They are people with different eye colors. Eyes of different colors - a disease or a strange feature

Learn how eye color is inherited and why some people have one eye brown and the other green.

It is believed that all children are born gray-eyed, and only after a few months it becomes clear whose eye color the baby has inherited. But how surprised the parents are when it turns out that his eyes are different.

Natalya Beglyarova, a geneticist, expert at the Center for Molecular Diagnostics (CMD) of the Central Research Institute of Epidemiology of Rospotrebnadzor, told Letidor what determines the color of a child's eyes, whether a blue-eyed baby can be born to brown-eyed parents and why the eyes are different colors.

What determines eye color

The color of the iris of the eye depends on the amount of pigment in it - melanin. The more pigment in the iris, the darker the eyes will be.

So, the owners of brown-black eyes have the maximum amount of pigment.

Why are the eyes different colors

Sometimes we come across people with different colored eyes. For example, one is brown and the other is blue or green. This phenomenon is called heterochromia.

It is not so rare, in every hundredth, and means that one eye has an excess or lack of pigment.

Heterochromia can be:

Complete when each eye has its own color;

Sector, when one eye has several areas with different pigmentation;

Central, in this case, the iris consists of several full-fledged colored rings.

How is heterochromia transmitted?

Heterochromia can be of two types: congenital or acquired.

The latter occurs as a result of various injuries (by a fragment of metal objects), impaired innervation (supply of the organ with nerve cells - ed.) or inflammatory processes.

Congenital heterochromia can sometimes be a sign of some hereditary diseases. But most often this is an absolutely harmless feature caused by mutations in the genes that affect the distribution of melanin in the iris.

Mutations, which actually characterize all genetic features, can occur at different stages of development. It depends on this whether it becomes hereditary.

If a mutation occurred in an embryo, for example, at the fifth week of development, when the rudiments of the eyes were formed, then it only concerns the tissue of its eyes, which means it will not be transmitted to offspring.

But the mutation could have occurred at the moment of conception or at an earlier period of development, at the stage of zygote formation, when the egg was fertilized and division began. And if it arose in one of the genes that is responsible for the distribution of melanin, then all cells will already contain this mutation, it will be inherited. And when this child grows up, he may have children with multi-colored eyes.

It is impossible to determine at what stage the mutation occurred, and there is no clinical expediency in this.

How is eye color transmitted?

It is also impossible to predict what kind of eyes a child will have. Eye color is polygenic in nature, that is, it depends on a large number of genes, on variations in genetic sequences.

In recent studies, scientists have identified regions in six genes that can predict the color of the eyes of an unborn child with a high degree of certainty.

Most accurately predicted brown and blue colors. Gray, green are intermediate, it is already more difficult to predict them.

But here again the question of expediency arises. Theoretically, in order to find out the color of the eyes of a child, the expectant mother will have to make a puncture and select the amniotic fluid, which contains the genetic material of the fetus. The procedure is quite risky, it is prescribed only for medical reasons (for example, if a fetal chromosomal pathology is suspected).

It is basically impossible to plan the birth of, say, a blue-eyed baby.

One can only take into account the statistics, according to which in 75% of cases, brown-eyed parents will have a child with the same eye color. There is a small chance that the baby will have green eyes (18%) or even blue (7%).

If one of the parents has blue eyes, and the other has brown eyes, then the child, with varying degrees of probability, can get both father's and mother's colors. The same applies to the owners of blue and green eyes.

If one of the parents is brown-eyed and the other is green-eyed, then dark eyes often “win”.

But genetics never gives absolute certainty. And there remains one percent at which even brown-eyed parents can have a child with blue eyes.

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The color of the eyes of each person is a unique characteristic, which is determined by the degree of pigmentation of the iris. As a rule, both eyes have the same color at their disposal, but there is an abnormal pigmentation, which is called "eye heterochromia".

Such an anomaly can be passed down from generation to generation and appear only over time. Heterochromia is not always a unique eye decoration; it can be a symptom of some pathological processes. In general, this is a rather rare anomaly, occurring in only one percent of the world's population. In most cases, one eye is blue and the other is brown.

What is another name for heterochromia in ophthalmology? Experts call different eye colors in people piebaldism. In women, the anomaly is more common, although there are no anatomical and physiological prerequisites for this. So why do people have different eye colors?

Why do people have different eyes?

