What do Alexander the Great, Mila Kunis, Jane Seymour and David Bowie have in common? Besides the fact that they are all individuals whose names are well known to many people around the world, all four of them have different colored eyes. In other words, they have heterochromia, a fairly 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?
- Types of heterochromia
- Heterochromia in animals
- Should you worry if you have heterochromia?
- Diagnosis and treatment of heterochromia
- Famous people with heterochromia
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 baby is born, the final color of his eyes is established in the first or 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 heterogeneous, a condition known as iris heterochromia can occur. Heterochromia (from the Greek ἕτερος - “different”, “different”; χρῶμα - “color”) is a different color of the iris of the right and left eyes or unequal coloring of different parts of the iris of one eye.1 It is the result of some excess or lack of melanin in different eyes, when one eye may be less pigmented, the other more. Heterochromia is a fairly rare phenomenon and occurs in less than 1% of the world's population. It can be hereditary or acquired as a result of eye injury or the development of certain diseases. Many people believe that multi-colored eyes make a face unique. If one eye is blue and the other is brown, the difference is immediately noticeable. Seeing that one eye is gray and the other blue is more difficult, and only by looking closely can you tell the difference.
Causes of the phenomenon and its signs
Scientists and doctors note that the cause of discord is a lack or excess of a special pigment - melanin - in the mesodermal, that is, the front layer of the iris. It is this substance that determines the color and pigmentation of human skin, hair, and the shade of a person’s eyes. The pigment may be missing or it may be contained in excess in the iris. At the same time, with discord in the eyes, there is generally an incorrect redistribution of the melanin present in the body. The shade of the iris, by the way, is formed in the very first months of a child’s life, and it will become final only by 1-2 years.
On a note! Heterochromia also includes different skin or hair color options. But in this case we will only consider disagreement.
Typically, heterochromia is a congenital anomaly. But in certain cases, it can be obtained as a result of injuries, the development of a number of eye diseases, including cataracts, due to hemorrhages in the eye tissue, etc. Differences in eyes also form with Fuchs, Waardenburg, and Recklinghausen syndromes.
American film actress and fashion model Katherine Anne "Kate" Bosworth
The main symptom of the pathology is just a different color of the irises. In general, no further deviations or changes in the visual organs are noted. But in some cases (for example, with Bernard-Horner syndrome), patients complain of changes in skin color, narrowing of the pupil, problems with sweating, and changes in the position of the upper eyelid. All these signs are observed only on the side of the body that is affected by the syndrome.
With Fuchs syndrome, clouding of the lens and atrophy of the iris are also observed. The patient may develop and progress cortical cataracts, and precipitates are observed - small whitish inclusions.
Types of heterochromia
Depending on the type of coloration of the iris, several types of heterochromia are distinguished: complete, in which both eyes have a different color (Fig. 1); partial, or sectoral, when the iris of one eye contains several different color shades at once (Fig. 2); central, when the iris has several full-fledged colored rings (Fig. 3). The most common type is complete heterochromia, where, for example, one eye is brown and the other is blue. The second type, partial heterochromia, is in some cases a consequence of inherited diseases, such as Hirschsprung's disease and Waardenburg syndrome.2 In women, heterochromia is more common than in representatives of the stronger half of humanity.
Rice. 1. Complete heterochromia
Rice. 2. Partial, or sectoral, heterochromia
Rice. 3. Central heterochromia
In medical practice, there are known forms of heterochromia that arise as a result of damage to the iris: simple - abnormal coloring of the eye shell with congenital weakness of the cervical sympathetic nerve; complicated - uveitis with Fuchs syndrome (a chronic disease characterized by damage to one of the eyes, expressed by a change in the color of the iris). Some people have developed heterochromia after injury to 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 characteristic of inflammation of the eyeball appear, 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? For congenital heterochromia, medical treatment will not help, but colored or tinted contact lenses can even out the visible eye color. In case of metallosis, eye color can be restored after successful removal of the foreign body, and in case of inflammation of the eye - with complete cure.
Use colored lenses
Changing your image is an exciting experience. It is not possible to realize the intended image if the color of the iris is too bright or dark.
Colored contact lenses are sold for this purpose. They are available with and without diopters. It is recommended to buy CCL after examination by an ophthalmologist. He will determine the diameter, the degree of visual impairment, and give a prescription for purchase.
CCL should not be worn for a long time. Longer than 6 hours is prohibited, as it harms the eyes and may cause hypoxia. They do not interfere with color perception, but make the eyes unnatural. For those with a dark iris, CCLs are suitable, radically changing the color. Those who want to deepen the natural shade - tint.
TsKL will completely cover the natural dark (dark brown, black) color. Tints are not able to cover the dark iris.
CCLs have an opaque pattern that easily covers the natural iris. They have a dark rim that gives expressiveness to the eyes.
CCL is a foreign object in the eye and requires proper handling and care. Having decided to purchase this eye accessory, it is important to familiarize yourself with the rules for cleaning, wearing, and storing contact optics. This is important not only for the safety of products, but also for the health of the visual system.
