If we consider the anatomical structure of the eyeball of a dog, then we can see that it, as it were, conventionally, consists of two halves - the upper and the lower.
The upper part is responsible for visual acuity on the background of a dark shade of earth. Behind her photoreceptors is a membrane that has a reflective effect. The light penetrating the dog's eyes turns out to be reflected by this membrane. And as a result - the eerie glow of the eyes at night or in the twilight.
The rods and cones present in the eyes of the animal capture the reflected rays. Thus, the dog's eye gets two rays from one.
The lower part of the eye, more precisely, its retina, has a dark pigment that absorbs and as it extinguishes the excess light. This gives a particular advantage to the pet - the ability to optimally see in conditions of excess lighting.
Night vision in dogs
Everyone knows that cats perfectly see in the dark. But what about the situation in dogs? Dogs do not belong to nocturnal animals, nor to the day, they are somewhere in the middle. If, again, refer to the structure of the eyes, the presence of a large number of sticks is a sign that the dogs see better during the day than at night. However, this number plays a certain role in low light.
In dogs, behind the cones and sticks, there is a layer called tapetum, which contains a reflective pigment. The light that enters the eyes of an animal is almost entirely perceived at the cellular level, so if you compare the night vision of a dog and a person, it is shorter by 3-4 times in a dog.
Difference of sight of a dog and a person
A man, both children and adults, has been concerned for years with the question of what colors do dogs see?
For a long time, US scientists tried to sort out this issue and quite recently were able to prove that our four-legged friends have color perception, although somewhat different from what a person possesses.
And, of course, the role played by the structure of the eyes of the dog. Cones, which are responsible for color perception, in dogs there are, but in much smaller numbers than in humans. In addition, the human eye is much more complex, since there are three varieties of cones in its retina, each of which performs a reaction in its own color range:
- Reacts to long-wave radiation - in the field of its sensitivity red and orange shades.
- It is sensitive to medium waves - we are talking about yellow and green colors.
- The third cones catch a whole range of colors - purple, blue and blue.
In the dog's eye, no cones were found that are sensitive to red hues. This was the reason why dogs did not see much of a difference between the yellow-green palette and the orange and red colors. The same color perception is observed in people with color blindness. For example, what is blue-green for a person may look like a white color for a dog.
Another significant difference between the structure of the human and the dog's eye is that in humans, in the center of the retina, in the region of the optical axis of the eye, there is a “yellow spot” consisting solely of cones. Its presence allows the cones to catch the direct rays of light that are not damaged when passing through the cornea and lens. In the structure of the eyeball of the dog there is no such spot, which affects the fact that the visual acuity of pets is lower by about three times.
Theoretical calculations indicate that if a dog’s vision is checked with an oculist's table, only the third line will be available to its view. Although a person with good eyesight sees the tenth.
Nevertheless, it is impossible to blame the animal for myopia, since scientific studies have found that dogs have a slight hyperopia (about +0.5 diopters). This indicator can be equated to the vision of most people of mature age.
Pet Eye Care
The eyes of a dog are, if not a mirror of the soul, then precisely an indicator of its health. An experienced breeder or veterinarian can tell you if the animal is sick or not. Clean, dry eyes, with a lively shine, without puffiness and redness - this is a sign of a completely healthy pet.
If the eyes are fine, in most cases, they do not require any care. Sometimes secretions may accumulate in the inner corners of the dog's eyes. If their number is insignificant, it is enough to remove them with a piece of gauze or cotton pad. It is not recommended to use cotton wool for these purposes, since its particles can get inside and cause discomfort and even inflammation.
For this treatment, you can use the following liquids:
- boiled water,
- saline solution
- weak solution furatsilina.
Tea leaves, traditional for people, are also suitable, only there is one small nuance - for dogs with light hair, it can leave colored areas.
Features of the organs of vision of some breeds
There are a number of breeds in which the organ of vision, for one reason or another, is a weak point and requires more attention:
- Dogs with a short, flat, attractive face - Pekingese, Chinas, Pugs, Shih Tzu, French Bulldogs and similar dogs. The special anatomical structure of the muzzle leads to the fact that the natural secret from the eyes can flow into the skin folds on the face, thereby causing discomfort, itching and irritation. Such dogs require a more regular cleansing of the eyes.
