What causes red eye in pictures?!
Question:
What causes red eye in pictures?
Answers:
Light goes through the front of the eye and reflects off the retina, which is red. It's worst when the room is fairly dim and the person's pupils are open wide. Some cameras flash once, and then again to take the picture. The first flash causes the person's pupils to contract so red eye isn't as bad. Or you can move the flash away from the camera so the light strikes the eye at an angle.
Of course you can also use photo editing software to paint out red-eye. Some photo-editing software even has a tool to do it automatically.