10 Fun Scientific Facts About Blue Eyes
Apr 25, 2025
Anna
Blue eyes are the most desired eye color. Blue eyes are truly unique, and their beautiful, eye-catching color often catches our attention. But have you ever wondered what makes them so special? Aside from their attractive appearance, blue eyes have some fascinating secrets related to science, genetics and even history. For example, did you know that all blue-eyed people share a common ancestor? Or that the color of blue eyes is actually the result of light hitting the iris? In this article, we'll cover 10 interesting facts about blue eyes that will give you a whole new perspective on blue eyes!
What determines eye color?
Eye color is mainly determined by a few key genes, with the OCA2 gene being the most important. Another gene, called HERC2, also plays a big part in deciding your eye color. These genes work together to control the amount of pigment, called melanin, in your eyes. The more melanin you have, the darker your eyes will be. Less melanin means your eyes will be lighter, like blue. Melanin also affects your hair and skin color – the more melanin you have in your hair or skin, the darker they look. So, if you have both blue eyes and red hair, you're lucky enough to have one of the rarest combinations in the world!
Are all blue-eyed people related?
Yes, it turns out that all blue-eyed people share a common ancestor! Researchers found that a single genetic mutation, which happened between 6,000 and 10,000 years ago, is the reason why people have blue eyes today. This mutation happened in one person, and it spread through generations. The mutation is on the OCA2 gene, which controls melanin production in the eyes. This change actually reduces the amount of melanin, making eyes lighter in color. Before this mutation, all humans had brown eyes, since brown is the natural color of melanin.
10 facts about blue eyes
1. Blue is not the rarest eye color
Quite a surprise, isn't it! Blue eyes aren't the rarest eye color! In fact, they are the second most common eye color in the United States, right after brown eyes. About 27% of Americans have blue eyes, while 45% have brown eyes. Around the world, about 8 to 10% of people have blue eyes, but brown eyes are still the most common, with 70 to 80% of people having them. The rarest eye colors are green and gray. Even rarer is heterochromia, where a person has two different colored eyes!
2. Your blue eyes aren’t actually blue
Believe it or not, your blue eyes aren’t actually blue! The color you see isn’t from a blue pigment. Instead, it’s all about how light interacts with your eyes. Blue eyes have less melanin, which means they absorb less light. The light that does enter is scattered by collagen fibers in the eye, and this scattering makes the eyes appear blue. On the other hand, people with darker eyes have more melanin, which helps them absorb more light.
3. Blue-eyed people may drink more alcohol
It turns out that blue-eyed people might drink more alcohol! Research published in the American Journal of Medical Genetics found that people with blue eyes have an 83% higher risk of becoming alcohol dependent compared to those with brown eyes. The study also discovered that certain genes related to eye color may interact with genes that influence alcohol dependence.
4. Blue-eyed males may have female-shaped faces
It seems that blue-eyed males may have faces that look more feminine! Research by anthropologist Peter Frost shows that blue eyes are often linked to features usually seen in female faces, like smaller and sharper chins, narrower mouths, smaller noses, and wide-set eyes. On the other hand, brown eyes are connected with more masculine features, like broader chins, larger noses, and closer-set eyes. Frost suggests that this might be because blue eyes and more feminine features can develop when a male fetus has higher levels of estrogen during development. However, this doesn’t apply to females, as their bodies typically have enough estrogen to develop more feminine traits naturally.
5. Blue-eyed people are more sensitive to light
People with blue, green, or gray eyes tend to be more sensitive to light, a condition called "photophobia." This is because they have less pigmentation in their eyes, which means they have less protection against bright light, like sunlight or even fluorescent lights. However, it’s a good idea for everyone, no matter their eye, skin, or hair color, to protect their eyes and avoid too much sun, especially during the middle of the day.
6. Blue-eyed people may feel less pain
Here's a surprising benefit of having blue eyes: research suggests that people with lighter-colored eyes, like blue or green, may have a higher tolerance for pain than those with darker eyes. In a study published in the Journal of Pain, women in labor with brown or hazel eyes experienced more anxiety, trouble sleeping, and pain compared to those with lighter eyes. Of course, how we feel pain is also influenced by other factors, like age, gender, and hair color.
7. Blue-eyed people have a higher risk of melanoma
People with blue eyes have a higher risk of developing melanoma, a type of skin cancer, especially if they also have fair skin and light hair. But even if you don’t have red hair or pale skin, having blue eyes alone can increase your risk. This is because blue-eyed people have less melanin, which is the pigment that helps protect against ultraviolet (UV) light. In addition, blue-eyed individuals are also more likely to develop uveal melanoma, a rare type of cancer that affects the eye.
