Why do cats' eyes glow in the dark?
Show answer & explanation
Answer: Tapetum reflects light back
They produce their own light — Wrong. Cats don't produce light like fireflies. Their eyes glow because they reflect available light, not generate it. Without any light source, cat eyes appear dark.
Tapetum reflects light back ✓ — Correct! Cats have a reflective layer called tapetum lucidum behind their retinas. It reflects light back through the retina, giving photoreceptors a second chance to detect it. This boosts night vision by up to 6 times! The 'glow' is reflected light, not produced light. Eye color affects glow color!
Special glow proteins — Wrong. Cats don't have bioluminescent proteins. The glow is purely optical - light reflecting off the tapetum lucidum structure. It's a physical reflection phenomenon, not a biological light production.
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