Rarest Eye Color in Humans
This is one of those questions that seems like it should have an easy answer when it really doesn’t. In fact, there is some debate over what the rarest eye color actually is. This is partly because "rare” itself can be a relative term, since one eye color might be very rare in a certain part of the world and extremely common in another.
Though hard scientific evidence is hard to come by, we can say with certainty what some of the less common colors are.
What Is the Rarest Eye Color?
Eye colors from most rare to most common:
• Black (no eyes are true black, just very dark brown)
Though the scientific research is lacking, it is very likely that green is one of the most rare eye colors worldwide. It's commonly quoted that only 2% of the world’s population has green eyes, though it’s difficult to determine where that number came from.
Even if the number is accurate, 2% of the world's 7.3 billion people is 146 million. This is roughly the population of Russia. That's not to say that green eyes aren't special, because they are! It just depends on where you happen to be. In most parts of the world, almost everyone has brown hair and eyes, with green being very rare or absent altogether.
Green eyes are sometimes confused with hazel eyes, which have both brown and green in them. To tell the difference, go into natural lighting (outside during the day), and look at your eyes compared with someone you know to have green, hazel, or brown eyes. The difference should be clear between them.
Where Do Green Eyes Originate From?
Green eyes are most common in Northern and Central Europe though they can also be found in Southern Europe as well as Western Asia. As was mentioned earlier, brown hair and eyes are dominant in most regions, though there are several countries where it is actually more common to have green or blue eyes than brown eyes.
For example, in Ireland and Scotland, 86% of the population has either blue or green eyes, and in Iceland, 89% of women and 87% of men have blue or green eyes. Among European Americans, green eyes are most common in people of recent Celtic or Germanic ancestry. Green eyes also tend to be more common in women.
Even though they're most common in Northern and Central Europe, people of any race can have green eyes.
Celebrities with Green Eyes
- Emma Stone
- Amanda Seyfried
- Clive Owen
- Jon Hamm
- Eddie Redmayne
- Kate Middleton
- Gael Garcia Bernal
Violet and Red Eyes
This might be disappointing for some, but true violet or red-colored eyes do not occur naturally in humans. Some eyes, however, can appear to be violet under certain lighting or makeup conditions.
Elizabeth Taylor is famous for her violet eyes, though in reality she just has very blue eyes that can look violet depending on the lighting. She does, however, have a row of double eyelashes, a rare genetic mutation.
People with albinism, a condition that causes a complete lack of or very low levels of pigment in the skin, hair, and eyes, sometimes appear to have violet or red eyes. This phenomenon is explained below.
Also Very Rare: Amber Eyes
True amber eyes are extremely rare—they are at least as rare as green eyes or perhaps even rarer. Most people have only seen a couple of amber-eyed people in their entire life.
Amber eyes are completely solid and have a strong yellowish, golden, or russet and coppery tint. They can also contain a small amount of gold-ish gray. Some sources say that this could be due to the increased presence of a pigment called lipochrome (also known as pheomelanin).
Amber eyes are often referred to as wolf eyes because of the strong golden and yellowish color with a copper tint similar to that seen in the eyes of wolves. Besides wolves, amber eye color can also be found in other animals, like dogs, domestic cats, owls, eagles, pigeons and fish.
The Difference Between Amber and Other Eye Colors
Amber eyes are different from hazel eyes because they do not contain hints of brown, green, or orange. While hazel eyes might change color or contain flecks of red or gold, amber eyes are always a solid gold hue.
In poor lighting, it's easy to mistake someone with amber eyes for someone with hazel eyes. In natural lighting, however, you’ll see that hazel eyes tend to have two very distinct colors within the iris. They are often brown and green, and contain speckles and mixed hues.
Celebrities with Amber Eyes Include:
- Nicole Richie
- Nikki Reid
- Evangeline Lilly
- Darren Criss
- Rochelle Aytes
- Joey Kern
Contrary to popular belief, true black eyes do not exist. Some people with a lot of melanin in their eyes might appear to have black eyes depending on the lighting conditions. This is not truly black, however, but simply a very dark brown.
The Science Behind Eye Color
Eye color is more complicated than it might seem, as it's determined by a wide range of factors and can depend to some extent on circumstance, especially lighting.
Eye color is determined by:
- Amount and type of melanin in the colored part of your eye called the iris
- The density and composition of the stroma, a thin tissue in your iris
- Lighting conditions (especially for people with light-colored eyes)
Eye Color and Genetics
Genetics determines how much pigment is present in the iris of your eye. Up to 16 different genes play a role in determining eye color though there are two main genes that have the most influence.
How Melanin Affects Eye Color
Melanin is the most common pigment, and it is found in the eyes, hair, and skin. There are several types of melanin, including pheomelanin (which looks more red and yellow) and eumelanin (which tends to look brown and black).
You might have noticed that there is no blue or green pigment mentioned, which means there is no green or blue pigment ever present in the eye. There is only one kind of pigment, melanin, and its derivatives. So how can a pigment that only produces shades of brown create eyes that look green or blue?
While the first half of eye color has to do with what's already in your eye, the other half has to do with what goes into it: Light!
How Light Affects Eye Color
Your iris has two layers, a front and a back one, and in between those is a thin layer of tissue called the stroma, which has proteins in it (namely collagen). This will become important later.
Everyone has some kind of pigment in their iris, which usually includes a layer of melanin on the back of the iris. The only exception to this is for some people with albinism, who completely lack pigment in their iris.
So, technically speaking, everyone (cases of albinism excepted) has the same eye color. The difference comes with how it's perceived, which is due to the amount and type of melanin in the front layer of the iris and how light interacts with it.
