It is a common belief that cats have a night vision and are able to see well in the dark. The fact is that cats can not see in pitch black because they need some light in order to see. Yet, they can see better in the dark than humans.
The sight of cats is more advanced than ours – they only need one-sixth of the amount of light that humans do and pick up details a lot better in low light situations. If you are curious what makes them see well in the dark, read on below.
Why do cats see better in the dark?
Cats have larger cornea size than humans. The cornea is the outermost layer of the eye. When light enters the eye, it gets bent by the curved edge of the cornea, which helps in focusing on objects. Cat corneas take over a larger surface area which means their eyeballs are bigger than ours would be at their size.
With large corneas, it means a larger surface area for light to enter. With more light, the easier it is for cats to see and focus, even in what we humans perceive as darkness.
Humans have circular pupils and so do most animals. For cats, they have an elliptical, slit-like shape which plays a huge role that enables them to see in the dark. Their elliptical pupils by comparison to circular ones mean that they can push more light into their eyes in darkness. Their pupils dilate significantly to allow more light into their eyes.
The tapetum is an extra layer of reflective cells in the retina that bounces light back to sensory cells. It is the shiny green reflective surface usually seen in photographs of cat eyes or when we see cats outdoors at night. The tapetum gives cats a higher ability to see through darkness.
Cats have a wider field of view – about 200 degrees compared to humans only having a 180-degree view. This great range of peripheral vision allows them to detect very fast movement in their surrounding.
How do cats see the world?
Although cats have amazing night vision, they have limited colour vision. They see colors but not as varied or bright as humans. They see blue and yellow the best, and red and green fade into grays.
Cats are also near-sighted and cannot focus well on distant objects. They can see 120 feet away, but 40 percent of them cannot see within a foot of their noses.
Why have cats evolved to see so well in the dark?
Many experts believe that the cat’s vertical pupils contribute to their great night vision. Vertical pupils are common in nocturnal animals that use ambush as their way of attacking prey. The shape of their pupil allows for very precise distance gauging and leaping on their prey.
Do cats have a great night vision in the animal kingdom?
Cats have great night vision, but not the best in comparison to other animals. While cats are good at seeing and hunting in the dark, their eyes are not match for some other predators such as owls and eagles.
Cats cannot see in absolute dark yet they have a better night vision compared to humans. Their whiskers also help them get a better sense of their environment and detect any potential obstacles. Also their acute sense of hearing helps them navigate in the darkness.
Image: istockphoto.com / Seregraff