Piebaldism develops as a result of a lack or, conversely, an excess amount of melanin in the iris. The more melanin, the darker the eye, and the less, the lighter, respectively.

One of the harmless causes of piebaldism (the so-called discordance) is a genetic predisposition

Other reasons can provoke the appearance of an anomaly:

  • fuchs syndrome. The disease is characterized by inflammation of the blood vessels in the eyes. The process causes blurred vision and deterioration of vision, up to complete loss;
  • injury. Usually light eyes darken, acquiring a brown or green tint;
  • neurofibromatosis;
  • glaucoma;
  • penetration of a foreign body;
  • oncological processes: melanoma, neuroblastoma;
  • hemorrhage;
  • iris atrophy;
  • siderosis - iron deposition occurs in the eyes;
  • a side effect of certain medications, namely antiglaucoma drugs.

This is an acquired ophthalmic disorder, which is characterized by a unilateral lesion. Fuchs syndrome is characterized by a slow course of the inflammatory process in the iris. It is characterized by a change in periods of remission and relapse. Fuchs syndrome is more common in older people.

The disease proceeds slowly, and for a long time it is difficult to detect. An anomaly is usually discovered by chance, perceiving it as a birth defect. An important diagnostic symptom is the slow deterioration of vision in the affected eye and the appearance of floating opacities. The lens becomes cloudy over time, due to thinning, the iris becomes lighter. Perhaps even the development of secondary glaucoma. The affected eye becomes darker than the healthy one.

Fuchs syndrome causes noticeable nodules to appear on the iris. The appearance of spots may indicate the development of atrophic changes in the posterior pigment layer. As the pathological process progresses, the iris becomes faded and dull.


Fuchs syndrome threatens the development of glaucoma and cataracts

Fuchs syndrome does not cause pain, redness and swelling, which is why it goes unnoticed for a long time. The pathological process can be the result of a variety of reasons:

  • inflammation inside the eyeball;
  • neurodystrophy of the vessels of the eye;
  • ocular toxoplasmosis.

Heterochromia can be corrected with colored lenses, and visual acuity with glasses. Conservative therapy includes the use of nootropic, angioprotective, vasodilators and vitamin complexes. Treatment should be aimed at activating trophic processes in the iris. Topical corticosteroids may also be given. In advanced stages, surgical intervention is used.

Prolonged stay in the eye of iron-containing objects can lead to the deposition of organic and inorganic salts. The iron fragment slowly dissolves and permeates the tissues of the eye. The first symptoms of sideriosis can be detected a few months after the introduction of the fragment. Treatment is to remove the foreign body.


Multi-colored eyes may be the result of siderosis

Neurofibromatosis

Signs of the pathological process appear in the first years of a child's life. Boys get sick much more often than girls. Neurofibromatosis may be accompanied by a deterioration in intelligence and the appearance of epileptic seizures. Patients develop spots on the skin of the color "coffee with milk".

Eye manifestations occur in twenty percent of cases and are sometimes the only manifestations of the pathological process. Symptoms largely depend on the location, size, and number of neurofibromatous nodes. In the conjunctiva of the eyelids, they look like cords; in the mucous membrane of the eyeball, neurofibromas look like individual beads.

Varieties

Depending on the causative factors, an anomaly in a person is of two types: acquired and congenital. If heterochromia is associated with damage to the iris, then it is divided into simple and complicated. Depending on the degree of staining of the iris:

  • complete, when one eye is blue and the other is brown. In this case, the iris is colored evenly;
  • sector, or partial. In this case, the iris has several shades. In the iris of one eye, areas painted in different colors are combined;
  • central heterochromia. This means that the iris has several full color rings. This is the most common form in which pigmentation is impaired in the area around the pupil.


People with different eye colors continue to see and perceive colors absolutely normally.

Diagnosis and treatment of people with different eyes

Regardless of the patient's assumptions regarding the nature of the occurrence of heterochromia, the first stage of the treatment process is an appeal to a certified ophthalmologist. An anomaly can be a symptom of serious pathological processes that require early diagnosis and timely treatment. To detect pathological changes in the tissues of the eye, a laboratory and specialized examination is carried out.

If the ophthalmologist finds that the patient's eyes are of different colors, but the vision does not deteriorate and there are no other clinical symptoms, then treatment may not be prescribed at all.

If the eyes have become a different color due to ophthalmic diseases or a violation of the integrity of the iris, then treatment includes the use of steroid drugs. In some cases, the vitreous will need to be removed. Anti-inflammatory, miotic and antibacterial drugs can be prescribed as adjuvant therapy.

