What is the colored part of your eye?
Eye color refers to the color of your iris. The iris is the colored part of the eye that surrounds the pupil. Your pupil is the small black opening in the center.
The iris has two layers. Eye color results from the amount of pigment (melanin) in the front layer (stroma). Almost everyone (even people with blue or green eyes) has brown pigment in the back layer of the iris.
Your eye color is like your fingerprint. Nobody else in the world has the exact same eye color as you. The amount of melanin you have in your iris is completely unique to you.
How do eyes get their color?
Eye colors vary depending on how much melanin your body produces. Melanin is a naturally occurring pigment that gives color to the skin, hair and eyes.
Skin cells called melanocytes are responsible for producing melanin. Everyone's melanocytes produce different amounts of pigment. People whose skin cells don't produce much melanin have lighter eyes. People whose skin cells produce more melanin have darker eyes.
What determines eye color?
Scientists used to think that only one gene determines eye color. They thought that a simple pattern of inheritance caused someone to have more or less melanin. For example, they thought two blue-eyed parents could not have a brown-eyed child.
Scientists now know that the pattern of inheritance is more complex. Many genes work together to determine what eye color you have. Your eye color depends on the eye color of your parents and the eye color of your relatives. Sometimes genetic mutations (changes) cause someone to have different colored eyes than everyone else in their family.
What is the most common eye color?
About 10,000 years ago, everyone in the world had brown eyes. Scientists believe that the first blue-eyed person had a genetic mutation that caused the body to produce less melanin. Today, about half of the people in the United States have brown eyes.
Eye colors range from veryLight Blueto dark brown. Some eyes also have spots or patches of darker or lighter colors. Eye color can be of many different shades:
- Amber, which some people describe as copper, gold, or very light brown.
- Blue or gray, which occurs when someone has no pigment (melanin) in the front layer of the iris. About 1 in 4 people in the US has blue eyes.
- Brown, the most common eye color in the world.
- Green, the least common eye color. Only 9% of people in the United States have green eyes.
- Hazel, a combination of brown and green. Hazel eyes can also have flecks or flecks of green or brown. In the US, about 18% of people have hazel eyes.
How do blue eyes get their color?
People with blue eyes actually have no blue pigment. The iris looks blue only because of the light reflection.
An eye with less melanin absorbs less light. Collagen fibers in the eye scatter light and it reflects off the surrounding area, making the eyes appear blue. People with lighter eyes can be more sensitive to light because they have less pigment to protect their eyes from bright light.
What color eyes are babies usually born with?
Many babies are born with blue or brown eyes. But newborns can have any eye color. As a baby grows, melanin continues to develop. As a blue-eyed newborn develops more melanin in their iris, their eyes may darken or turn brown or hazel.
This change usually takes place during the baby's first year of life. But it can take up to a few years for the eyes to take on the color they will be for the rest of their lives.
Can eye color change over time?
Eye colors usually remain the same throughout a person's life. Certain health conditions and disorders can cause changes in eye color.
Her eye color seems to change a bit from time to time. For example, your eyes might look like they're a darker shade of blue if you're wearing a blue shirt. The color change occurs when light reflects off objects around you.
Some people have a ring of darker pigment around the outside of their iris. Vendors call this a limbic ring. It may fade and become less noticeable with age.
Can people have different colored eyes?
A condition called heterochromia causes the iris to be different colors. People with this condition may have different colors in one eye (for example, the iris may be half one color and half another color). Or they can be a different color in each eye.
In most cases, heterochromia results from a harmless gene mutation. It usually occurs sporadically, meaning there are no other symptoms or health issues. Rarely, heterochromia can result from an injury or disease, such as a B. a tumor in the eye. Called a conditionHorner Syndromecan also lead to heterochromia.
What Conditions Affect Eye Color?
Several conditions can affect eye color. These include:
- albinism:People with a hereditary disease calledalbinismhave little or no melanin in their eyes, hair and skin. People with albinism usually have very light blue eyes. They rarely have pink or red eyes. Without melanin, their iris is clear, revealing the blood vessels in the eye. The blood vessels give the eyes their pink or red color.
- Cataract:This condition causes the lens in the eye to become cloudy.Cataractcan make the eyes appear milky white or gray.
- Hornhautbogen (Senile Book):This condition, common in older people, causes a light gray or blue ring to appear around the cornea (a clear layer that stretches across the iris). Lipids (fatty substances) form the rings. Corneal arching can be a sign of thishigh cholesterol. Providers call this condition arcus juvenilis when it affects people under 40.
- Fuchs heterochrome Iridozyklitis:This condition usually occurs in only one eye and causes the iris to change color and the eye to lose pigment. It also causes inflammation in the eye. It can lead to cataracts and glaucoma.
- Pigmentdispersionssyndrom:This condition causes pigment to fall off the iris and get into other parts of the eye. In the areas with less pigment, the iris appears lighter.
- Uveitis:untreated,UveitisMay causebad sightand permanent blindness. The condition causes inflammation in the eye.
- Waardenburg syndrome:A rare genetic disorder, signs of Waardenburg syndrome include decreased pigmentation in the eyes, skin, and hair.
What drugs affect eye color?
A type of medication called prostaglandins can cause the iris to become discolored. Providers use prostaglandins for treatmentGlaucoma. Prostaglandin is also the main ingredient in a serum called Latisse® that lengthens lashes. These drugs can cause the eyes to darken.
Does Eye Color Affect Eye Health?
Providers have found a link between the color of your eyes and your risk of developing certain eye conditions. People with brown eyes are less likely to havemacular degeneration, eye cancerdiabetic retinopathy. Vendors believe this is because brown pigments offer more protection to the eyes and reduce the risk of these diseases. But people with brown eyes have a higher risk of gettingCataracts.
A note from the Cleveland Clinic
Your eye color is unique to you. No two people in the world have the same eye color. Eye colors range from light blue to dark brown and every shade in between. Some people have spots or streaks of different colors or a darker ring of pigment around the iris. Genes from your parents, grandparents, and other relatives determine what color your iris will be. These genes also play a role in the color of your hair and skin.