In the daylight, your pup’s eyes might be a pretty shade of chocolate brown or even sky blue, but in the darkness it’s not uncommon for canine eyes to cast a Halloween-worthy glow. So, what’s up with this eerie nighttime glow?
Canine eyes react differently to light exposure than human eyes. The canine eye has a surface between the optic nerve and the retina called the tapetum lucidum, which essentially reflects light back through the eyes like a mirror. The rods and cones in the eye utilize this multiplied light to see better at night. This reflected light also triggers the “glow” we notice in the dark.
A dog’s glowing eyes can appear in all shades including green, blue, orange, yellow, and even red. Red glowing eyes, which might seem especially spooky, are the result of blood vessels reflecting light.