The authors of a new study say the problem appears to lie with a newly-discovered bunch of cells in the retina.

Researchers from Beth Israel Deaconess Centre an affiliate of Harvard Medical School made the find after pondering why some blind people who suffer from migraines also experience photophobia an extreme sensitivity to light that horribly worsens these headaches.

The work could be a boon for migraine sufferers and opens up exploratory options for drugs that block the pathway enabling a migraine patient to endure light without added pain.