Why Are Dogs Color Blind?

You have heard it before, dogs are considered to be color blind, but have you ever wondered why dogs are color blind? The truth is, dogs are not color blind in the same sense as humans that are considered to be color blind. They are still able to see certain colors but their vision is not nearly as accurate as a humans. Although they are considered to be color blind, they do not see in only black and white, but the colors they do to see are very limited.

Why are Dogs Color Blind?

Why are dogs color blind? Well, the answer is fairly simple. Dogs' retinas only contain two types of color receptors. Humans have three color receptors. Human color receptors allow us to see blue, green, yellow, and red. However, because dogs only have two forms of color receptors, they are only able to see yellow and greenish blue. This is what limit's a dog's vision.

Another area that vision is different for humans and dogs is with cones and rods. Both human and dog eyes contain rods and cones, but humans have more cones in their eyes. However, dogs have more rods in their eyes. Dogs are able to see better in low light than humans because their eye have more rods. Rods are responsible for low light vision. Dogs can also see better in low light because their eyes contain Tapetum Lucidum. This extra feature within the eyes is basically a reflective surface behind the retina. This special surface reflects the light through the retina, improving their vision. This is often why dogs appear to have a glow in their eyes while in dark settings.

While dogs do have more rods than humans, their vision is limited because they lack adequate cones to see full color. Cones are responsible for seeing colors. Dogs do not have the area of the eye that contains the most cones like humans do. This area is the focea centralis. Because they do not have this feature, their ability to see fine details is also limited.

Vision in Dogs

Dogs and humans vision differs in another area as well. Dogs appear to see just as adequately as humans do because they are better able to track movements. Dogs also have an increased peripheral vision when compared to a human. This allows a dog to have a greater vision field. Despite a dogs inability to see the full color spectrum, and lack of ability to see details, you would never know they have limited vision. Dogs combine their vision with their keen sense of smell and hearing to live active lives without limitations.

References:

"Color Blindness in Dog" DogHealthGuide.org

"Can Dogs See in Color?" DiscountPetMedicine.com