Probably the biggest difference between cats and humans is in the way they see colors. While humans can see a wide range of colors, cats can only see shades of blue, green and yellow. This is because cats have less cone receptors for color than humans do. Cone cells are responsible for seeing in color, and cat cones do not respond to red-orange or other color spectra. Cats are also nearsighted, so they are not as good at seeing things far away as humans are. This makes it hard for cats to distinguish prey from anything else. Cats also have a limited range of visual acuity, so they can only see things at about 20 feet away.
In addition to being nearsighted, cats have an optical system that works best in low light. Cats have an extra layer of rod cells in their retina that helps them see better in low light. In addition, the reflective layer under the retina, known as the tapetum lucidum, bounces light from the back of the eye out through the retina. This enables cats to see better at night. In addition, cats have an elliptical pupil that can widen in low light and narrow in bright light. This allows cats to focus on objects in their immediate vicinity, but also helps them to pick up small movements in the light.
Cats also have an eerie glow in the dark because of their reflective layer under the retina. This makes cats’ eyes glow in pictures taken with a flash. This reflective layer also helps cats to see in the dark, and it reduces the net visual acuity of their eyes. Cats also have an expanded field of vision, which gives them a better peripheral view than humans. During the day, cats’ eyes are set more on the sides of their head, rather than in the middle. Cats’ eyes also have vertical slits that allow them to focus. This allows them to see the world with one sixth the amount of light needed by humans. Cats can see a great deal of detail at about 20 feet away, but they will likely miss things in the distance.
Cats have a wide field of vision, which allows them to see about 200 degrees. This is about the same as humans can see at about 180 degrees. Cats also have better night vision than humans. They are very active at dusk and dawn. Cats are naturally hunters and so have a strong instinct to hunt at night. As a result, their eyes are designed to help them hunt in the dark. They have reflective layers under the retina, and they have extra rod cells in their retina to help them sense motion in the dark.
Cats can also see ultraviolet colors. Many things in the world have ultraviolet coloration. While humans can see all of the primary colors, including red, blue, yellow and green, cats can only see a limited range of colors. Cats can see shades of blue, green and yellow, but they can’t see shades of red or purple.