8. Blue-eyed people may be more competitive
If you’re looking for someone to push you in a challenge, whether it’s athletic or academic, a friend with blue eyes might be just the person! Research has found that people with lighter eyes, like blue, tend to be less agreeable, meaning they’re often more competitive. The study, published in Current Psychology, suggests that lighter-eyed people, including those with blue eyes, are usually more self-centered and skeptical. On the other hand, people with darker eyes are often seen as more caring and generous.
9. Blue Eyes at Birth Doesn’t Mean Blue Eyes For Life
Although blue eyes are rare in adults, they’re actually quite common at birth. Most babies, especially Caucasian ones, are born with blue eyes because their eyes don’t have their full amount of pigment yet. As they grow, their bodies produce more melanin, which can cause their eye color to change during early childhood. So, just because a baby has blue eyes doesn’t mean they’ll always have them!
10. You can’t predict if a child will have blue eyes
It used to be thought that you could easily predict a child’s eye color, including if they’d have blue eyes, based on their parents’ eye colors. However, geneticists now know that eye color is influenced by up to 16 different genes, not just one or two as previously believed. On top of that, the structure of the iris itself can also play a role. So, even if both parents have blue eyes, there's no guarantee their child will have blue eyes too. It’s just too complicated to predict for sure!
How can I get blue eyes?
Blue eyes are the most desired eye color. If you want blue eyes, consider wearing blue contacts from ICOICE. These contacts can easily change the color of your eyes, giving you an instant stunning blue eye effect. Whether you're going for an everyday look or a special occasion, blue contacts can add a unique splash of color to your eyes.
ICOICE Meta Blue|1 Year
ICOICE Meta Blue colored contact lenses have a stunning light baby blue hue with a delicate pattern that closely resembles the human iris. Whether your eyes are light or dark, these lenses deliver a bright, natural look. This is undoubtedly our brand's best-selling shade.
ICOICE Sin Blue | 1 Year
ICOICE Sin Blue lenses feature a stunning navy blue tone with a delicate gray radial texture blooming around the pupil. The lenses take on a frosted light blue hue, effectively changing the color of your eyes. Suitable for light and dark eyes!
ICOICE Bloom Blue | 1 Year
ICOICE Bloom Blue lenses have an attractive sky blue hue with a radial pattern that mimics the shape of a blue iris to naturally change the color of your eyes. These lenses are richly pigmented and are suitable for both light and dark eyes.
Blue eyes are the most desired eye color. Blue eyes are truly unique, and their beautiful, eye-catching color often catches our attention. But have you ever wondered what makes them so special? Aside from their attractive appearance, blue eyes have some fascinating secrets related to science, genetics and even history. For example, did you know that all blue-eyed people share a common ancestor? Or that the color of blue eyes is actually the result of light hitting the iris? In this article, we'll cover 10 interesting facts about blue eyes that will give you a whole new perspective on blue eyes!
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What determines eye color?
Eye color is mainly determined by a few key genes, with the OCA2 gene being the most important. Another gene, called HERC2, also plays a big part in deciding your eye color. These genes work together to control the amount of pigment, called melanin, in your eyes. The more melanin you have, the darker your eyes will be. Less melanin means your eyes will be lighter, like blue. Melanin also affects your hair and skin color – the more melanin you have in your hair or skin, the darker they look. So, if you have both blue eyes and red hair, you're lucky enough to have one of the rarest combinations in the world!
Are all blue-eyed people related?
Yes, it turns out that all blue-eyed people share a common ancestor! Researchers found that a single genetic mutation, which happened between 6,000 and 10,000 years ago, is the reason why people have blue eyes today. This mutation happened in one person, and it spread through generations. The mutation is on the OCA2 gene, which controls melanin production in the eyes. This change actually reduces the amount of melanin, making eyes lighter in color. Before this mutation, all humans had brown eyes, since brown is the natural color of melanin.
10 facts about blue eyes
1. Blue is not the rarest eye color
Quite a surprise, isn't it! Blue eyes aren't the rarest eye color! In fact, they are the second most common eye color in the United States, right after brown eyes. About 27% of Americans have blue eyes, while 45% have brown eyes. Around the world, about 8 to 10% of people have blue eyes, but brown eyes are still the most common, with 70 to 80% of people having them. The rarest eye colors are green and gray. Even rarer is heterochromia, where a person has two different colored eyes!
2. Your blue eyes aren’t actually blue
Believe it or not, your blue eyes aren’t actually blue! The color you see isn’t from a blue pigment. Instead, it’s all about how light interacts with your eyes. Blue eyes have less melanin, which means they absorb less light. The light that does enter is scattered by collagen fibers in the eye, and this scattering makes the eyes appear blue. On the other hand, people with darker eyes have more melanin, which helps them absorb more light.
