Contrary to popular belief, dogs cannot see in black and white. Their vision of colors is however different from ours, their spectrum being more limited. This major difference is due to an ocular configuration adapted to the needs of each species.
How does a dog’s eye work?
In the eye, two types of cells are used to capture light: cones and rods. Rods allow you to see in low light and are used for peripheral vision. There is only one type, providing vision only in black, white and shades of gray. The cones, on the other hand, are responsible for daytime color vision. In humans, there are a large number of cones, which allows us to distinguish a wide range of hues and have excellent visual acuity in good light conditions. Dogs have relatively few cones but have a large number of rods, which gives them an advantage for night vision and peripheral vision, but limits their color perception.
Dogs only have blue and yellow sensitive cones, so they can’t see shades of red. They perceive subtle shades of gray and changes in brightness less well than humans. Finally, they tend to see blurry from afar, to varying degrees depending on the breed. However, this visual information is not important for the predators that they are. Their vision is much better than ours in some respects and much more suitable for hunting. They are first of all 10 to 20 times more sensitive to movements, and their field of vision reaches 240 to 250° against 135 to 180° for humans. Also, they see much better at night, although the images perceived by our four-legged friends are quite blurry.