- Breeds with elongated fur on the face are all varieties of schnauzers, some species of terriers. Flowing down the coat, tears and discharge can significantly worsen the condition of the coat on the face, gluing it together, which leads to entanglement and the formation of tangles. To prevent this, you need to pay more attention to the condition of the eyes and regularly clean not only the eyes, but also the hair on the face.
- Breeds with excess skin and folds in the area of the head and muzzle - Shar Pei, Cocker Spaniels, Basset Hounds and others. Due to this feature, pets of these breeds have a propensity for diseases of the organs of vision, and most often there is a twist of the eyelids. There are two types of disease - inner and outer turning, but both provide the dog with discomfort and possible complications, up to complete blindness. In non-critical situations, simple eye treatment and the use of moisturizers are sufficient. With the exacerbation of the same disease helps only surgery. Feeding the eyelid can rid the dog of further eye problems.
Possible pet eye problems
When ordinary, unremarkable discharge is not the only problem of the eye? If the discharge just became more, but their appearance has not changed, then most likely the pet has blown through the draft. In this case, washing the eyes with the same means as used for normal procedures will help.
It is worth sounding the alarm if the eye secret has changed its color to greenish or brown, its amount has changed significantly and you can smell it. In this case, the animal must be shown to the veterinarian, as all signs indicate a disease of infectious origin.
On the eyelids, there is a noticeable swelling. There may be several reasons, both trauma and a sign of an infectious disease. In any case, the doctor can tell more precisely.
Is the pet trying to avoid direct rays of light, hiding in the shade, moving without its former confidence? This is a signal that he has significant vision problems. And in this case - a vet to help.
Any problems with the visual apparatus of the pet should be solved only by a qualified technician!
What is animal vision?
First you need to answer the question: “What is vision?” For any living creature, this phenomenon is a combination of the eye and the brain. Two elements of the body are interconnected by a multitude of nerve endings, which gives rise to the image itself and its further perception by a certain subject. How our dogs see the world is mainly influenced by the work of their cerebral cortex. It is through it that 75 percent of chiasm passes, which is responsible for the coherence of the work of the entire visual sensory system. Therefore, a dog that has a damaged brain or some part of it may be blind, while having completely healthy eyes. Also, precisely because a dog perceives everything seen only through the brain, it, like a human, can often have optical illusions. Most often they are based on the memory of an animal (for example, the puppy, being small, climbed under the bed, and when he grew up, remembering this moment, he tries again to get where he no longer crawls, and he does not see that he does not climb, for him this distance seems sufficient.)
To begin, consider how the dogs see the horizons, or rather how wide their field of vision. This aspect primarily depends on how the eyes of the animal are planted; therefore, it can immediately be noted that different breeds will have a completely different overview. The location of the eyes determines the binocular field, as well as the side portions that captures the vision. Thus, the general panorama of how dogs see the horizon is 240-260 degrees, of which only 30-60 is the binocular field (in humans, the field of view is 200 degrees, the binocular review is 140). Do not forget that a long dog nose can also be an obstacle to vision. As for animals with a short nose, in most cases their eyes are even more spaced out, which makes their binocular field smaller. A dog in the inspection of something else can interfere with the ears or long hair.
Depth of view of four-legged comrades
Depending on how the dogs see the perspective and the distance, they can calculate their jumps, running speed and step size with a certain accuracy. This quality is extremely important for sports breeds, which need to perform various exercises, exactly falling on all targets and reaching different heights. If the animal has no disorders in the brain and the vision is 100%, then it can be said that the dog perceives depth more accurately than the person. The large pupil makes it possible not only to see better at dusk, but also to focus more precisely on various objects that can be removed to a wide variety of distances. In this case, we note that the side field of view loses its clarity and focus. All items that are in the side view of the dog look very blurry, their size and real position often change.
