Most of us have heard of cats having night vision, or at least that they can see very well in the dark. If you have ever wondered if this is really true, then the answer is, yes, they actually do have very good vision at night. The cat needs to be able to see at night due to their predatory instincts. They have a lot of nocturnal instincts; it’s when they do the majority of their prowling and hunting, which means that they need to be able to see in the dark. Cats have a lot of anatomical differences with their eyes that enable them to be able to see at night, although, when the term “night” is used, it really is referring to low light. Cats cannot see in complete blackness, but they can make out images and see a lot more than the average eye, in very low light.
The dynamics of a cat’s eye is, for one, they have elliptical pupils that are vertical in the eye. The elliptical shaped pupil lets it open up larger than the typical round shaped human pupil. The larger the pupil, the more light is allowed in for better vision in low light. Another anatomical difference is a specific membrane in the eye, known as the tapetum lucidum. It is designed so that more light is reflected in the eye and therefore, more light can reach the retina for better vision in the dark. When you look at a cat’s eyes in the dark, you can see the reflectiveness of the eye. This is known as “eyeshine” and is actually light reflecting off of this membrane.
Another factor is the cat’s retina itself. It is designed with more rods than cones, which are the ones more effective for light absorption. The cones absorb more colors, which gives you colored vision, something less needed in cats. All these structures work together to give cats a leg-up on being able to see in the dark so that they can get out there and stalk, hunt, and catch their prey. Of course, the house cat doesn’t really hunt, but they do a lot of their wandering around the house in the nighttime, and now you know how they can – because they can easily see in the darkness to find their way around and get themselves into all the trouble that they do, all while you’re fast asleep.