What Is the Rarest Eye Color?

Eye color is a distinct part of your appearance. It's included on a driver’s license and other forms of identification. It is also one of the primary descriptors used in a missing person’s report.

The iris is the pigmented part of your eye. Its color is determined by genes. Many basic level biology courses used to use eye color to break down how certain genes are passed on from parents to children. However, scientists now understand that eye color genetics is more complex, with multiple genes play a part in determining eye color.

The production of melanin in the iris is what influences eye color. More melanin produces a darker coloring, while less makes for lighter eyes. Green eyes are the rarest, but there exist anecdotal reports that gray eyes are even rarer.

Eye color isn’t just a superfluous part of your appearance. It can also say something about a person’s health.

close up of woman with brown eyes
 Getty Images / Colorblind Images LLC

Rare Eye Colors

Here are some of the rarest eye colors. 

Gray Eyes 

There’s not much information on gray colored eyes. However, a review of eye color classification shows that it is indeed considered a different eye color from blue.

People in Northern countries tend to have lighter colored eyes. In comparison, darker eyes are common in warmer locales for much the same reason people have darker skin in Southern countries.

In studies, gray and blue are often lumped together. The American Academy of Ophthalmology (AAO) explains that around 27% of people in the U.S. have blue eyes. They also include a category of other—which may include of gray eyes—that makes up 1% of the population.

Green Eyes

According to the AAO, green eyes are one of the rarest eye colors. Only 2% of the global population has green eyes.


People with heterochromia have two different colored eyes. Some people are born with it. It can happen at birth in conjunction with conditions such as piebaldism and Horner’s syndrome.

You can also develop heterochromia later in life. It can occur due to injury, medication, or illness. It’s rare for people to have heterochromia. In the U.S., fewer than 200,000 people have this condition.

It is possible for your eye color to change in adulthood. While lighting and environment may influence eye color perception, diseases, medications, and injury can also impact eye color later in life.

Brown freckles can develop in your iris over time, and while most are harmless, they can sometimes be cancerous. Some conditions, like Fuchs heterochromic iridocyclitis, can cause you to lose pigment in your iris, making the eyes appear lighter in color.


Several different genes play a part in determining your eye color. Most of them have something to do with the transport, production, and storage of melanin. Melanin is a pigment found in the skin, hair, and eyes. More melanin in the iris will produce brown eyes, while less of it may mean green, blue, or gray eyes.

While scientists—and probably your high school biology teacher—used to think that eye color inheritance was a simple matter of dominant and recessive genes, they now know that this isn’t the case.

Two people with brown eyes, for example, can indeed have a child with lighter eyes. Brown eyes are common, but there is no single dominant gene for brown eye color as was once believed.

Besides the amount of melanin produced, how much is present in the front of the iris and the back of the iris, as well as the composition of the stroma layer in between, determines eye color. Multiple genes are at work in determining these variables, and much about this is still not understood.

It’s possible to change your eye color using cosmetic contact lenses, but you need to be careful because improper use increases your chance of getting an infection. The AAO recommends seeing an eye care professional before using cosmetic contact lenses. You should also never buy contact lenses that don’t require a prescription.

The AAO also warns against surgery to change the color of your eyes. This kind of surgery can have serious side effects, including blindness and vision issues.

Eye Color and Health

Eye color may seem like something that just has to do with your appearance. However, some studies suggest that certain eye colors may increase a person’s risk of certain health conditions.

Research from 2011, for instance, suggests a link between blue eyes and type 1 diabetes. Similarly, a review from 2015 suggests a possible link between eye color and hearing loss. Evidence points to the possibility that people with darker eyes may have a reduced risk of non-age-related hearing loss.

A 2014 study presented at the American Pain Society meeting in 2014 concluded that women with light-colored eyes had a higher reported pain tolerance during pregnancy than those with darker eyes. However, it should be noted that the sample size for this study was relatively small, with a total of 58 women.

A similarly small-sized study of 60 subjects had the same finding when testing pressure pain thresholds and for pain related to cold. However, remember that correlation does not equal causation and more study is needed to prove these effects.

Frequently Asked Questions

  • How rare are grey eyes?

    Grey eyes are very rare, but it's difficult to know exactly what percentage of the population has them. People with grey eyes are often counted with people with blue eyes, which account for 27% of people in the U.S.

  • Is it possible to have natural red eyes?

    Yes, it is possible for a person to naturally have red eyes, but they're more of a light red or pink color instead of a bright red. This can happen to people who have albinism, a condition that causes less pigment to develop in a person's skin, eyes, and hair. If a person with albinism has clear irises due to a lack of melanin, blood vessels in their eyes become visible and result in the light red and pink appearance.

  • What causes eye color to change?

    Eye color change can be caused by genetics, disease, medication, and trauma. For example, some medications that treat glaucoma, a condition that causes increased eye pressure, can cause eye color to change over time.

  • How many people have hazel eyes?

    About 18% of the U.S. population has hazel eyes. This is due to light brown pigment in the iris interacting with blue light in the eye, which results in green, speckled, or hazel eyes.

Was this page helpful?
17 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Mukamal R. Why are brown eyes most common? American Academy of Ophthalmology.

  2. Grigore M, Avram A. Iris colour classification scales—then and nowRom J Ophthalmol. 2015;59(1):29-33.

  3. Katsara M-A, Nothnagel M. True colors: A literature review on the spatial distribution of eye and hair pigmentationForensic Science International: Genetics. 2019;39:109-118. doi:10.1016/j.fsigen.2019.01.001

  4. Gudgel DT. Your blue eyes aren’t really blue. American Academy of Ophthalmology.

  5. Boyd K. Eye color: unique as a fingerprint. American Academy of Ophthalmology.

  6. Turbert D. Heterochromia. American Academy of Ophthalmology.

  7. Rehman HU. HeterochromiaCMAJ. 2008;179(5):447-448. doi:10.1503%2Fcmaj.070497

  8. Why are my eyes changing color? American Academy of Ophthalmology.

  9. Southworth L. Eye color. Stanford at The Tech.

  10. Gudgel DT. Are costume contact lenses safe? American Academy of Ophthalmology.

  11. American Academy of Ophthalmology. Iris implant surgery to change eye color can be dangerous, american academy of ophthalmology warns.

  12. Stasio ED, Maggi D, Berardesca E, et al. Blue eyes as a risk factor for type 1 diabetesDiabetes/Metabolism Research and Reviews. 2011;27(6):609-613. doi:10.1002/dmrr.1214

  13. Mujica-Mota MA, Schermbrucker J, Daniel SJ. Eye color as a risk factor for acquired sensorineural hearing loss: a reviewHear Res. 2015;320:1-10. doi:10.1016/j.heares.2014.12.002

  14. Pietzak R. Can eye color predict pain tolerance? UPMC & Pitt Health Sciences News Blog.

  15. Holmgaard H, Hansen EØ, Dong NP, Dixen LB, Nielsen GA, Poulsen JN, Gazerani P. Individuals with dark eyes and hair exhibit higher pain sensitivity. Somatosens Mot Res. 2017 Mar;34(1):21-26. doi:10.1080/08990220.2016.1276439

  16. Boyd, K. American Academy of Ophthalmology. Eye color: Unique as a fingerprint.

  17. Rauch, K. American Academy of Ophthalmology. Why are my eyes changing color?

Additional Reading