Our companions have a visual perception of their surroundings and environment that is significantly different from ours. Many false (and real) ideas circulate on this subject. Through the anatomical and histological (cellular structure) of the eye, veterinarians were able to determine how dogs perceive shapes, movements, light, or colors. Focus.
The dog sees in black and white: true or false?
False. The retina consists essentially of two types of visual cells: for simplicity, let us remember that the cones allow the vision of the colors, and the rods allow a vision by low luminous intensity. The study of the dog's retina cells shows that it has fewer cones than man, but more sticks. Thus, the small number of cones and their arrangement on the retina induces the researchers to think that the dog would not distinguish yellow, red or orange. The palette of colors perceived by the eye of the dog is thus actually less wide than that of the man, but they have in no case a vision in black and white.
The dog sees better at night than man: true or false?
True. As seen in the previous paragraph, the dog has more sticks than the man. The rods being the cells of the retina that allow vision by low luminous intensity, it makes sense to think that the dog has better night vision than us. The experience of every dog owner confirms it every day.
The dog has better vision from afar than man: true or false?
False. The dog's ability to distinguish between shapes in general is quite poor. From a distance, if an object is immobile, it will not be able to see it. On the other hand, the dog perceives very well, far and better than any object moving (it is a hunter!). So if you place your dog at the end of a football pitch and put yourself at the other end, it will only join you if you move. Otherwise, he will not see you (unless of course he followed you with his eyes). Experience it!
The dog sees behind it: true or false?
True and false. It is the arrangement of the eyes on the head that determines the width of the visual field. The more the eyes are placed laterally on the skull, the larger the field of view, the better the animal sees behind it. However, in mammals, as a rule, herbivores (prey) have their eyes placed most laterally, which allows them to see the carnivores (predators) arrive even if they are placed behind them. On the other hand, the carnivores often have the eyes closer, which favors the binocular vision, that is to say the vision in relief and in perspective: this favors the hunting. This is the case of the dog, whose field of view is smaller than that of the horse for example. On the other hand, it should be noted that the dog has a wider field of vision than the human, whose two eyes are placed side by side on the face. The man distinguishes better the reliefs than the dog.
Let us remember that the dog sees less well behind him than the horse (or the gazelle ...), but better than the man who sees only in front of him. On the other hand, he sees better the perspectives than the horse, but less well than the man.
The visual capacities of the dog are therefore different from ours, although the overall structure of the eye is very close. A better understanding of how our companions perceive colors, shapes or movements also allows us to better understand their lifestyles and behaviors.