Usually curious owners are worried about how dogs see in the dark, whether they are afraid of twilight and whether they are not lost in space when the lights go out. So, in complete, pitch darkness, the dog sees almost nothing. However, in the twilight, in the dark, when a person is already difficult to distinguish between all the nearby objects, our four-legged friends still see well both close and in perspective. This is due to the fact that they have a very large iris, and the pupil catches the slightest gleams of light on objects and transmits this signal to the brain. A remarkable fact is that all breeds of dogs have almost the same size of eyes, as in “cleaners” and in Labradors. Also, the sensitivity in the dark is affected by an interlayer called tapetum, which is located behind the retina of the dog's eye. It reflects the light, due to which in the dark the eyes of this animal glow.
A very controversial question is how dogs see colors and whether they distinguish them at all. There is an opinion that our four-legged comrades, our smaller ones, see the world around us in black and white colors, that is, they suffer from color blindness. In fact, practice and numerous experiments, both practical and biological, prove that this type of animal sees a certain range of colors. The main tone, which they distinguish from all others, is blue. They see the traffic light (red, yellow and green) equally, in pale yellow colors. In fact, guide dogs distinguish the traffic light signals by their location, and not by the glow. In turn, these animals distinguish much more shades of gray than man.
Like all predators, dogs react more sharply and quickly to any moving objects, both large and small ones. This is often the answer to the question of how a dog sees a person. While he is sitting still and not moving, the animal may not notice it (this does not mean that the dog thinks that it is indoors alone, just the visual receptors do not fix the person as an object). Similarly, these animals often ignore static objects. But if this object begins to move in space, the dogs will certainly follow it.
When we start moving, our pets react to it, wake up from a light slumber, begin to follow us, as if chasing. We also note that the reaction even to the slightest fluctuation in a dog is much higher than that of a human. They catch even the smallest objects that move in the air, and closely monitor their trajectory (for example, the midge, mosquitoes or even dust particles, which can be seen in the light).
The clarity of view of pets
Now we will not only touch on the visual abilities of representatives of the dog, but also consider how the world looks like for fluffy and cute cats. Indeed, in the structure of the lens of the eye, in the set of cones, which suggest color vision, these two animals have much in common. The difference lies in the sharpness and focus, which we now talk about.
So, how do dogs and cats see color? Almost the same. Both animals have many shades of gray, while they do not notice red, orange, green and yellow at all. Their viewing angle is also wide, much wider than in humans. But with the focus there are significant differences. If the dog sees a frontal angle of about 30 degrees, the image of the cat is completely blurred. Clearly such an animal can see objects at a distance of no more than six meters, and any panoramas are presented to him in the fog. As for twilight and total darkness, the cats here definitely win both in humans and in dogs. Even in the complete absence of light, homemade fluffies perfectly notice objects that are close to them.
Now each owner knows about how the dog’s world sees. Photos of pictures that appear daily to our pets are presented in the article, and you can compare how much more pale, compared to ours, but at the same time, the vast and clear world of these animals. An important point in the vision of dogs is the focus, which allows you to make only one thing extremely clear and expressive, while all the others blur and become insignificant and gray in the eyes of the animal. This allows our pets to track the slightest fluctuations in space and protect us from danger.
How does a dog see the world? Dogs do not see the world as a man sees it. And all because the structure of the eyes of these animals is different from the structure of human eyes. The retina in the eyeball of a dog is divided into two halves, the upper and the lower.
The upper part of the retina provides visual acuity and night vision. The light that enters the animal's eyes is reflected by the membrane behind the photoreceptors, so the dog's eyes glow in the dark with a frightening light. It is the upper part of the view that the dog can see in the dark, whereas in humans this ability is absent. The night vision acuity of a dog is 3-4 times stronger than that of a human.
The lower part of the retina "turns on" in the daytime, and among other things, has the function of a kind of filter that does not let in too bright streams of light and sunlight. Therefore, sunglasses dogs are completely unnecessary, although some enterprising manufacturers and trying to earn this.
The separation of the retina into two complementary parts allows the dog to see well both day and night without night vision devices and sunglasses. And in vain man considers himself the crown of creation - not everything is so simple, there are more perfect beings on the planet.
Most recently, it was believed that dogs see the world in black and white, but scientists have found that this is not the case. In dogs, color vision is also developed, although it may not be as good as in humans. A person on the retina has 3 types of cones for the perception of long-wave, mid-wave and short-wave beams. In dogs, long-wave cones that perceive red and orange colors are absent, therefore they do not perceive long-wave beams. Perhaps, instead of red and orange colors, they see different color shades, perceive everything in a slightly different color. See the photo.
