Have you ever wondered if your dog can see colors? If you have, keep reading to find out how your dog sees the world.
To be able to see colors, an eye needs structures called “cones”. Structures called “rods” are responsible for seeing light and dark. Dogs have fewer cones than us, and only two types of them (compared to three types for a typical human). Cones are “tuned” to a specific wavelength of light. For dogs, one type peaks at yellow-green range of the light spectrum, and the other at the blue-violet range. This means that dogs are dichromatic, and therefore colorblind. Color blindness is a name for any kind of color vision deficiency, but it does not mean that one can’t see any colors at all.
Because of the way their eyes are built, dogs have trouble distinguishing between certain colors. They also see colors less strongly so than humans (because of the smaller number of cones). What we see as red, orange, green, purple, dogs perceive in various shades of grey, or even black (those nice, red and orange toys, for example).
Other important fact about dogs’ eyes is that they have more rods than ours. It allows dogs to distinguish between more shades of grey (two greys very similar to each other for us can be seen as very different greys by dogs), as well as see in the dark better than humans (larger pupils also help in this, allowing more light inside), and to detect movement much better than we do. Dogs also have a larger field of view (250 degrees, compared to 190 for humans). However, they can’t see as many details as we do.
All this information comes from research – both from actually looking at the dogs’ eyes under a microscope, and from watching how dogs behave. But you can safely put “most likely” and “probably” before any of the statements above.
When humans suffer from red-green color blindness, their condition is called deuteranopia. While you may often hear or read that dogs “suffer” from deuteranpia, it’s not the most fortunate use of the word “suffer”. Not seeing some colors is a natural condition for dogs, not an anomaly. It’s like elephants saying that humans suffer from the “trunklessopia” – because they don’t have trunks. In our case, not having trunks is not a medical condition – it’s the norm. In the same way dogs do not suffer from deuteranopia.
Below you can see which colors are affected in various cases of color blindness.
Dogs, most likely, see the world in the colors of deuteranopia, though it’s not the perfect representation of what we know, or what we think we know, about dog vision.