Have you met people with different eye colors? Sometimes this can be a hereditary feature of the patient, but in some cases this anomaly is associated with serious diseases that require the timely intervention of specialists. Do not self-medicate, contact a specialist and follow his recommendations.

What do Alexander the Great, Mila Kunis, Jane Seymour and David Bowie have in common? Besides the fact that they are all personalities whose names are well known to many people around the world, all four of them have eyes of different colors. In other words, they have heterochromia - a rather rare condition that occurs in less than 1% of the world's population. What is heterochromia - a disease or an exceptional feature?


What causes heterochromia?

The color of a person's eyes is determined by the iris, or iris. Depending on the content of melanin pigment in its cells and the nature of its distribution, the iris can have a color from light blue to almost black. The color shade of the iris develops during the first months after the birth of a child, the final color of his eyes is established in the first - second year of life, and the amount of melanin determines how dark the eye color will be. The less melanin, the lighter the eyes will be, and vice versa. In some cases, when the concentration of melanin and its distribution are not uniform, a condition known as iris heterochromia can occur.
Heterochromia (from the Greek ἕτερος - “different”, “different”; χρῶμα - “color”) - a different color of the iris of the right and left eyes or an uneven color of different parts of the iris of one eye. It is the result of some excess or deficiency of melanin in different eyes, where one eye may be less pigmented, the other more. Heterochromia is quite rare and occurs in less than 1% of the world's population. It can be hereditary or acquired due to eye injury or the development of certain diseases. Many people believe that multi-colored eyes give the face a uniqueness. If one eye is blue and the other brown, then the difference is immediately noticeable. To see that one eye is gray and the other blue is more difficult, and only by looking closely, you can determine the difference.

Types of Heterochromia

Depending on the type of staining of the iris, several types of heterochromia are distinguished: complete, in which both eyes have a different color (Fig. 1); partial, or sectoral, when several different color shades are presented in the iris of one eye at once (Fig. 2); central, when the iris has several full-fledged colored rings (Fig. 3). The most common type is complete heterochromia, when, for example, one eye is colored brown and the other is blue. The second type, partial heterochromia, is in some cases the result of inherited diseases such as Hirschsprung disease and Waardenburg syndrome. In women, heterochromia is more common than in representatives of the strong half of humanity. In medical practice, there are known forms of heterochromia resulting from damage to the iris: simple - abnormal staining of the membrane of the eye with congenital weakness of the cervical sympathetic nerve; complicated - uveitis in Fuchs syndrome (a chronic disease characterized by damage to one of the eyes, which is expressed by a change in the color of the iris).
Some people have noted the development of heterochromia after traumatizing the eye with an iron or copper foreign body, when it was not removed in a timely manner. This process is called metallosis of the eye, and when it occurs, a number of symptoms appear that are characteristic of inflammation of the eyeball, and in addition, the color of the iris changes. Often with metallosis of the eye, the iris becomes brown-rusty, but it can also be green-blue.
Is it possible to restore the color of the iris? With congenital heterochromia, medical treatment will not help, but colored or tinted contact lenses can even out the visible color of the eyes. With metallosis, eye color can be restored after successful removal of a foreign body, and with inflammation of the eye - with complete cure.

Heterochromia in animals

In animals, the phenomenon of heterochromia is more common than in humans (Fig. 4). You can see this anomaly in cats, dogs, horses, cows and even buffaloes.



Rice. 4. Animals with complete heterochromia

Most often, complete heterochromia occurs in cats with a partial or complete white color, for example, in the Turkish Angora and Turkish Van breeds. According to legend, the favorite cat of the Prophet Muhammad - Muizza - had eyes of different colors. Among dogs, heterochromia is often seen in breeds such as the Siberian Husky. Horses with complete heterochromia usually have one brown eye and a second white, gray, or blue eye, with heterochromia of the eye occurring in piebald animals.
As a rule, animals have complete heterochromia: one eye is blue or gray-blue in color, and the other is colored yellow, copper or brown. Partial heterochromia among animals is a rarer phenomenon, it is characterized by partial inclusions of a color different from the main color of the iris. More often than in other animals, partial heterochromia occurs in dogs of the Australian Shepherd and Border Collie breeds.
Heterochromia is a condition whose gene is inherited, it does not carry any complications and inconveniences to the animal. Its presence does not affect visual acuity and photosensitivity, and the pupil reacts to light with a sharp narrowing, as in ordinary animals. Nevertheless, breeding animals with heterochromia is not recommended, it is considered a marriage of the breed, although some animal lovers specifically select odd-eyed pets for themselves.

