10/30/2026
Friday eye trivia from Out to See, Halloween edition:
Why do a cat's eyes glow when the headlights hit them?
Behind a cat's retina is a mirrorlike layer called the tapetum lucidum. Light that passes through the retina without being absorbed hits that layer and bounces back for a second chance to be detected. That's a big part of why cats can see in light levels roughly six times dimmer than we can. The eerie glow is simply that reflected light coming back out toward you.
Humans don't have a tapetum. The closest we get is 'red eye' in flash photos, light reflecting off the blood rich back of the eye.
Have a safe Halloween weekend, Kailua. Keep the masks vented, keep the kids visible, and keep the costume contacts out of your eyes.