The Heterochromia Epidemic: A Quick Overview
Among rare eye colours, heterochromia is undoubtedly the best. Technically, heterochromia cannot be classified as an eye color; indeed, the term “heterochromia” refers to two eye colors present in the same person at the same time. Heterochromic individuals and animals have two distinct eye colors. This could mean that someone has either two distinct iris colors or two different colors within a single iris.
It is important to take the time to explore the fascinating science surrounding eye colour, as well as a few famous faces who have heterochromia, as well as how you can achieve the look safely with colored contact lenses.
What is the effect of eye color?
In order to understand how heterochromia occurs, it is necessary to understand the role played by melanin, a brown pigment involved in the formation of eye colour.
It is generally known that melanin plays a major role in darkening our skin and hair. The amount of melanin you possess in your body determines how dark your hair or skin will appear. There is interestingly, this pigment is present in greater or lesser degrees in the irises of all individuals. Thus, technically, everyone has brown eyes. Melanin determines the way a person’s irises reflect color to the outside world depending on the amount of melanin in their eyes.
It is well known that melanin has a great deal of ability to absorb light, and therefore people who have a greater amount of melanin in their irises tend to reflect their dark brown eyes back. People with lighter colored eyes, like blue, green, or grey, simply have a lower concentration of melanin in their iris.
Heterochromia is characterized by one eye having significantly more melanin than the other, or by one eye having significantly more melanin on one side of the iris than the other.
What is the rarity of heterochromia?
There is a recent study that suggests that only about one percent of the global population has heterochromia. Only red and grey are as rare as heterochromia.
There are approximately 80% of people worldwide who have brown eyes. This color is particularly prevalent among people who come from African or Asian backgrounds.
Most people with blue eyes are of European ancestry, although amber, hazel and green eyes are slightly less common. Blue eyes account for about 8% of the global population.
What causes heterochromia?
There appears to be a special mutation that all of these patients share, which is mainly responsible for the inheritance of heterochromia in most cases. However, geneticists do not fully understand how heterochromia heritability works.
Nevertheless, there are some examples where heterochromia may develop as a secondary symptom of a disease or as a reaction to certain medications. Glaucoma eye drops, for example, have been observed to gradually change the color of the eyes over time. If the colour of your eyes suddenly changes, you should immediately consult an eye doctor.
Heterochromia in its various forms
It may surprise you that there are actually three major types of heterochromia. Although all types of heterochromia involve two colors in the eye, opticians often enjoy pointing out a few unique features.
There are two types of heterochromia, the most prominent of which is known as “complete heterochromia.” A person with this condition has two iris colours that differ from one another.
Alternatively, some people have partial heterochromia in which the iris has at least two shades of color. This condition is also known as sectoral heterochromia and may be found on only one or two iris.
A third condition is central heterochromia, which is characterized by two distinct colors in one iris, much like partial heterochromia. As you might expect from its name, however, the center of the pupil is a different shade of color than those around it.
Is Heterochromia Eyes a Dangerous Condition?
The risk of eye diseases associated with heterochromia does not appear higher than for people with other eye colors, however, a considerable amount of evidence has been presented regarding the health benefits and disadvantages of different eye colors. Patients with heterochromia should consider how to care for their eyes based on the color of their eyes.
People with lighter eyes are more likely to develop UV-related damage over time because melanin not only gives off a brown pigment, but also blocks out harmful ultraviolet rays. Despite some doctors’ belief that electronic blue light may be more harmful to people with lighter eyes, the data on this matter remains unresolved.
It does not mean, however, that people who have brown eyes should ignore the importance of maintaining their eyes, just because they have greater UV protection. In fact, a recent study found that people who have brown eyes are more likely to suffer from cataracts than those who have blue eyes. Therefore, whatever your eye colour (or colours! ), always wear UV-blocking sunglasses when you are outside.
How Does Anisocoria Affect the Body?
There is a condition known as anisocoria, which is often confused with heterochromia. Although the eyes appear to appear two different colors, anisocoria is actually caused by differences in the pupils rather than the iris.
Due to the differences in pupil size between the two eyes of the anisocoria patient, the larger eye may appear darker than the smaller eye, depending on how severe the condition is.
As with most cases of heterochromia, anisocoria is usually not cause for concern. There are two possible causes of anisocoria: genetic or direct trauma to the eyes.
It is estimated that at least 20% of all people born in any population have anisocoria. David Bowie, the late singer-songwriter and actor, is most famous for having anisocoria, but he also had heterochromia, which may have added to his anisocoria.
Who Has Heterochromia Among Pop Stars And Pets?
You probably have seen at least one movie star with heterochromia light up the silver screen. Indeed, Robert Downy Jr. has heterochromatic eyes, and is one of the most successful actors in the Avengers franchise.
In addition to Mila Kunis, Benedict Cumberbatch, and Christopher Walken, there are a number of other stars with heterochromatic eyes.
Heterochromia has also been associated with several fascinating historical figures. These include Johann Wolfgang Goethe, Alexander the Great, and Emperor Anastasius I, who were all reputed to be heterochromiatic.
Some breeds of dogs and cats are particularly susceptible to heterochromia, and it is not only humans that can develop this genetic mutation. The Alaskan husky is likely to have the highest frequency of heterochromia among dogs, however Great Danes, collies, and corgis can also be highly affected. The Sphinx and Turkish Angora cats are known for their heterochromia traits.
Useful Tips For Decorative Contact Lenses
Almost anyone can take advantage of heterochromia eyes’ uniqueness and beauty. The color of your eyes can be easily changed with coloured contact lenses, so you can choose between a combination of blue/green, blue/brown or brown/green.
In spite of perfect vision, it is recommended that you have a fitting for colored contact lenses. In addition to providing support and advice on how to keep your eyes healthy and safe, your optometrist will provide you with information about how to take care of your contact lenses.
Wearing lenses while bathing, swimming, or sleeping is not recommended. You should also wash your hands before handling your lenses and throw them away after they have been worn for a certain amount of time.