Should You Be Worried If You Have Heterochromia?

Of course, heterochromia is an anomaly, but its presence does not necessarily mean the presence of hidden health problems. Nevertheless, there is evidence that heterochromia may be associated with some hereditary diseases. One example of such diseases is Waardenburg syndrome, in which children develop the following clinical signs: congenital hearing loss of varying degrees, a gray strand above the forehead, and heterochromia. Another example is a disease such as neurofibromatosis, which affects many organs and even entire systems. Outwardly, it is accompanied by the presence on the skin of many spots of coffee-milk color, neurofibromas and pigmented iris hamartomas (bream nodules). Experts recommend not only children, but also adults with congenital or acquired heterochromia to undergo an annual medical examination.
If you notice a sudden change in the color of the iris, the appearance of heterochromia, this may be due to a medical condition. In this case, you need to contact an ophthalmologist who will conduct a thorough examination and identify the presence of problems.

Diagnosis and treatment of heterochromia

We must say right away that heterochromia itself is not a disease. However, it can be the result of some serious diseases and therefore requires a medical examination by an ophthalmologist. If pathologies are detected during the examination, the doctor will give a referral for tests and other laboratory tests. Depending on the type of pathology detected, medical or surgical treatment will be carried out. With complete cure of the disease, eye color can be restored. With congenital pathology, it will be possible to change the shade only with the help of.

Famous people with heterochromia

The media pay special attention to describing the appearance of famous people - actors, singers, athletes, politicians, looking for the slightest deviations from the norm. The British version of Wikipedia, when requested, will give you a whole list of celebrities with one or another type of heterochromia.
So, partial or complete heterochromia was noted in Hollywood actress Mila Kunis: her left eye is brown, her right eye is blue; the British actress Jane Seymour: the right eye is a combination of green with hazel, the left eye is green; American actress Kate Bosworth: left eye - blue, right - blue with hazel; sectoral heterochromia of both eyes is present in the Canadian actor Kiefer Sutherland - a combination of green and blue, in the British actor Benedict Cumberbatch; acquired heterochromia after an injury in a fight was noted in the British rock musician, singer and producer David Bowie (Fig. 5). Many other celebrities also have heterochromia.



Rice. 5. A whole list of celebrities with one type or another of heterochromia has been compiled.
On the picture (top down) Cast: Kate Bosworth, David Bowie, Jane Seymour, Mila Kunis

The fact that Alexander the Great had complete heterochromia is mentioned by the Greek historian Arrian, who described Alexander as a strong, attractive commander, one whose eye was black as night, and the other blue as the sky.
There are many examples of heterochromia among well-known literary characters: Woland (“the right eye is black, the left one is green for some reason”) from The Master and Margarita and Lieutenant Viktor Myshlaevsky from Mikhail Bulgakov’s White Guard, tank commander Vasily Semenov in Janusz Przymanovsky’s book Four tanker and dog.
Different eye color always attracts attention, but after reading this article, you will understand that this is most often just an abnormal deviation from the norm, hereditary or acquired.

1 See: Heterochromia iridum // Wikipedia, the free encyclopedia . URL: http://en.wikipedia.org/wiki/Heterochromia_iridum (Accessed 09/22/2014).
2 See: Heterochromia // Wikipedia - the free encyclopedia [Website]. URL: http://ru.wikipedia.org/wiki/ %C3 %E5 %F2 %E5 %F0 %EE %F5 %F0 %EE %EC %E8 %FF (accessed 22.09.2014).
3 See: Neurofibromatosis // Neboleem.net. Medical portal [Website]. URL: http://www.neboleem.net/neirofibromatoz.php (accessed 09/22/2014).
4 See: Heterochromia, or People with multicolored eyes // facte.ru. Cognitive magazine [Website]. URL: http://facte.ru/man/6474.html#ixzz336UHypus (date of access: 09/22/2014).
5 See: What causes different colored eyes? // essilor. URL: http://news.essilorusa.com/stories/detail/what-causes-different-colored-eyes (Date of access: 09/22/2014).
6 See: List of people with heterochromia // Wikipedia, the free encyclopedia . URL: http://en.wikipedia.org/wiki/List_of_people_with_heterochromia (accessed 09/22/2014).
7 See: Alexander the Great // Wikipedia, the free encyclopedia . URL: http://en.wikipedia.org/wiki/Alexander_the_Great (accessed 09/22/2014).

