Gray Eyes: Causes, Pros, and Cons

Gray eyes are both beautiful and relatively rare. The color is caused by the front layer of the iris having less melanin than the back layer.

Your gray eyes may change color depending on the ambient light, your clothing, or your makeup. Sometimes, your iris looks blue. Sometimes, it looks green.

How Does Someone Get Gray Eyes?

Your iris, the colorful ring around the pupil at the center of the eye, is responsible for the gray color. Your genetic makeup plays a role. 

Multiple genes interact to influence eye color. Even parents with the same eye color could have a child with completely different colored eyes, including gray. But the color does tend to appear more frequently in people with a similar genetic background. 

Shades of Gray

Gray eyes come in all sorts of colors, including smoke, dark gray, almost hazel, bluish-gray, and greenish-gray. 

This eye color is among the most variable. The color may seem to change depending on your clothing, surrounding lighting, weather, or medications taken. 

The Gray Color Explained 

People with gray eyes have less melanin at the front of the iris, but the back is brown with melanin. Light enters the eye, interacts with the lack of light in the iris front, and is reflected.

The stroma between the two layers of the iris contains collagen that reflects light. The reflection causes a cloud in the stroma, which may manifest as gray, blue, or green.

Facts About Gray Eyes

• About 3% of the world’s population has gray eyes, making this the second most rare eye color. 
• Gray eyes are common in Central Asia, South Asia, and the Middle East. Additionally, the Algerian Shawia people often have gray eyes. 
• Gray eyes have less melanin in the front of their iris.

Health & Gray Eyes

While medications can change eye color in almost everyone, people with gray or light-colored eyes are particularly susceptible. In a study of a prostaglandin eye drop, about two-thirds of people with light-colored eyes noticed a shift in hue. 

Lighter colored eyes can come with health risks. For example, researchers have known for decades that melanoma rates are higher in people with light eyes versus those with brown eyes. The melanin within a brown eye might offer protection that gray eyes just don’t have. 

While you might want to pass your pretty gray eyes to your children, it’s not always easy. Genetic testing of eye color reveals that there are multiple hue variations among humans, and they’re not always easy to predict via genetics. 

Risks Associated With Gray Eyes 

While gray eyes can be beautiful, they also come with a few drawbacks and risks. Knowing what they are can help you protect your health. 

Light Sensitivity 

Melanin pigment in the eye reduces light sensitivity. People with light-colored eyes cannot withstand harsh lighting. They squint, lose focus, and may even experience pain when exposed to bright light, a condition called photophobia.

The discomfort is temporary. You can mitigate it by avoiding bright light if you have gray eyes. It does not cause loss of vision, even in the long term.

Ocular Melanoma 

Ocular melanoma is an eye cancer that affects the eye’s uvea. You will get cancer after exposure to UV rays, and people with light eyes are more prone than those with darker eyes. It is rare and has an annual 0.0006% chance of occurrence.

People with lighter eyes should take precautionary measures like wearing wide-brimmed hats and polarized sunglasses to minimize UV exposure. Melanoma can result in loss of vision or the spreading of cancer cells.

Skin Cancer

In most situations, gray eyes are accompanied by fair skin. Melanin pigment offers protection from the sun’s UV rays. 

Fair skin can redden, get freckles and sunburns easily, and is prone to skin cancer. This does not mean that people with a dark complexion cannot get skin cancer. 

Benefits of Gray Eyes 

The rarity of gray eyes can make them attractive or even appealing. You may never know what your eyes will look like, and they could change throughout the day. 
Your eyes may also be stronger. Gray-eyed people have more collagen than usual in the cornea’s stroma. Usually, collagen strengthens the cornea while boosting the curvature, especially where the corneal layers are thin. This fortification maintains the shape of the eye. 

References

1. Your Blue Eyes Aren’t Really Blue. (June 2023). American Academy of Ophthalmology.

2. The World’s Population by Eye Color. World Atlas.

3. The Chaouis of Algeria. Algeria.com.

4. The Incidence and Time-Course of Latanoprost-Induced Iridial Pigmentation as a Function of Eye Color. (February 1997). Survey of Ophthalmology.

5. Risk Factors for Ocular Melanoma: Western Canada Melanoma Study. (April 1985). Journal of the National Cancer Institute.

6. Digital Quantification of Human Eye Color Highlights Genetic Association of Three New Loci. (May 2010). PLOS Genetics.

7. Specific Eye Conditions, Corresponding Impact on Vision, And Related Educational Considerations. (February 2016). Texas School for the Blind and Visually Impaired.

8. Ocular melanoma. (2018). National Organization of Rare Disorders.

9. Skin Color Adaptation. Palomar College.

10. Eye Color and Its Inheritance. Cornell University.