Search Results
2 results for “tapetum lucidum”
Is a Cat’s Vision Good or Bad
A cat's visual sharpness is only about one-tenth of a human's - roughly 0.1-0.2, enough to make out objects around 10 meters away and blurry at that. The trade-off comes from the tapetum lucidum, a mirror-like layer that boosts dim light about 40 percent so cats see in one-sixth the light humans need, at the cost of clarity. Cats are nearsighted and built for the hunt: their best focus is about 75 cm, and they track moving prey (around 15-60 degrees per second, like a mouse) far better than still objects. They see blue-to-green but not red, and their wider 250-degree field of view beats our 200.
Why Do Cats’ Eyes Glow in the Dark?
The ancient Egyptians believed cats trapped the setting sun's light in their eyes until morning; the Greeks thought a flame flickered inside. The real reason is a layer called the tapetum lucidum behind the retina. It reflects light back through the retina, giving the light-sensitive cells a second chance to catch it, which is why cats see far better than us in dim light. The glow is usually green or yellow, and many other animals share this trick.