How do our four-legged friends see? To begin with, less colorful than us: dogs can in fact distinguish blue from yellow, but not green from red, which they perceive as shades of gray. Their vision and practice is similar to that of colorblinds. Their eyes, in fact, have only two types of cones, the retinal cells responsible for the perception of colors, while we have three.

Test: Do you understand what your dog says?

dogs, Focus 318 On Focus 318 (on newsstands) Irene Santoni tells how the world seen (and photographed) by Berta, a cross between a husky and a Weimar bracco. | Focus

Contours and movement. Not only: the objects seen by the dogs are a little less defined in the contours: their visual acuity is in fact 4 to 8 times worse than the human one. On the other hand, they see us better in the dark and in the shadows, because in their retina they have many more rods, which are deputies for night vision. In addition, dogs have a better perception of movement.

However, the world from the point of view of dogs is equally rich in information, because they know how to exploit other channels of perception. Starting from the nose: the truffle (or nose) of dogs contains 300 million olfactory receptors, against the 6 million of the human nose.

What a flair! The olfactory information is so much more numerous and accurate than ours. Not only that, in a study published in the Journal of Comparative Psychology it seems that information conveyed by the sense of smell allows dogs to create a corresponding image in the brain .