Olga Shcherbakova, Veko magazine, 8/2014

People with an unusual detail of appearance, different eye colors can look very eccentric, and it must be said that this anomaly is quite rare, it occurs only in 1% of the world's population. Different eye colors cause unequal reactions in people, some even find this phenomenon attractive and do not worry about it at all. US actress Mila Kunis won the title of "Sexiest Woman of 2012", although her eyes are of different colors, and quite radically - one eye is blue, the other is brown.

The disease, when the eyes are of different colors, is called heterochromia in the medical literature and is much more common in animals than in humans.

For the most part, the “disease of different eye colors” is not a disease as such, and its owners live a full life, see and perceive colors perfectly, just like people without heterochromia.

This anomaly occurs in both women and men, but according to statistics, it is the beautiful half of humanity that is more prone to heterochromia.

The essence of the phenomenon, or why people can have different eye colors

Eyes of different colors, or, as this condition is also called, heterochromia (from the Greek. ἕτερος - "other", "different"; χρῶμα - "color"), characterize the unequal degree of presence of a coloring pigment in the irises of the eyes. Because of this, different eye colors can be observed in humans and animals.

"Disease of different eye colors" is transmitted through the human genome and, sometimes, manifests itself after many generations. This fact is best known to people who breed purebred animals, because not only people with different eye colors can be carriers of specific genes.

Types and forms of heterochromia. What is the name of the disease when the eyes of different colors are not from birth?

When a person has eyes of different colors, what is the name of this disease? This question is of interest to many, except for the designation "heterochromia of the eyes" there are few definitions. Often this condition is divided into congenital, caused by genetic mutations, and acquired, arising from the disease. Moreover, in the first case, it will be difficult to establish a diagnosis, because the final color of the child's eyes is established by two years.

Why can a person have different eye colors?

The disease, when the eyes are of different colors, can occur in many cases and may well manifest itself in a healthy person, due to damage to the eyes. In this case, it occurs due to the fact that the cervical sympathetic nerve is weakened from birth. And it can also be complicated when heterochromia was caused by some kind of chronic disease that affected one eye. This may also be one of the answers to the question of why the eyes are of different colors.

When a person has eyes of different colors, what is this anomaly called, if the word heterochromia is not enough? It may be metallosis, we will talk about it in more detail later. And now it should be noted that with any type of different eye color, complications are possible. They are more characteristic of the complicated type and can lead to the Bernard-Horner syndrome, when the pupil of the patient narrows, and, in addition, the position of the eye in the orbit may shift. In this case, heterochromia indicates a disease that urgently needs to be treated.

Why do people have different eye colors and can it be called a disease?

One of the reasons why people can have different eye colors not from birth is metallosis. A piece of iron in the eye gets into the eye with siderosis, and copper with chalcosis. In this case, there is pigmentation of the eye, manifested in the acquisition of a green-blue or rusty-brown hue by the iris. In this case, the foreign body must be urgently removed. If inflammatory processes occur after this, it is recommended to prescribe corticosteroids to the patient.

What types of heterochromia do people with different eye colors have?

It is known that with congenital heterochromia it is impossible to restore the color of the iris. And even with an acquired eye color, it has a chance to return to its original color only if such a condition has arisen as a result of a foreign fragment, that is, in the case of a change in the iris during metallosis.

Different eye color in people: what is the name of its variety?

Types of heterochromia are classified according to the degree of staining of the iris: complete, sectoral and central.

  • Full - both eyes of different colors. The most common is the type in which the eyes are brown and blue.
  • Sector - the color of the iris includes several different shades.
  • Central - the presence of several colored rings at the iris.

In addition to pathological cases of acquired heterochromia, the disease should not be feared - it does not at all affect the vision and human health in general.

A noteworthy fact: women are more likely to "get sick" with heterochromia than men. Complete heterochromia is generally more common than partial heterochromia.

Different eye color in people: what is the name of this condition if the disease is acquired

Sometimes people with different eye colors complex because of their "ailment". In order to hide their unusual feature, they resort to the use of contact lenses: with well-chosen shades of lenses, the color of the irises can be evened out and the colors of the right and left eyes can be identical.

