Fun fact some may find disturbing, when you see a red-eye photo you’re actually looking at the inside of the person’s eyeballs. Red-eye in photos happens when a camera flash reflects off the back of the eye, specifically the choroid, a layer rich in blood vessels behind the retina. When the flash is too quick for the pupil to contract, the light enters the eye and bounces off this red tissue, giving you a great picture of the inside of their eyeballs. I hope everyone enjoys knowing that as much as I have.