Eyes are a special organ that is endowed with all living things on the planet. We know in what colors we see the world, but how do animals see it? What colors do cats see and which don't? Is dog sight black and white? The knowledge of animal vision will help us to look more widely at the world around us and understand the behavior of our pets.
Vision Features
And yet, how do animals see? According to some indicators, animals have better vision than humans, but it is inferior in the ability to distinguish between colors. Most animals are seen only in a palette specific to 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 studies have proven that animals see different wavelengths, unlike humans.
Thanks to vision, we receive more than 90% of information about the world that surrounds us. For us, the eyes are the predominant sense organ. It is interesting that the visual acuity of animals in its acuity significantly exceeds human. It is no secret that feathered predators see 10 times better. An eagle is able to detect prey in flight from a distance of several hundred meters, and a peregrine falcon tracks a dove from a height of a kilometer.
The difference also lies in the fact that most animals are perfectly visible in the dark. Retinal photoreceptor cells in their eyes focus light, and this allows nocturnal animals to capture light streams in 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 tapetum. Now let's look at individual species of animals.
Horses
The grace of a horse and its expressive eyes can hardly leave anyone indifferent. But often those who learn to ride a horse are told that approaching a horse from behind is dangerous. But why? How do animals see what is happening behind them? No way - the horse has a blind zone behind his back , and therefore it can easily be scared and buck up.
The horse’s eyes are positioned so that it is able to 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 it sees one image. This animal also has peripheral vision and excellently sees at dusk.
Add a little bit of anatomy. There are two types of receptors in the retina of any living creature: cones and rods. Color vision depends on the number of cones, and the rods are responsible for peripheral. In horses, the number of rods prevails over that of a person, 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, especially the cat family, is significantly different from human. The cat’s pupil is not round, like most animals, but elongated. He reacts sharply to a large amount of bright light narrowing to a small gap. This indicator says that there are a large number of receptor rods in the retina of the eye of animals, due to which they perfectly see in the dark.
But what about color vision? What colors do cats see? Until recently, it was believed that cats see in black and white. But studies have shown that
the cat family distinguishes between gray, green, and blue. In addition, he sees many shades of gray - up to 25 tones.
Dogs
Dogs' eyesight is different from what we are used to. If we return to the anatomy again, then in the human eyes there are three types of cone receptors:
- The first perceives long-wave radiation, which distinguishes between orange and red.
- The second is medium wave. It is on these waves that we see yellow and green.
- The third, respectively, perceives short waves, on which blue and violet are distinguishable.
The eyes of animals are distinguished by the presence of two types of cones, so dogs do not see orange and red colors.
This difference is not the only one - far-sighted dogs see the best moving objects. The distance from which they see a stationary object is up to 600 meters, but the dog’s moving object is already noticed from 900 meters. It is for this reason that 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 the smell and hearing.
Now let's summarize - what colors do dogs see? In this they are similar to color-blind people, they see blue and violet, yellow and green, but a mixture of colors may seem to them just white. But best of all, dogs, like cats, distinguish gray colors, with up to 40 shades.
Cows
Many people believe, and we are often presented with the idea that domestic artiodactyls react sharply to 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 painted or what color they wave in front of their faces. I wonder who will like it if they start waving a rag in front of his nose, sticking, in addition, into the scruff of a spear?
And yet, how do animals see? Judging by the structure of their eyes, cows are able to distinguish all colors: white and black, yellow and green, red and orange. But only weak and blurry. Interestingly, cows' eyesight is like a magnifying glass, and for this very reason they are often scared when they see people suddenly approaching them.
Nocturnal animals
Many nocturnal animals have large eyes. For example, tarsier. This is a little monkey that goes hunting at night. Its size does not exceed the squirrel, but it is the only primate in the world that feeds on insects and lizards.
The eyes of this animal are huge and do not turn in the eye sockets. But at the same time, the tarsier has a very flexible neck allowing him to rotate his head 180 degrees. It also has extraordinary peripheral vision, allowing you to see even ultraviolet radiation. But the color distinguishes tarsiers very weakly, 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 did not use sight, and fly only due to echolocation. But recent studies have shown that they have excellent night vision, and moreover, bats are able to choose whether to fly into the sound or turn on night vision.
Reptiles
When telling how animals see, one cannot keep silent about how snakes see. The tale of Mowgli, where a constrictor with its gaze captivates the monkeys, leads to awe. But is that true? Let's figure it out.
Snakes have very low vision, this is affected by the protective membrane that covers the reptile's eye. From this, the named organs appear cloudy and take on the terrifying appearance of which legends are composed. But the vision for snakes is not important, basically, they attack moving objects. Therefore, the tale says that the monkeys sat in a daze - they instinctively knew how to escape.
Not all snakes have peculiar thermal sensors, but nevertheless they distinguish infrared radiation and colors. The snake has binocular vision, which means she sees two pictures. And the brain, quickly processing the information received, gives it an idea of the size, distance and shape of the potential victim.
Birds
Birds are amazingly diverse. Interestingly, the vision of this category of living creatures also varies greatly. It all depends on what kind of life a bird leads.
So, everyone knows that predators have extremely sharp eyesight. Some species of eagles can notice their prey from a height of more than a kilometer and fall down with a stone to catch it. Do you know that certain species of birds of prey are able to see ultraviolet light, which allows them to find the nearest mink of field mice in the dark ?
A magnificent owl cannot move its eyes, but it is endowed with a very flexible neck, which allows it to turn its head 180 degrees. Parasitically, this predator does not see well in the dark and usually catches prey, guided by hearing.
And the budgerigar living at your place has excellent vision and is able to see everything in color. Studies have proven that these individuals distinguish each other with bright plumage.
Of course, this topic is very broad, but we hope that the facts presented here will be useful to you to understand how animals see.