Melanin Content and Eye Color
Melanin Presence on Front Layer of Iris
Melanin Presence on Back Layer of Iris
Dominant Pigment Type
Even less than blue
More than blue eyes, less than brown
More than green, less than brown
Pheomelanin and Eumelanin
Red or Violet
None or extremely little
None or extremely little
Biology Behind the Color: Eye by Eye
Blue-eyed people have no or little melanin on the front layer of the eye, so as light goes through the eye, it hits the back of the iris and then reflects out. As it goes through the stroma, the presence of proteins causes blue light to scatter, which makes the eye look blue.
This phenomenon (the scattering of light by particles much smaller than the wavelength of radiation) is called Rayleigh scattering, and it's the same reason the sky appears to be blue.
Unfortunately, we don’t really know why people have gray eyes. There are, however, some theories on where gray eyes come from:
- Gray-eyed people could have an even smaller amount of melanin in their eyes than blue-eyed people.
- They could have a different composition of the stroma that causes the light to scatter differently.
Brown-eyed people have melanin in both parts of their irises, so the effect of the light-scattering cannot be seen. The eyes appear darker because more light is absorbed, and variations in color and shade of brown come from the amount of melanin present.
The front iris layer of green-eyed individuals has only a small amounts of melanin which tends to be the red or yellowish pheomelanin. Since the melanin concentration is very low, the light scattering effect gives off a blue color, which mixes with the yellowish color of the pheomelanin, making the eye look green.
Amber eyes get their color from the increased presence of lipochrome (pheomelanin) in the iris.
Red or Violet Eyes
People with albinism are often considered to have violet or red eyes. However, the truth is a little more complicated. Albinism is a condition that causes people to have a lack of pigment in their hair, skin, and eyes. Since people with albinism lack pigment in their iris, light can bounce off the back of the eye and exit the eye.
The light usually reflects back red because of the blood vessels at the back of the retina. Eyes can look violet when this red color combines with the bluish color of the iris that results from a lack of melanin, and the aforementioned light-scattering effects.
In fact, the reason the eyes look red is the same reason you might have red-eye in a photograph, which results from light reflecting off the back of the eye and passing back out through the iris. In normal eyes and lighting conditions, light cannot exit the eye like this.
Why is the Sky Blue (Same Reason Eyes Are Blue)
Why Eye Color Appears to Change
Many people with blue, green, or hazel eyes commonly notice that their eyes change color depending on:
- What they’re wearing
This is because blue and green eyes get their color from the quality and quantity of light, not from pigment.
Thus, different lighting conditions will change the quality of the eye. Mood can change the size of the pupil, which might make the iris appear to be a different color. The quantity of melanin is not changing, but simply the way that the light is reflecting and scattering through the iris.
Can You Change Your Eye Color Naturally?
A baby's eye color can change in the first couple of years. After that, the eye color will remain the same and the only way to change the appearance of your eye color is through makeup, clothing, lighting, and color contacts.
Putting honey in your eyes will not change your eye color permanently, though it could cause you to go blind. The reason some people see their eye color change from honey is due to the inflammation of the cornea as it tries to remove it from the eye.
Can I Find Out What My Child's Eye Color Will Be?
Unfortunately, it's impossible to predict with certainty what a child's eye color will be. In fact, scientists still don't have a way to accurately guess eye color since there are up to sixteen different genes that could be responsible for helping to determine eye color.
Though scientists used to believe that it was a relatively simple case of blue eyes being a recessive gene, and brown eyes being a dominant gene, it's now been found that eye color is determined by as many as 16 different genes. In fact, almost any combinations of parent-child eye color can occur. In general, darker colors tend to dominate lighter colors.
That said, we do know that the main genes found to determine eye color are OCA2 and HERC2. There is a fun tool that you can use to try to guess your future baby's eye color based on your eyes, your siblings' eyes, and your parents eyes.
Here's the eye-color calculator if you want to give it a try!
Other Color Variations
There are other variations that can occur in eye color aside from basic color. As you've learned, the iris is a complicated place! Its color comes from the combined effect of texture, pigmentation, fibrous tissue and blood vessels within the iris and stroma. Here are some other eye variations that can occur.
This is where one eye is differently colored from another one, or one iris has different colors in it. Kate Bosworth is a good example of this. This results from uneven melanin content.
A limbal ring is a dark ring around the iris of an eye. Since they fade with age, they usually signify youth and are considered attractive.
Eye Color Is Not Black and White
If you look at your friends’ eyes, you might find it hard to figure out exactly what color they are. Many eyes look like they have different colors toward the middle versus towards the edge, or have small variations around the iris.
This is especially true for people with lighter colored eyes. You might also notice flecks of color in them. Each of this is part of what makes each eye extremely unique. Irises (like fingerprints) are highly unique. Even genetically identical people, like twins, have different iris textures.
The more you look at eyes, the more you'll notice how unique each and every one is. So just remember that your eyes are special, no matter what color they are!
From The Tech Museum of Innovation:
From Ask a Mathematician:
So, what is the rarest eye color in humans?
Unfortunately, there is no eye color that has been fully agreed upon as the rarest, though green-eyed and amber-eyed people are both extremely rare. In fact, the rarest eye color is different in different geographical locations. In some parts of the world, green eyes are rarer than amber eyes or vice versa.
Most people consider green to be the rarest eye color in the world, though many others consider amber to be even more unusual. Therefore, it’s safe to say that either green or amber is the rarest color in the world.
However, If you look at the eye as a whole and not only the color given off by the iris, then violet eye color with little dispute is probably even rarer than green or amber eye colors.