subject: Are Cats Colorblind? [print this page] Cats have brilliant sparkling eyes and they seem to be alert to even the slightest movement. They can detect the flight of a bird passing the window out of the corner of their eyes. However, one wonders if cats are colorblind or if they can actually see all the hues of the world inside and outside their homes.
Cats are not totally colorblind, but they do not see colors the same way humans do. They can see about one in three colors, so in a way they are like humans who cannot distinguish all colors. We refer to these individuals as colorblind even though they are able to see some colors.
Humans and cats have cone pigments in their eyes that detect certain wavelengths of light. Humans have three cones that allow them to detect green, blue, and red light. Cats have two cones that are sensitive to blue and green light, so are therefore unable to distinguish shades of the color red. These shades may appear to the feline as either grayish or they may be viewed in another color that the animal can see.
The ability to see color is not as essential for cats as it is for humans. Cats are much better at seeing things in dim light, making them good night predators. A cat needs 1/6 the amount of light that humans do in order to distinguish the same movement and shape details. The pupils of the feline eye narrows to a slit in a bright light and opens very wide in dim light. However, a cat cannot see in total darkness just as a human cannot.
In a cat's eye, there is a reflective layer located behind the retina that is called a tapetum. This reflects the incoming light and bounces it off the cones in the eye, allowing the pupil to maximize use of the available light. This is why cat's eyes appear to glow at night, characterized by shiny green or yellow orbs when you look at them. The cat is making the most use of the available light in order to survive in the wild during the night time hours.
Though a cat is not totally color blind, it is not able to see shades of the color red. It will perceive these as gray or as another color that it can see, such as blue or green. The cat does not need this color perception in order to survive because it relies more on its excellent low light vision and other predatory skills.