Without noticing red, dogs can distinguish about 40 shades of gray. Такая возможность у них имеется из-за высокой чувствительности специальных зрительных клеток, и особого строения сетчатки – в верхней ее части находится дополнительная мембрана «тапетум», которая, к тому же, улучшает видимость в темноте.
Еще одно отличие строения собачьих и человеческих глаз – у человека имеется центр сетчатки, представляющий собой желтое пятно, поэтому человек может видеть мир в широкой цветовой гамме, со всеми его цветами и оттенками, и при этом фокусировать предметы в зависимости от их удаленности.
In dogs, this spot is absent, the color and light rays from them perceive the surface of the retina, resulting in a panoramic picture of the world. The angle of view in dogs is 250 degrees, and in humans it is 180 degrees. Moreover, this feature depends on the breed and the anatomical features of the animal. So, for dogs with a small nose and a wide muzzle, the viewing angle is smaller, and for dogs of hunting breeds - more.
With regard to visual acuity, and here the dogs have advantages - without using optical devices, they even notice small fixed objects at a distance of 600 meters, and moving objects - from 900 meters.
There are dogs in the visual apparatus and other features. For example, objects that are closer than 35-50 cm are vague for them, animals see better into the distance, therefore they are considered farsighted animals.
As for the statement that the dogs are watching TV. In fact, they are not able to perceive pictures on TV, for them what is happening on the screen is just a chaotic melteshenie. Frames change too quickly, with a frequency of about 50 hertz, the dog does not have time to consider them and at least somehow comprehend. But if the producing enterprises set up the production of television sets with greater frequency, the dogs will also be able to watch movies and cartoons.
Other features of dogs
Dogs not only see differently, they hear and smell this world is not at all like a human being. More developed than in humans, the organs of smell and hearing help them to perceive the world more fully. Canine scientists claim that the scent and hearing of dogs depend on the anatomical structure of the ears - in dogs with erect ears, hearing is better developed, and in dogs with drooping ears, the scent is better developed.
If a person is able to get a lot of information even from a black and white photo, then for a dog it is just a piece of paper smelling of chemicals and reagents. But dogs, especially those who have undergone special training, are able to recognize, catch and even memorize the most delicate smells and their shades.
There are more than 200 million receptors in the dog's nose, whereas in humans it is 50 times smaller. Thanks to these receptors, the scent in dogs is 100,000 times sharper than in humans, they are able to distinguish the most subtle nuances of odors, and sometimes suffer from sharp odors.
The number of receptors in the nose depends on the breed of dog. Dachshunds have the least number of them - about 125 million, most of all German shepherd dogs - more than 225 million. Thanks to a well-developed scent, a dog recognizes its owner at a distance of one and a half kilometers.
Champions in the number of receptors and in instinct are bloodhound dogs, which have 300 million receptors in their noses.
In the photo there is a phlegmatic bloodhound that perceives smells better than representatives of other breeds.
Bloodhounds are able to catch odor molecules 300 hours after its occurrence. Even the US court treats these features of the Bloodhounds with respect, the judges take their testimony as authoritative. So, according to the testimony of the Bloodhound Nick Carter, over 600 criminals were sent to jail in the United States.
Ability to see invisible
Some people attribute to dogs the ability to see entities that are invisible to the human eye - ghosts, brownies and other undead. It is difficult to say how true this assumption is, but the fact that they are capable of predicting the weather and earthquakes by their behavior has long been known. On the eve of earthquakes, dogs start to howl, whine, try to leave the house and call their hosts behind them. And on the change of weather they begin to roll on the ground, however, scientists easily explain this phenomenon by the fact that a dog, like a person, has pain in the joints and aching bones, and thus the dogs try to alleviate their condition.
A number of people associate with dogs: a dog howls - unfortunately in the family of the owners or the death of a neighbor, digs the ground - to illness or even the death of one of the owners, bark at an empty space - trying to chase away the brownie or invisible person.
Dog's language is not always clear to us, and people are accustomed to ascribing supernatural features and properties to everything that is incomprehensible and difficult to explain.
