Many animals exhibit “eye shine” — their eyes reflect light and show a different color.  This is very obvious at night.  Brown eyes usually reflect back gray – green.  Blue eyes look red.

Made an interesting observation the other day.  Keno’s eyes are brown.  His right eye barely reflects any light at all — slight gray, but hard to see anything.  His right eye (which is very cross-eyed) reflects red.

Eye shine is known as tapetum lucidum, which in Latin means “bright tapestry”.  Tapetum lucidum is a layer of tissue that is behind the retina.  It reflects visible light back through the retina and allows animals to see well in the dark.  Humans do not have tapetum lucidum.