If you've ever had a migraine, you've probably experienced photophobia, the painful sensitivity to light that sends you scurrying, eyes closed, to the darkest dungeon you can find. In that moment, you're probably wishing for a way to (temporarily) unplug your eyeballs and put an end to the agony. Researchers at The Salk Institute could have a potential answer: A compound that switches off light sensitivity without affecting vision.