However, in fact, there is no reason to be ashamed of this unusual appearance. Proof of this thesis can serve as examples of celebrities such as Jane Seymour, Michael Flatley, David Bowie, Simon Pegg, Mila Kunis, Henry Cavill, Kate Bosworth and Alice Eve. These people, despite their non-standard appearance, were able to achieve success and live with different eye colors, making it their highlight.

According to legend, Alexander the Great himself suffered from heterochromia. Different eye colors symbolized the strength of nature and the extraordinary mindset of the great commander.

An example of heterochromia in literature can be Tristan from legends, lieutenant from the "White Guard" Myshlaevsky and Woland from the novel "Master and Margarita" by Bulgakov - "The right eye is black, the left one is green for some reason."

What is the name of the disease when the eyes are of different colors: heterochromia in history

Interest in why people have different eye colors arose even in the distant past. However, then medicine was not yet developed enough to explain the reasons for such a phenomenon as eyes of different colors, and to tell the masses what it is called. Therefore, unable to find an answer to the question of why a person has a different eye color, people from the common people, having a mystical mindset, considered heterochromia to be a manifestation of something supernatural.

In ancient times, people with different eye colors evoked almost superstitious fear in those around them. They were proclaimed "spawn of the devil", "sorcerers" and attributed all the troubles happening around to their account. Parents of children with eye heterochromia were suspected of having connections with evil spirits and black magic. Some, at the sight of a person with unusual eyes, even began to read special prayers and conspiracies so that they would not be in trouble or the evil eye.

Superstitions about people with unusually different eye colors have survived to this day. For example, about the fact that one cannot be at enmity with a person with multi-colored eyes, because an unknown force protects him from evil intentions and evil thoughts directed in his direction will return to the address back. And the owner of this power, most likely, does not use it consciously and is completely unaware of it.

In addition, there are beliefs that ladies with heterochromia are prone to a revelry lifestyle, but, having met “their man”, they turn into trustworthy and faithful spouses.

Heterochromia in animals

A person has a different eye color, as they say - with such a request, people often turn to search engines, and subsequently learn a lot about our smaller brothers. Uneven eye color, or, as this phenomenon is called, heterochromia, is a phenomenon that affects not only people, but also animals. Moreover, in the latter, this phenomenon is much more common.

Cases of complete heterochromia come across much more often than sectoral.

Different colors of irises - often one eye is blue - can most often be observed in cats. Moreover, the most likely cases of heterochromia are in their representatives with a white color - both complete and partial. As mentioned in the legend, the favorite cat of the Prophet Muhammad was Muizza, who had multi-colored eyes.

Heterochromia is most common in Turkish Angoras and Van cats. Among dogs, Siberian Huskies are the most prone to heterochromia. And Australian Shepherds and Border Collies sometimes have cases of partial heterochromia.

Although many people like the appearance of animals that have different, unusual-looking eye colors, it is noteworthy that breeding animals with heterogeneous eyes among breeders is not encouraged - this is considered a marriage of the breed.

However, be that as it may, among livestock breeders in the conditions of modern society, people with different eye colors are perceived quite normally, their peculiarity has long been something unacceptable, and if you have such an outlandish external feature from birth, you should not hide it and to be shy.

In the event that heterochromia suddenly manifested itself in you or your loved ones, although such a phenomenon had not been observed before, you should consult a doctor to diagnose and treat possible diseases that could cause a change in eye color, because the question of why people have different colors eye can find many answers.

Most often, we pay attention to the eyes when we get to know someone. No wonder they are called the mirror of the soul. And, of course, we immediately notice their color. Unusual, bright shades of the iris always attract attention. We are used to the fact that the left and right eyes are the same color. But it happens that they are different, for example, brown and green.

Our iris has several primary colors: brown, gray, blue, blue, green, black, olive, amber (walnut). The most common eye color on earth is brown, as its carriers are representatives of two large races that make up the main population of the planet - Negroid and Mongoloid. The rarest color of the iris is green, found in only 2% of the inhabitants of the Earth. There are also various variations, such as turquoise or emerald hue. But there is another rare category of people who have eyes of different colors. These can be such options: blue and brown, green and gray and others. A similar anomaly is called heterochromia, it occurs in only 1% of the population.

What is eye heterochromia?

