Why Do Eyes Glow Red in Pictures?

You know how, when you take a photo, sometimes your eyes might glow red? While there are plenty of apps that can fix it, do you know WHY it happens? Fox shines a light on this mystery.

You will find out about the "tapetum lucidum," which is a layer of tissue behind the retina of certain animals that reflects light. The tapetum lucidum bounces lots of light onto the retina, giving these animals better vision in low-light conditions. 

Related Topics: anatomy, light