“I was 3 or 4 years old. I was playing in the garden when a brilliant,
shimmering light appeared to my left — dazzlingly bright, almost as
bright as the sun. It expanded, becoming an enormous shimmering
semicircle stretching from the ground to the sky, with sharp zigzagging
borders and brilliant blue and orange colors. Then, behind the
brightness, came a blindness, an emptiness in my field of vision, and
soon I could see almost nothing on my left side. I was terrified — what
was happening? My sight returned to normal in a few minutes, but these
were the longest minutes I had ever experienced.”

—Oliver Sacks, from Patterns, a look at visual migraines published just today at the New York Times. Oliver Sacks is brilliant, of course, and the article is well worth your time. If you’re into these things.