Human relationship with a dog
It is believed that the cat looks down on the person, and the dog - from the bottom up, recognizing the dominance of the owners in advance. Therefore, dogs do not like being hugged - for them, this gesture, which is quite friendly from a human point of view, is another reminder of who is the boss.
But not all breeds of dogs equally build their relationship with a person. Some of them consider the owner and family members to be their relatives, and agree to obey only the strongest and most authoritative of them, as the leader in the pack. Others unconditionally obey all family members, without exception, although they have their own preferences. Therefore, it is important from the first days in the family to place all the accents in the relationship between the dog or puppy, and family members.
How pets see us
Probably every owner would like to know how my beloved dog sees me? Illustrator Kelly Angel thought about how the animal perceives its owner and created on this subject a series of drawings. Often we perceive these relationships as follows: man is the master, and the animal is only a pet. But if you look at it from the other side, then for an animal its owner is not just an average person, but the embodiment of all the best that can be in this world: a superhero, a chef, the most beautiful, successful and real leader.
If you feel that you are useless and useless, then for a dog you are the best and strongest person on earth. Therefore, in moments of particular sadness and insecurity, you can remember what your pet thinks of you and it will immediately become warmer in your soul.
Dogs are not important material values, for the happiness it is only enough for the presence of a number of beloved master. And the surrounding objects are estimated by them only according to what they can be used for. For example, expensive shoes made of genuine leather, soft and well-chewed, therefore, are well suited for scratching teeth.
How to see the colors of the dog
Not long ago, everyone was convinced that dogs see the world in black and white, but American scientists were able to prove that these animals perceive the surrounding space in brighter colors.
In the human eye, there are three types of cones that perceive red-orange, blue-violet and yellow-green parts of the spectrum. In dog eyes, cones that recognize red-orange colors (long-wavelength rays) are absent, which narrows their palette. For a dog, a red apple and green grass will look exactly the same, and traffic lights are also indistinguishable for him. Guides are not guided by color, but by the order of signals. Dogs are likely to see other shades and perceive the world in a different color.
Approximately understand how the dog sees the world, can a person suffering from color blindness (red-green blindness).
To the note: for the dog the most contrasting colors are yellow and blue, which should be taken into account in the process of training (for example, when choosing shells).
Range and width of sight
In addition to rods and cones, there are receptors in the retina that perceive the movement of objects, the appearance / disappearance of light signals and other phenomena. The eyes of these animals only perceive information, and the brain, which analyzes the data coming from the eyes, is responsible for its processing and the formation of a single picture (both eyes look independently from each other, and then the image is combined). Binocular vision is typical for dogs and humans, when a picture is formed on the basis of partially duplicating information from both eyes. Due to this, the ability to distinguish the relief, look into the depth and evaluate at what distance the object is located from the eyes appears.
But unlike the human, in the dog's eye there is no central fossa with cones, providing maximum visual acuity. Due to this, the animal equally well sees the entire surface of the retina. A panoramic picture of the world is obtained through his eyes, so there is no need for him to quickly move his eyes after a moving object.
The absence of this fossa is due to the lower visual acuity of pets. This is especially true for objects near, which are closer than 30 cm from the eyes and look blurry. But at such a distance the scent works well, so even a blurred image can be recognized, it will be a bowl of food or the native face of the host.
Dogs see objects of medium size at a distance of 100-150 meters. However, this distance is not so important, because they, like other predators, react more to movement, including facial expressions and trainer gestures.
For comparison: the dog is able to distinguish a running man at a distance of up to 400 m (and even up to 800 m after special training). If a person does not move, the animal may not notice it even at a 100-meter distance, until it smells by smell.
Particular attention should be paid to the peripheral vision of dogs. Their viewing angle is generally wider (250 degrees) than in humans (180 degrees), while the best visibility for them is narrower. This is also explained by the peculiarities of evolutionary development: the predator needs to look straight ahead and concentrate on the prey, but at the same time not lose sight of the environment.
Features of the breadth of the review also depend on the breed and body structure: individuals with a wide muzzle and a small nose have a smaller viewing angle than representatives of hunting breeds.
Visibility in the dark
Visibility in dark or twilight conditions in dogs is much better than humans. The number and sensitivity of the sticks responsible for seeing in the dark are much larger in their visual organs, so they need less light to determine the size and shape of the object, the speed and direction of its movement. In conditions of limited lighting dogs see the world 3-4 times clearer than a person.
