What your dog really sees (no, not black and white)

No, your dog does not see the world in black and white. It sees colours, just not the same ones as you: blue and yellow, yes; red and green, it mixes up. That is why its lovely red ball seems to "vanish" in the grass.

Two cones instead of three

Colours are picked up in the eye by cells called cones. Humans have three types; dogs only have two. Their vision is called dichromatic. In 1989, researcher Jay Neitz (University of Washington) demonstrated it with three dogs, two greyhounds and a toy poodle. In 2013, researchers at the Russian Academy of Sciences confirmed it with eight dogs.

What does its world look like?

Its vision resembles that of a person with red-green colour blindness. Blues and violets look like shades of blue, yellows stay yellow. But red and green turn brown or grey. The green lawn? A dull expanse. The red toy lying on it? An almost invisible blob.

What it sees better than you

Its eye has more rods, the cells sensitive to low light and movement. It also has a reflective layer at the back of the eye, the tapetum, which boosts night vision (it is what makes its eyes glow in flash photos). So dogs see fewer colours, but they spot movement in dim light better.

The right move: blue or yellow toys

For the ball at the park or training exercises, choose blue or yellow toys: they stand out on grass and sand alike. If your dog "ignores" the toy you just threw, it may not be stubbornness: it simply cannot see it.

Frequently asked questions

Can my dog see the TV?

Many dogs react to images of animals or to sounds, but their perception of on-screen colours is limited to blues and yellows.

Do cats see like dogs?

Cats also have reduced colour vision compared with ours, with very good vision in dim light.

My dog bumps into things in the dark: is that normal?

No. Any change in vision deserves a visit to the vet.

Read more: indoor activities for your dog and saving on pet products.

General information. Any vision problem should be examined by a vet.

Sources: Neitz J., Geist T., Jacobs G.H., "Color vision in the dog", Visual Neuroscience, 1989; American Kennel Club; PetMD.