Tag Archives: vision

QQ: Night Vision and Kitty Winks

This week we have a few questions about cats’ eyes and vision!

Q: How can cats see so well without much light?

A: Cats can see in 6x less light than we can. Cats have a wider field of view of 200 degrees, and they have a greater range of peripheral vision, which helps with hunting and avoiding threats.

Cats are crepuscular, meaning they are active at dawn and dusk. There are many creatures, not all benign, that are also active at that time. Their eyes have 6–8x more rod cells than we do, which are more sensitive to light and motion. So, if something is slithering toward them in the gloaming, they will be able to jump out of the way before it strikes.

In addition, cats’ elliptical eye shape, larger corneas, and tapetum, a layer of tissue that may reflect light back to the retina, help gather more light as well. The tapetum may also shift the wavelengths of light that cats see, making prey or other objects silhouetted against a night sky more prominent.

 Anatomy of the Eye

Here’s an image of what a nighttime landscape might look to us (top) vs. how it looks to a cat (bottom).

Night Vision

Image Credit: Nickolay Lamm and Space.com Feline Vision: How Cats See the World Click to see the original, larger image.

More images showing how cats see the world: This Is How Cats See the World

Q: Did my cat just wink at me?

A: Cats have a third eyelid, called a nictitating membrane (AKA haw or, more formally called the palpebra tertia). It is translucent, and moves diagonally from the inner corner of the eye up across the eye to keep it moist and this membrane can also cover the eye and allow them to still see since it is semi-transparent.

Nictitating Membrane

The membrane moves so fast that we rarely catch them blinking with the third eyelid. However, one eye may become drier than the other, or may get a strand of fur or something in it, and that is when they will blink with their regular eyelids. Since this usually only happens in one eye, it appears as if they are winking at us.

So, yes, it’s normal for a cat to blink one eye at a time, but it is not the same as what we think of as winking.

Want to know more? This article at Scientific American has all the details you’d ever want to know about the nictitating membrane.

Q&A: Can Cats Recognize Their Owners in Photos or Videos?

Cats rely a great deal on smell to identify individuals. That’s not the only factor, but it’s a main one. Many photos are also too small, and the idea of having a small, flat piece of paper being a representation of the real 3D world is not a natural assumption.

Cats do recognize faces. In a study published in Journal of Vision, it was shown that cats, but not dogs, can recognize the faces of their owners. They are better at recognizing the faces of other cats, but they can pick out their owner’s face from a line-up of life-sized head shots 54% of the time. That’s pretty good.

Cats also rely on body language, the way a person moves, and other things to recognize individuals. But most of them do recognize their owner’s voice.

A 2013 study published in Animal Cognition showed that cats also recognize their owners’ voices, and can tell them apart from stranger’s voices. Their hearing is much much better than a dogs’ or humans’ hearing (PDF), so they aren’t usually fooled into thinking the sounds from TV, computers, radios, etc. are real when they are adults. But they can still recognize the sound of their owner’s voice, or things like their mother cat’s call.

I had a video of a cat we fostered. Her name was Freya, but we called her Bunny. She was 6 months old when we began fostering her, and it turned out that she was already pregnant. (More on that later.) She was Stiles’s mother. The video had audio of Bunny calling her babies, and also a bit of Stiles’s sister, Cleo. When Stiles heard the video, he ran in, and started pawing at the speakers, and was in great distress because he couldn’t find them. I put him on my desk, and he watched that video 3 times, but I decided it might be doing more harm than good, so I took him in the other room and played with him until he was sleepy.

The video: https://youtu.be/5NwINsxG13c

Our oldest cat, who is 18, is strongly bonded with my daughter. She spends most of her time in my daughter’s room. My daughter went out of town with my sister a few weeks ago, and Kagome wasn’t doing well. So my daughter recorded some videos, and I put on one of her unlaundered shirts, then played the video. Kagome listened very carefully. I played it again, and she started purring immediately.

And finally, two of my cats, Kikiyo and Stiles, will come running every time they hear elephants, whales, or David Attenborough.
kiki-stiles-tv