Red-eye in photos is caused by light from the flash bouncing off the capillaries in your eyes.

Red-eye in photos is caused by light from the flash bouncing off the

More from the Human Body Facts niche...

Human Body Facts

You are about 1cm taller first thing in the morning than you are last

Human Body Facts

In an experiment, people were given glasses which flipped their vision

Human Body Facts

You blink your eyes over 10,000,000 a year

Human Body Facts

Amazingly, you can actually smell in stereo – signals from each nostril

Human Body Facts

Only 1/6 of the human eyeball is exposed

Human Body Facts

Albinism affects melanin production; perhaps resulting in extra