What does my dog see? What does my cat see? Does he see the colors? Does he recognize me from afar? How does the cat see so well at night? The vision of animals is very intriguing. We would like to see what they see, we would like to put themselves in their place … Here is what we can tell you to help you understand a little better what goes through the eyes of our pets.
Why don't animals see like we do?
The vision is very varied in the animal kingdom and adapts to everyone's environment and lifestyle, according to their needs and their main characteristic: prey or predator?
The view allows you to move (by flying, walking, running, crawling depending on the species), exploring the environment, avoiding obstacles, escaping from danger …
Good vision aids survival and helps you find food. The predator must be able to see a moving prey well, a gathering animal must see the fruits, a gathering insect must be able to find flowers…
Finally, the view also allows animals to communicate, to recognize their congeners …
The differences of vision between species are based on 4 keys:
- The field of view : it depends on the orientation of the eyes, it determines which part of the environment the animal sees. For example, man sees 180 ° in front of him like predators and gatherers. The superposition of the vision of the two eyes (binocular vision) makes it possible to see in relief.
- The perception of movements : it depends on the ability of the nervous system and the brain to transmit and analyze information. A man distinguishes up to 16 frames per second, some animals can only see 4, others up to 300 (the bee for example)!
- The colors and the light : It’s the photoreceptors in the back of the eye that catch the light and the brain then interprets this message sent by the optic nerves.
- Thevisual acuity : the ability to see more or less clearly or blurry depends on the size of the eye, the shape of the lens, the number of photoreceptors on the retina …
Cones and sticks what are they? It is the cells of the retina that capture light. The cones allow you to see the details precisely and see the colors (blue, green and red depending on the length of colored waves they can pick up). The sticks allow you to see in low light.
The vision of domestic mammals
Hearing and smell are highly developed in mammals, vision is often secondary. They see blurry, distinguish colors less well than we do …
The dog does not see well everything that is more than 5 meters from him, everything will be blurry beyond this distance, we can therefore say that it is nearsighted, however it perceives up to 50 images per second.
We see here that the field of vision of the dog (1st image) is greater than that of the man (2nd image): 240 ° against 180 ° approximately. Images from the book Imagine what the animals see© Edition Seuil Jeunesse, 2013, published here with the permission of the publisher.
Domestic carnivores like cats hunt at dusk thanks to their good vision in the dark. The cat has a lot of sticks among the cells of his retina, much more than humans, and he has a kind of reflecting mirror that retains light (that's why in the dark we can sometimes see the eyes of the cat that shine). He cannot see in total darkness, because he needs a minimum light source, that of the stars is enough at night for example.
The cat, on the other hand, has far fewer cones than humans; Anything over 1 meter away is blurry. The cat is however hypersensitive to movement.
We can see here that the cat (1st image) sees very close details very well, but does not see colors like humans (2nd image). Like the dog, he sees a little like a color blind: he does not distinguish the color red. Images from the book Imagine what the animals see© Edition Seuil Jeunesse, 2013, published here with the permission of the publisher.
The rodents and rabbits are also shortsighted but see very well on the sides thanks to the fairly lateral position of their eyes, which allows them to see their predators even from behind. The rabbit can see almost 360 °.
Here in the 1st image we have the vision of the red squirrel, which is the exception among rodents: it is trichromate and therefore perceives colors like humans (2nd image). Its field of vision is around 300 °. Images from the book Imagine what the animals see© Edition Seuil Jeunesse, 2013, published here with the permission of the publisher.
Good to know : Man is trichromat, that is to say that he can see all the colors (he has cones capable of picking up blue, green and red) while dogs and cats for example are dichromate (they only have two types of photoreceptors: those that capture blue and green).
Vision: one sense among many
Vision is an extremely important sense for humans, but in many other animals it is more secondary.
An animal that does not see well can perfectly adapt to its environment without suffering, because it has other senses much more developed than in humans: smell, hearing in particular …
Losing eyesight is well tolerated in dogs and cats: their vision is less than ours. A dog may have gone blind without its owners noticing because when the loss of vision is gradual, the dog will have developed habit strategies and developed his other senses.