Dear Ms. Kitty: My cat Emma sometimes paws at her treats before she eats them, like she can’t see them very well. What do cats see exactly? And what’s with those headlight eyes at night? Signed, Glowing in Gleneagle

Dear Glowing: You’re right; cats do see the world differently than we humans do. Most of us know that cats see better than we do in low-light situations. Experts think cats can see about seven times better than we can in dim light. (Not complete darkness…that’s dark to all of us!)

But it’s also true that cats can’t see objects within about 10 inches very well, like a middle-aged human. That’s why you sometimes see cats touch things before eating or drinking. Their whiskers also give them good information about objects close to their faces.

They aren’t exactly farsighted either, with a range of about 20 feet. It’s all about how and where they find food. Cats don’t have the need to spy prey from hundreds of feet away like a bird of prey, for example.

Hunting needs also dictate the fact that cats can pick up movement faster than we can. Cats are hardwired to see movement in prey, and their bigger corneas and vertical pupils help them do that.

You’ve probably seen Emma’s pupils dilate when she’s excited, playing, stressed or having a little catnip. Our pupils dilate by a factor of 15, but for cats, it’s 135! They are at least ten times better than we are at detecting motion in the daytime.

Cats and humans both have rod and cone cells, the photoreceptors in the retina that convert light to vision. Cats have more rod cells, which also help them see better in low light.

Humans have more cone cells, which help us see color details better and in richer saturation. Cats can see only yellow and blue, not red. This is similar to humans with red-green color blindness. That means red and green may look the same to cats. You may find that Emma prefers blue or yellow cat toys simply because she can see them better.

As cats age, their irises can develop brown or black spots or freckles. This condition is called iris melanosis and, while not usually cause for concern, it’s worth having your vet check out during Emma’s annual checkup.

Her pupils may appear more textured and her irises lacey as she ages. Her eyes can also get hazy, which could progress to cataracts or even glaucoma—another reason to keep up with those annual checkups.

Cats have a third eyelid, known as the nictating membrane. You may have seen this thin film come up over Emma’s eye if she’s not feeling well or is stressed. It’s a good indicator that something could be wrong and is easy to monitor.

Eye shape can also indicate stress. When a cat is squinting or holding his or her eyes shut, that can be a sign the cat is unhappy (along with many other body language factors, like dilated pupils, flattened ears, tucked tail and pulled-back whiskers). The grimace scale can help you assess your kitty’s pain level.

As for those spooky headlight eyes in the dark that some call eyeshine? That’s another feline characteristic called a tapetum lucidum (which fittingly means shining tapestry). It’s a reflective membrane behind the retina that helps cats gather more information in low light…and adds to their mystery. 

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