Eyes can be many colors, and everyone’s eye color is unique. But grey eyes are among the rarest in the world. Most people’s eyes fall into one of these main eye color categories:
- Amber
- Blue
- Brown
- Grey
- Green
- Hazel
Although grey eyes are more common than colors like pink or red, which are extremely rare, they are less common than blue, brown, or hazel eyes. Read on to learn how many people have grey eyes and what causes this eye color.
What Percentage of People Have Grey Eyes?
It’s estimated that only 3% of the world’s population has this eye color, and no two people with grey eyes have the exact same color.
Grey eyes can look grey-blue, grey-green, dark grey, or almost hazel. They can also seem to change color depending on the color of clothing a person is wearing or the lighting in their environment.
What Causes Eyes to Turn Grey?
Genetics, melanin, and collagen are responsible for your eye color.
Genetics
Scientists used to believe that children inherited only one eye color gene from their parents. But they now know that multiple genes are involved in the process. That’s why parents with brown eyes can have a child with grey or other eye colors.
Melanin
Melanin is a pigment in the body that dictates eye, skin, and hair color. Kids inherit genes from their parents that determine how much melanin they will have.
Melanin is in the iris, which is the colored part of the eye surrounding the pupil. The iris has two layers of tissue, one in front and the other in back. Eye color is determined by the type, amount, and distribution of melanin in the iris layers.
In most eye colors, the back layer of the iris has a significant amount of melanin.
In grey and other light-colored eyes, the front layer of the iris has little to no melanin. In brown eyes, it has a higher amount. The amount of melanin in the front layer of your iris is what helps give your eyes their color.
No one knows for sure exactly why some people have grey eyes. But it’s generally believed they are the result of a genetic mutation.
Collagen in Eyes
Collagen is a protein in the body that gives your tissues strength and structure. It’s present in many parts of your body including your skin, bones, muscles, blood vessels, and eyes.
Collagen is responsible for giving your eyes structure. It supports the cornea (the clear, outermost layer of the eye) and the sclera (the white of the eye), but it’s also present in the front layer of the iris.
Grey eyes often have more collagen in them. When light reflects off the collagen in the iris, it causes the irisit to look cloudy and gives it a greyish color.
Grey Eyes and Your Health
People with grey eyes may have an increased risk of experiencing certain health issues, including:
- Light sensitivity – Melanin helps protect the eyes by absorbing light. Since grey eyes have less melanin, they can be more sensitive to bright light.
- Increased cancer risk – The melanin in your eyes also helps protect you from the sun’s harmful ultraviolet rays. With less melanin, grey eyes are more susceptible to a very rare eye cancer called optical melanoma.
There are may also be benefits to having grey eyes. People with this eye color are less likely to experience:
- Vitiligo (a skin disorder and autoimmune disease)
- Sensitivity to certain medications
Those with grey and other light-colored eyes also tend to have less pain and anxiety when giving birth.
Can Your Eyes Change Color?
At times, your eyes may appear to change color, such as in certain lighting or when you wear certain color clothing. This is usually due to an optical illusion rather than a change in your iris color.
It’s quite rare for your actual eye color to change beyond childhood. However, certain health conditions, medications, and other factors can affect the color of your eyes. Changes in your pupils (such as when they become wider or smaller) can also impact the color of your irises.
Some eye conditions, such as cataracts, can cause the appearance of your eye color to change. A cataract is when your eye’s natural lens becomes clouded or hazy, giving your eyes a white or bluish tint.
Other health conditions may also affect your eye color. If you’ve noticed your eyes have changed color, get an eye exam as soon as possible.
A grey spot on your sclera (the white of your eye) can be caused by a number of factors, such as:
- Congenital eye conditions
- Eye infections
- Eye dryness
- Eye injuries
- Silver accumulation in the eyes
While these grey areas could be harmless, they might also point to a more serious condition. See your eye doctor right away if you notice grey spots on your eyes so they can be diagnosed and treated as needed.
What Color Glasses Look Best With Grey Eyes?
You can show off your unique eye color with the right color frame. Grey, silver, and light blue can make your eyes pop. Here are a few of our favorites:
