Researchers explain how light may exacerbate migraine pain.

The Boston Herald (1/11, McConville) reports that "researchers at Beth Israel Deaconess Medical Center say they've figured out why light makes migraines worse," according to a study published in the Jan. 10 online issue of Nature Neuroscience. The investigators "found that a group of recently discovered retinal cells that travel along the optic nerve to the brain contain neurons that become electrically charged during a migraine." So, "when light is introduced, the activity increases, and the pain is intensified," the study found.
"The team studied 20 blind individuals, all of whom suffered from migraines," HealthDay (1/10, Gardner) reported. Six of the "participants had no light perception at all...no functioning optic nerve," and therefore "experienced no photophobia." Because the other "14 people could sense light and dark and also experienced photophobia," the study authors theorized that the "optic nerve is critically needed in order to produce photophobia or exacerbation of the headache by light."
AFP (1/10), BBC News (1/11), the UK's Press Association (1/10), the UK's Independent (1/11, Connor), the UK's Telegraph (1/11, Devlin), and the UK's Daily Mail (1/11, Macrae) also covered the story.