My eyes are glowing like Christmas tree lights! I'm off to the left of this picture peeking over the edge of my Sleepypod. When it's dark or getting dark, if I look directly into a light or a flash of light, my eyes shine! All cats' eyes glow at night when a light shines on them. So do the eyes of dogs, deer & other night-time animals. We have a special reflective layer at the back of our eyeballs called the tapetum lucidum.