Visual acuity in the dark is also due to the ability to distinguish almost 40 shades of gray due to the presence in the upper part of the retina of the additional membrane - tapetum. Therefore, when objects merge with darkness for people, their pets clearly distinguish each of them and are well oriented on the terrain. How dogs see the world in the dark can be represented by the photo.
Other features of the perception of the world
For people, the eyes give about 90% of the information about the world, while the main friends of a person get an idea mainly through smell and hearing. What is more important for a particular individual, hearing or smell, can be determined by the anatomical structure of the ears:
- with erect ears (like sheep dogs) - hearing,
- with hanging ears (like a spaniel) - smell.
An object that does not make sounds and has no smell for them may go unnoticed. So, a person can get much of the information even from a black and white photo, and for a dog it will be just a piece of paper with the smell of chemicals and chemicals.
But in a dog's nose, over 200 million receptors are located, thanks to which the scent becomes sharper than human 100 thousand times. A well-developed scent allows the pet to recognize and feel its owner at a distance of up to 1.5 kilometers. The exact number of receptors varies with the breed. There are about 125 million dachshunds, while the German shepherd has over 225 million. The champion in this regard is the bloodhound breed with an index of 300 million receptors.
Representatives of this breed are able to feel the molecules of the substance that leaves the smell, 300 hours after its appearance. These features are even used by US courts and recognize the evidence of the Bloodhawds as authoritative during the trial. Thanks to the work and keen scent of the Bloodhound Nick Carter, more than 600 criminals were hidden behind the bars.
line of sight
Everything is relative. We take data on the human field of vision and physical space, visible to the dog's eye. And it really is different. If at us, people, visual perception has the form of a circle, then in dogs this field is somewhat “stretched” to the sides. And do not forget about the axis of the eyes. In humans, the lights are parallel, while in the doggies, these axes diverge slightly. This is obvious even just by elementary inspection. Without any scientific evidence there. Accordingly, a man loses in his breadth of view to a dog uniquely!
Many people believe that a dog needs flair first. But this fact does not fit all dog breeds. First of all, pay attention to the structure of your pet's hearing organs.
This is very important for every dog of any breed. The process of communication for them without body language is generally impossible. For dogs, much will be told by the pursed tail of the familiar mongrels or the screeching of a well-groomed lap dog with a bow between the ears. What about people?
Scientists, having studied the ability to perceive the alternation of television frames by dogs, argue on the intelligent perception of such information by pets. As a result, there are even films that were made specifically for dogs. Imagine, it will take a lot of time and your pet will be able to watch TV along with you!
Until recently, it was believed that a dog's kiss anyway is a manifestation of respect, love, appreciation, affection ... Are you very amused when your doggie licks your face and hands? Do you even boast about it? Here you have to be disappointed. But to what extent, you decide. Scientists, observing wild animals (foxes, coyotes, wolves), stated the fact that the offspring licks their mother’s face, requiring semi-digested food. They decided to bring food to puppies in their own stomach. Towards the parents who returned from the hunt, the puppies run out and start licking their faces, forcing the stomach contents to burp. You, of course, can refute this, considering nonsense. Although in any case, your dog is a great pleasure. Let it remain a welcome ritual. Why not. We do not live in the wild. It is likely that our pets just want to attract attention, enjoy the meeting or express pleasure.
Nowadays, a dog is not uncommon, dressed in a jumpsuit fashionable in straziki. Pretty, right? Well, some pampered pets do not like to walk in bad weather. A man came to the rescue and put a raincoat on himself, while his pet had something with four sleeves.
But if we turn again to the wild nature, then it can be understood that the same wolves are so called "clothes." This is a woolen cover. And in the rain, these animals just hide in a shelter, and not looking for their raincoat.
And imagine that it was the wolf who wore tight clothes that fit both the torso and head? Convenient to him? They impose their opinion, desire, and thus conquer.
Is it because a dressed dog on a leash obediently wags the owner? She imposed a subordinate role and all. Take a walk! It will not get wet in the rain. But is it interested in a dog? Maybe it is important for us?