Sunday, June 12, 2011

Do Cats See In Color Or Black And White?

For years the general consensus was that cats saw the world in black and white, and did not have the ability to perceive color. Recent research has shown evidence that suggests that cats may have a great deal of color vision after all. It's now believed that cats can see different shades of the colors blue and green, but that other colors are not all perceived as we see them. Cats only have two types of cones (photoreceptor cells) in the retina of the eye that are responsible for color vision. There are three types of cones, and cats are missing the cones that correspond to the color red. Humans have all three, allowing us to perceive more color and intensity of color. It's believed that cats have a limited ability to distinguish the difference between reds and greens at all - which is actually a form of color blindness also found in humans.

To answer the question simply - no, cats do not see only in black and white, but they do appear to suffer from a form of color-blindness.

While humans definitely have cats beat in terms of looking at a sunset, their vision in other areas is vastly superior to ours. While they have less cones in their eyes, they have more rods - making their eyes more suitable for perceiving motion than color, and more suitable for seeing at night. Cats are hunters by nature, and their visual skill set provides excellent tools for that. Cats can detect the most minute motions far away, and hone in on them in a way we couldn't even hope to do.

Cats also have fantastic night vision, due to their eyes ability to control brightness to their advantage, needing very little light to see. A cat needs only one sixth of the amount of light a human needs to see. This is achieved as cats have what is called a tapetum lucidum within their eye. The tapetum lucidum (which means "bright tapestry" in Latin) lies just behind, or sometimes within the retina and reflects light that passes through the retina back into the eye, giving that cat a vastly increased ability to see in very dim light. It's this tapetum reflecting light back that sometimes causes a cat's eyes to appear to glow in the dark.

The cat's night vision is also improved by their very large pupils. Cats have slit pupils, instead of the round pupils humans have. This elliptical design serves to protect the cat's eye from too much light, as cats are not 100% nocturnal like most other creatures with very large pupils. The slit shape allows the pupils to dilate and contract more drastically and quickly than a round pupil can, to adjust to different extremes in amounts of light in the environment.

No comments:

Post a Comment