Cats Don't Need Sunglasses at Night
Have you ever noticed that when you put a treat on the floor in front of your cat it takes them a minute to “see” it? But when you watch a nature program, a common house cat pounces on a mouse in the dark as if they were wearing night vision goggles? A cat’s vision is a unique phenomenon as they have terrible vision for some things, yet exceptional for others.
The visual system of a cat allows them to see in low light conditions and detect small movements. The shape of the cells in their eyes makes this possible. Instead of having “cone” cells, they have a higher number of “rod” cells, which makes them more sensitive to light but also means they have poor color vision compared to humans.
Cats have a slit-shaped pupil that changes size quickly. This allows their eyes to adjust the amount of light entering the eyes. They also have a reflective layer in their eyes called the tapetum lucidum, which enhances their night vison by reflecting light back through the retina. This feature of a cat’s eyesight allows them to hunt at night and is an evolutionary adaptation considering their prey mostly compromise of small rodents that mostly come out at night.
While cats can see colors, their color vision is nowhere near as developed as humans. We have three types of color-detecting cone cells in our eyes, but cats have only two types of cones limiting their color range. Cats are dichromatic, meaning they can distinguish between shades of blue and green, but they have difficultly perceiving red and green. Their eyes are more sensitive to short and medium wavelengths of light, which correspond to blue and green better than colors like red or orange. So, while cats can see some color, their vision is highly adapted to detect motion and contrast, which is more important for hunting and tracking their prey.
A cat’s vision is at its best with objects within a few feet of them. Their vision is not adaptive for extremely close proximity or distance and is more developed to fit their predatory needs. Overall, cats are highly adaptable and compensate for visual limitations by using all their senses to detect prey. Their unique ability to see in poor light provides them with an important visual advantage as a predatory animal.