3. Blue-eyed people may drink more alcohol
It turns out that blue-eyed people might drink more alcohol! Research published in the American Journal of Medical Genetics found that people with blue eyes have an 83% higher risk of becoming alcohol dependent compared to those with brown eyes. The study also discovered that certain genes related to eye color may interact with genes that influence alcohol dependence.
4. Blue-eyed males may have female-shaped faces
It seems that blue-eyed males may have faces that look more feminine! Research by anthropologist Peter Frost shows that blue eyes are often linked to features usually seen in female faces, like smaller and sharper chins, narrower mouths, smaller noses, and wide-set eyes. On the other hand, brown eyes are connected with more masculine features, like broader chins, larger noses, and closer-set eyes. Frost suggests that this might be because blue eyes and more feminine features can develop when a male fetus has higher levels of estrogen during development. However, this doesn’t apply to females, as their bodies typically have enough estrogen to develop more feminine traits naturally.
5. Blue-eyed people are more sensitive to light
People with blue, green, or gray eyes tend to be more sensitive to light, a condition called "photophobia." This is because they have less pigmentation in their eyes, which means they have less protection against bright light, like sunlight or even fluorescent lights. However, it’s a good idea for everyone, no matter their eye, skin, or hair color, to protect their eyes and avoid too much sun, especially during the middle of the day.
6. Blue-eyed people may feel less pain
Here's a surprising benefit of having blue eyes: research suggests that people with lighter-colored eyes, like blue or green, may have a higher tolerance for pain than those with darker eyes. In a study published in the Journal of Pain, women in labor with brown or hazel eyes experienced more anxiety, trouble sleeping, and pain compared to those with lighter eyes. Of course, how we feel pain is also influenced by other factors, like age, gender, and hair color.
7. Blue-eyed people have a higher risk of melanoma
People with blue eyes have a higher risk of developing melanoma, a type of skin cancer, especially if they also have fair skin and light hair. But even if you don’t have red hair or pale skin, having blue eyes alone can increase your risk. This is because blue-eyed people have less melanin, which is the pigment that helps protect against ultraviolet (UV) light. In addition, blue-eyed individuals are also more likely to develop uveal melanoma, a rare type of cancer that affects the eye.
8. Blue-eyed people may be more competitive
If you’re looking for someone to push you in a challenge, whether it’s athletic or academic, a friend with blue eyes might be just the person! Research has found that people with lighter eyes, like blue, tend to be less agreeable, meaning they’re often more competitive. The study, published in Current Psychology, suggests that lighter-eyed people, including those with blue eyes, are usually more self-centered and skeptical. On the other hand, people with darker eyes are often seen as more caring and generous.
9. Blue Eyes at Birth Doesn’t Mean Blue Eyes For Life
Although blue eyes are rare in adults, they’re actually quite common at birth. Most babies, especially Caucasian ones, are born with blue eyes because their eyes don’t have their full amount of pigment yet. As they grow, their bodies produce more melanin, which can cause their eye color to change during early childhood. So, just because a baby has blue eyes doesn’t mean they’ll always have them!
10. You can’t predict if a child will have blue eyes
It used to be thought that you could easily predict a child’s eye color, including if they’d have blue eyes, based on their parents’ eye colors. However, geneticists now know that eye color is influenced by up to 16 different genes, not just one or two as previously believed. On top of that, the structure of the iris itself can also play a role. So, even if both parents have blue eyes, there's no guarantee their child will have blue eyes too. It’s just too complicated to predict for sure!
How can I get blue eyes?
Blue eyes are the most desired eye color. If you want blue eyes, consider wearing blue contacts from ICOICE. These contacts can easily change the color of your eyes, giving you an instant stunning blue eye effect. Whether you're going for an everyday look or a special occasion, blue contacts can add a unique splash of color to your eyes.
ICOICE Meta Blue|1 Year
ICOICE Meta Blue colored contact lenses have a stunning light baby blue hue with a delicate pattern that closely resembles the human iris. Whether your eyes are light or dark, these lenses deliver a bright, natural look. This is undoubtedly our brand's best-selling shade.
ICOICE Sin Blue | 1 Year
ICOICE Sin Blue lenses feature a stunning navy blue tone with a delicate gray radial texture blooming around the pupil. The lenses take on a frosted light blue hue, effectively changing the color of your eyes. Suitable for light and dark eyes!
ICOICE Bloom Blue | 1 Year
ICOICE Bloom Blue lenses have an attractive sky blue hue with a radial pattern that mimics the shape of a blue iris to naturally change the color of your eyes. These lenses are richly pigmented and are suitable for both light and dark eyes.