the migraine sufferers reported intense emotional responses, such as anger, nervousness, hopelessness, sadness, depression, anxiety and fear when exposed to all light colors with the exception of green.

Exacerbated headache intensity was observed in participants who perceive light but have no sight as a result of the loss of rods and cones, while in those who lack light perception the headache intensity levels were stable, sue to their optic nerve degeneration. The results showed that the nerves relaying signals from the eye to the brain played a critical role in the discomfort associated with migraine.

According to the published findings, the headache intensity increases with blue, red, amber and white lights, but it showed a decrease in the moment when the patients were exposed to a specific wavelength of green light. As discovered by the experts, this green light activates the neurons in the retina and the brain to a lesser extent than blue, red, amber and white lights do, therefore being less likely to trigger the physiological, autonomic, endocrine and emotional responses of the migraine sufferers.