This cancer is very rare, affecting six in every one million adults in the U.S. Individuals with gray eyes have less melanin and are at greater risk for an eye cancer called ocular melanoma. The more melanin your iris contains, the more protected you are from the sun’s damaging rays. Gray eyes increase the risk of certain eye cancers If this describes you, you can protect your eyes with UV-blocking polarized sunglasses and wide-brimmed hats on bright sunny days. People with light colored eyes (blue, green or gray) are more likely to be sensitive to bright light. When melanin pigment absorbs light, it helps protect the eyes. Scientists also think that the fibers in the stroma may scatter light in such a way that the iris appears gray. Dark gray eyes have a bit more melanin in that front layer than pale gray eyes. Gray eyes may contain just enough melanin in the front layer to dim the blue wavelengths of light that are reflected back by the tissue of the eye. Though scientists don’t yet know exactly what causes gray eye color, they believe that the genetics at work are likely the same as - or very similar to - the genetics behind the development of blue eyes. In lighter eyes, there is less melanin, and it is located in the back layer. Very little light is reflected back out, which is why the eyes appear brown or black.
Every iris contains two layers of tissue, one in front and one in back, joined by connective tissue in the middle called the stroma.ĭark eyes contain a lot of melanin in both the front and back layers of the iris. This brown pigment absorbs light, and the color of the eye depends in large part on how much melanin the eye contains. In all eyes, the amount of melanin in the iris regulates eye color. SEE RELATED: Eye anatomy: A closer look at the parts of the eye What causes gray eyes? This effect can also happen with certain medications, such as opioids, which enlarge the pupils. When that happens, gray eyes can appear darker - though of course the eyes aren’t actually a different color. People with gray eyes may also note that their eyes seem to change color depending on the color of clothing (or eye makeup) the individual is wearing, or how bright the surrounding lighting is.Įven mood can appear to change the tint of gray, because pupils dilate (open wider) when someone is experiencing extreme emotions, such as grief or joy. The intensity of gray eyes depends on the individual. Gray eyes can appear in various shades, including dark gray, gray-blue, gray-green or almost hazel. Most of those genes help regulate melanin. Today scientists know this is not the case and that many genes play a role in how eye color develops. It was thought that if you inherited one gene for brown eyes and one gene for blue eyes, the gene for brown eyes would dominate and both of your eyes would be brown. Scientists used to think that a person’s eye color was caused by one dominant gene, and that darker eyes (like brown eyes) were dominant while lighter eyes (blue eyes, green eyes, hazel eyes and gray eyes) were recessive.Ī recessive gene only shows up when there are two copies of it present. Gray eyes are neither recessive nor dominant. “Gray” is simply the preferred spelling in American English, while “grey” is the British English spelling used primarily in the U.K.Ĭlick to read the article and view the infographic NOTE: You may see it referred to as a “grey eye” rather than a “gray eye,” but it’s the same eye color. Eyes with a lot of melanin are darker, and eyes with less melanin are blue, green, hazel, amber or gray.
#Silver blue eyes skin
The color of the iris depends on the presence of a brown pigment called melanin, the same pigment that determines skin color and hair color. The pupil is an opening at the center of the iris that appears black, while the white part of your eye is called the sclera.
The color and intensity of gray eyes varies from person to person and can include dark gray, gray-green and gray-blue.Įye color actually refers to the color of the iris, a ring of tissue that surrounds the pupil.
Gray eye color is one of the loveliest and most uncommon, a trait shared by only 3% of the world’s population. Human eyes come in many colors - brown, blue, green, hazel, amber, and even violet or gray eyes.
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