Heterochromia in animals
In animals, the phenomenon of heterochromia is more common than in humans (Fig. 4). This anomaly can be seen 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 observed in breeds such as the Siberian Husky. Horses with complete heterochromia usually have one brown eye and one white, gray or blue eye, with heterochromia of the eyes occurring in piebald animals. As a rule, complete heterochromia occurs in animals: one eye is blue or gray-blue in color, and the other is yellow, copper or brown. Partial heterochromia among animals is a rarer phenomenon; it is characterized by a partial inclusion 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 cause any complications or inconveniences for the animal. Its presence does not affect visual acuity and light sensitivity, and the pupil reacts to light with a sharp constriction, as in ordinary animals. However, breeding animals with heterochromia is not recommended; it is considered a defect in the breed, although some animal lovers specifically select odd-eyed pets for themselves.
Eyes of different colors. What should you know?
- 7.1 Video: Different colored eyes in people (heterochromia)
On a note! If melanin is unevenly distributed in one or two eyes, or there is too little or too much of it, this leads to a phenomenon called heterochromia.
The specific color depends on what color pigment is in excess/deficit (it can be blue, yellow and brown). As noted earlier, the phenomenon is rare (approximately 1% of the planet's inhabitants) and, characteristically, more often in women than in men. However, no physiological/anatomical prerequisites for such gender “inequality” have been identified.
Eye color, what does it depend on?
Heterochromia is not considered a pathology, since, apart from the external effect (eyes of different colors do not always look attractive), it is not accompanied by any visual disturbances. But this applies only to those cases where the condition is congenital, that is, not associated with concomitant eye diseases.
In most cases, heterochromia is hereditary. In some cases it is caused by blood staining in the iris of the eye
Should you worry if you have heterochromia?
Of course, heterochromia is an anomaly, but its presence does not necessarily mean the presence of hidden health problems. However, there is evidence that heterochromia may accompany 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, gray hair above the forehead and heterochromia. Another example is a disease such as neurofibromatosis, which affects many organs and even entire systems. Externally, it is accompanied by the presence on the skin of many coffee-milky spots, neurofibromas and pigmented hamartomas of the iris (Bream nodules).3 Experts recommend that not only children, but also adults with congenital or acquired heterochromia undergo an annual medical examination.4 If you notice a sudden change in color irises, the appearance of heterochromia, this may be due to health conditions. In this case, you should consult an ophthalmologist who will conduct a thorough examination and identify any problems.5
Diagnosis and treatment of heterochromia
Let us say right away that heterochromia itself is not a disease. However, it can be a consequence of some serious diseases and therefore requires a medical examination by an ophthalmologist. If pathologies are found 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. If the disease is completely cured, eye color can be restored. In case of congenital pathology, it is possible to change the shade only with the help of colored or tinted contact lenses.
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. When asked, the British version of Wikipedia will give you a whole list of celebrities with one or another type of heterochromia.6 Thus, partial or complete heterochromia was noted in the Hollywood actress Mila Kunis: her left eye is brown, her right eye is blue; British actress Jane Seymour: right eye – a combination of green and brown, left eye – green; American actress Kate Bosworth: left eye – blue, right – blue with brown; Canadian actor Kiefer Sutherland has sectoral heterochromia in both eyes - a combination of green and blue in 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 or another type of heterochromia has been compiled. Pictured (top to bottom): 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 of whose eyes was black as night and the other blue as the sky.7 There are many examples of heterochromia among famous literary characters : Woland (“the right eye is black, the left for some reason is green”) from “The Master and Margarita” and Lieutenant Viktor Myshlaevsky from “The White Guard” by Mikhail Bulgakov, tank commander Vasily Semyonov in Janusz Przymanowski’s book “Four Tankmen and a Dog”. Different eye colors always attract 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 [Site]. URL: https://en.wikipedia.org/wiki/Heterochromia_iridum (access date: 09/22/2014). 2 See: Heterochromia // Wikipedia - the free encyclopedia [Site]. URL: https://ru.wikipedia.org/wiki/ %C3 %E5 %F2 %E5 %F0 %EE %F5 %F0 %EE %EC %E8 %FF (access date: 09/22/2014). 3 See: Neurofibromatosis // Neboleem.net. Medical portal [Site]. URL: https://www.neboleem.net/neirofibromatoz.php (access date: 09/22/2014). 4 See: Heterochromia, or People with different-colored eyes // facte.ru. Educational magazine [Site]. URL: https://facte.ru/man/6474.html#ixzz336UHypus (date of access: 09/22/2014). 5 See: What causes different colored eyes? // essilor [Site]. URL: https://news.essilorusa.com/stories/detail/what-causes-different-colored-eyes (access date: 09/22/2014). 6 See: List of people with heterochromia // Wikipedia, the free encyclopedia [Site]. URL: https://en.wikipedia.org/wiki/List_of_people_with_heterochromia (access date: 09/22/2014). 7 See: Alexander the Great // Wikipedia, the free encyclopedia [Site]. URL: https://en.wikipedia.org/wiki/Alexander_the_Great (access date: 09/22/2014).
Olga Shcherbakova, Veko magazine, 8/2014