Heterochromia - a different color of the iris in the left and right eyes, or a heterogeneous color of the iris in one of them. Its tone is determined by the concentration and distribution of melanin in the anterior (mesoderm) layer. In the case of heterochromia of the eyes, this pigment is either not enough, or, conversely, it is present in excess.

In the vast majority of cases, this is a congenital anomaly, and only sometimes (for example, with cataracts, eye trauma, hemorrhages in the tissues of the eyes, Fuchs syndrome, and for other reasons), melanin pigmentation can be disturbed.

Acquired heterochromia can be corrected with surgery, but congenital heterochromia cannot be cured. This disease also has various forms.

Types of eye heterochromia in humans

This pigmentation disorder also has several varieties that differ visually, and also have different causes and consequences.

Complete heterochromia

The most common type is when a person has two evenly colored irises of different colors. The most common variations are a combination of brown and green, brown and blue. This is a congenital feature that does not threaten the danger to the organs of vision. With it, a person sees as well as people with the same color eyes.

Sector heterochromia (partial)

It is caused by staining one of the eyes in different tones. With this form of heterochromia of the iris, there can be any number of options: in half, in quarters, there are wavy borders (a rare case). This is due to the uneven distribution of melanin during the formation of color in the first six months of life.

Heterochromia central

With this deviation, several pronounced rings of different colors can be distinguished. It looks quite original, and some do not even suspect that they have a rare anomaly of iris pigmentation, being proud of their unusual eyes.

Metallic heterochromia

A rare species caused by mechanical damage. Occurs when metal particles (bronze, copper) enter the upper layer of the iris or sclera. Such a foreign body a few microns in size is insensitive to the eye. Over time, the iron element, being in a humid environment, begins to oxidize and leads to the formation of a pigment, usually a rusty green or light green shade. Even when the scale is removed, the phenomenon does not disappear. Usually this type of anomaly occurs in people associated with the production of metals.

Heterochromia in animals

Almost all fauna, except for birds and reptiles, is subject to this unusual phenomenon. Among domestic animals, it occurs in black or white cats, in dogs only of certain breeds, for example, huskies or malamutes. Unlike heterochromia in humans, animals have only one type of this disorder - complete, sectoral or central are absent.

What can threaten eye health with heterochromia?

The amount of melanin in the iris, of course, in no way can affect the quality of vision. But there are cases when a change in pigmentation is caused by a disease, for example, Fuchs syndrome (which can lead to the development of cataracts or glaucoma), siderosis or chalcosis (copper salts entering the iris).

If you notice a change in its color, then this is an occasion to consult a doctor to find out the reasons. This fact indicates that some kind of violation has occurred in the work of the body, and this is only an indicator. With congenital heterochromia, nothing threatens the eyes.

Heterochromia of human eyes: how to treat?

We must say right away that if this anomaly is congenital, then it cannot be treated and corrected. With the help of the operation, you can only get rid of the defect acquired due to any causes of this defect. In all other cases, there is a high probability that you will restore the color of the iris, but this, again, depends on the cause. With the metallose heterochromia mentioned above, it will no longer be possible to correct it. Despite this, many people consider this feature even piquant and take pride in being different from the rest. Particularly unusual and interesting is the central heterochromia or sector.

Many celebrities are also not shy about heterochromia. For example, Mila Kunis, Mila Jovovich, Demi Moore and other famous Hollywood stars have eyes of different colors and believe that this unusual fact to some extent even contributed to their popularity, attracting attention. For filming, they use the means of contact vision correction, and the rest of the time they feel great.

Contact lenses for the correction of heterochromia

The easiest and safest method to correct this violation is to use modern decorative optics for this. Manufacturers of ophthalmic products offer a huge range of contact tinted and colored lenses with which you can hide this defect. Some people with complete heterochromia (for example, one eye is blue and the other is brown) buy models of the colors they are looking for and change the iris in any way they want. If at the same time a person has myopia or hyperopia, then he can purchase lenses with the appropriate diopters. With good vision, you can simply select the 0.00 option with zero optical power.

So, heterochromia - a congenital disorder of the pigmentation of the iris - does not threaten any health consequences if it is not the result of any internal diseases or mechanical damage. People with this disease themselves have different attitudes towards it. Someone considers this a piquant feature and does not hide it, someone wears decorative lenses to hide different eyes. But congenital heterochromia of the iris shell can be called rather a rare, unique gift of nature. Many people born with it are gifted, creative individuals, and the above example proves this.