If you’ve ever had the pleasure of serving a cat, you’re probably familiar with the feeling of being woken up in the middle of the night by a “night owl” cat, wanting to yell but holding back. During the day, cats act like they couldn’t care less about you, but once night falls, they’re racing around the house. In the pitch-black darkness, it seems like they can play freely without bumping into any furniture. So, what’s going on? Do cats naturally have night vision?
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Not All “Night Owls” Can See in Complete Darkness
Dr. Caryn Plummer, a veterinary ophthalmologist at the University of Florida’s College of Veterinary Medicine, explains: Whether human or cat, our vision is affected by the amount of ambient light. But there’s no denying that compared to humans, cats are much better at seeing in low light. This comes down to the photoreceptor cells in the retina. Photoreceptor cells are divided into rod cells and cone cells. Rod cells are responsible for detecting low light and non-color vision, while cone cells handle bright light and color vision. These cells convert light into electrical signals, which are then processed by the brain’s neurons and turned into visual images—what we see with our eyes. In humans, the ratio of cone cells to rod cells is about 1:4, while in cats, the ratio is 1:25. This means cats have a much higher concentration of rod cells in their retinas, making them more sensitive to faint light in the dark. According to data from cat protection charities, a cat’s vision in the dark is about 6-8 times better than a human’s. So why did cats evolve this night vision ability? We all know that cats are natural carnivores, and since they cannot produce certain essential proteins on their own, they rely on eating other animals to get those proteins. Many of the species in a cat’s diet are nocturnal or active in dim light. To survive, cats evolved enhanced night vision. While cats are more active at night compared to humans, strictly speaking, cats are not true nocturnal animals. They are considered “crepuscular animals” or “dawn and dusk hunters,” because they prefer to hunt during twilight or dawn. Although cats have evolved impressive night vision, they don’t rely solely on it in the dark. As Dr. Plummer notes, navigating their environment requires the cooperation of all their senses. In addition to their night vision, cats also have incredibly keen senses of smell and hearing, which help them navigate even in the dark.
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Great Vision at Night, But What About During the Day?
As with all things, there’s a trade-off. Cats’ vision is not as sharp during the day as humans’. Dr. Ron Ofri, a professor of veterinary ophthalmology at the Hebrew University of Jerusalem, explains: “In evolution, advantages often come with costs.” For cats, the price of having superior night vision is poorer daytime vision. In bright daylight, a cat’s visual acuity is only about 1/7th that of humans, making their vision blurry in strong light. And since cone cells are also responsible for color vision, Dr. Plummer adds that cats can’t see as many or as bright colors as we do. Humans have three types of cone cells, enabling us to perceive blue, green, and red. Cats, however, lack the cone cells that detect red, so scientists believe cats see a world of mostly blue and gray, with some yellow and green hues mixed in. But for the exact details of how cats perceive colors, we’ll have to ask a cat!
So, the reason your cat ignores you during the day might be because—well, it thinks you’re in a bad mood?
