Eyes are a special organ that all living beings on the planet are endowed with. We know in what colors we see the world, but how do animals see it? What colors do cats see and what do they not? Is vision black and white in dogs? Knowledge about the vision of animals will help us take a broader look at the world around us and understand the behavior of our pets.
Features of vision
And yet, how do animals see? According to certain indicators, animals have better vision than humans, but it is inferior in the ability to distinguish colors. Most animals see only in a specific palette for their species. For example, for a long time it was believed that dogs only see in black and white. And snakes are generally blind. But recent research has shown that animals see different wavelengths than humans.
We, thanks to vision, receive more than 90% of the information about the world that surrounds us. The eyes are our predominant sense organ. Interestingly, the vision of animals in its sharpness significantly exceeds that of a human. It's no secret that raptors see 10 times better. An eagle is able to detect prey in flight from a distance of several hundred meters, while a peregrine falcon tracks a dove from a height of a kilometer.
The difference also lies in the fact that most animals see perfectly in the dark. Photoreceptor cells in the retina of their eyes focus light, and this allows animals that are nocturnal to capture light streams of several photons. And the fact that the eyes of many animals glow in the dark is explained by the fact that under the retina there is a unique reflective layer called the tapetum. Now let's look at individual types of animals.
Horses
The gracefulness of the horse and its expressive eyes can hardly leave anyone indifferent. But often those who are learning to ride are told that it is dangerous to approach a horse from behind. But why? How do animals see what is happening behind their backs? No way - the horse has a blind spot behind its back, and therefore it can easily get scared and buck.
The horse's eyes are positioned so that it can see from two angles. Her vision is as if divided in two - each eye sees its own picture, due to the fact that the eyes are located on the sides of the head. But if the horse looks along the nose, then he sees one image. This animal also has peripheral vision and sees excellently at dusk.
Let's add some anatomy. There are two types of receptors in the retina of any living being: cones and rods. Color vision depends on the number of cones, and rods are responsible for peripheral vision. In horses, the number of rods prevails over that in humans, but cone receptors are comparable. This suggests that horses also have color vision.
Cats
Many houses keep animals, and the most common, of course, cats. The vision of animals, and especially of the feline family, is significantly different from that of humans. The pupil of a cat is not round, like in most animals, but elongated. It reacts sharply to a large amount of bright light by narrowing to a small gap. This indicator says that in the retina of the animal's eye there are a large number of rod-receptors, due to which they see perfectly in the dark.
But what about color vision? What colors do cats see? Until recently, cats were thought to see in black and white. But studies have shown that the feline family is good at distinguishing between grays, greens and blues. In addition, he sees many shades of gray - up to 25 tones.
Dogs
The vision of dogs is different from what we are used to. If we return to anatomy again, then in the human eye there are three types of cone receptors:
- The first perceives long-wave radiation, which distinguishes orange and red colors.
- Second - medium wave. It is on these waves that we see yellow and green.
- The third one, respectively, perceives short waves, on which blue and violet are distinguishable.
Animal eyes are distinguished by the presence of two types of cones, so dogs cannot see orange and red colors.
This is not the only difference - dogs are far-sighted and see best moving objects. The distance from which they see a stationary object is up to 600 meters, but a moving object is noticed by dogs already from 900meters. This is the reason why it is best not to run away from the four-legged guards.
Vision is practically not the main organ in a dog, for the most part they follow smell and hearing.
Now let's sum it up - what colors do dogs see? In this they are similar to color-blind people, they see blue and purple, yellow and green, but a mixture of colors may seem to them just white. But best of all, dogs, like cats, distinguish gray colors, and up to 40 shades.
Cows
Many believe, and we are often told, that domestic artiodactyls react strongly to the color red. In reality, the eyes of these animals perceive the color palette in very blurry fuzzy tones. Therefore, bulls and cows react more to movement than to how your clothes are dyed or what color is waved in front of their muzzle. I wonder who will like it if they start waving some kind of rag in front of his nose, sticking, in addition, a spear in the scruff of the neck?
And yet, how do animals see? Cows, judging by the structure of their eyes, are able to distinguish all colors: white and black, yellow and green, red and orange. But only weakly and blurry. Interestingly, cows have vision similar to a magnifying glass, and it is for this reason that they are often frightened when they see people unexpectedly approaching them.
Night Animals
Many nocturnal animals have big eyes. For example, tarsier. This is a small monkey that goes hunting at night. Its size does not exceed a squirrel, but it is the only primate in the world,feeding on insects and lizards.
The eyes of this animal are huge and do not turn in their sockets. But at the same time, the tarsier has a very flexible neck that allows it to rotate its head 180 degrees. He also has extraordinary peripheral vision, allowing him to see even ultraviolet light. But tarsier distinguishes colors very poorly, like all nocturnal animals.
I would like to say about the most common inhabitants of cities at night - bats. For a long time it was assumed that they do not use vision, but fly only thanks to echolocation. But recent studies have shown that they have excellent night vision, and what's more - bats are able to choose whether to fly to sound or turn on night vision.
Reptiles
Telling how animals see, one cannot keep silent about how snakes see. The tale of Mowgli, where a boa constrictor fascinates the monkeys with its eyes, is awe-inspiring. But is it true? Let's find out.
Snakes have very poor eyesight, this is affected by the protective shell that covers the reptile's eye. From this, the named organs seem cloudy and take on that terrifying appearance about which legends are composed. But sight is not the main thing for snakes, basically, they attack moving objects. That is why the tale says that the monkeys sat as if in a daze - they instinctively knew how to escape.
Not all snakes have peculiar thermal sensors, but they still distinguish infrared radiation and colors. The snake has binocularvision, which means she sees two pictures. And the brain, quickly processing the information received, gives it an idea of the size, distance and outlines of a potential victim.
Birds
Birds amaze with a variety of species. Interestingly, the vision of this category of living beings also varies greatly. It all depends on the lifestyle of the bird.
So, everyone knows that predators have extremely sharp eyesight. Some species of eagles can spot their prey from a height of more than a kilometer and fall down like a stone to catch it. Did you know that certain species of birds of prey are able to see ultraviolet light, which allows them to find the nearest burrows of field mice in the dark?
The magnificent owl cannot move its eyes, but it has a very flexible neck that allows it to turn its head 180 degrees. Surprisingly, this predator does not see well in the dark and usually catches prey, guided by hearing.
And the budgerigar living in your house has excellent eyesight and is able to see everything in color. Studies have shown that these individuals distinguish each other with the help of bright plumage.
Of course, this topic is very broad, but we hope that the above facts will be useful to you in understanding how animals see.
