You already know that human eyes come in different colors including amber, hazel, green, and blue. However, gray is the rarest among all of them and it has been reported to be the loveliest as well.
This makes the eye color extremely fascinating so you may find yourself wanting to know more about it. But, just how uncommon is gray eye color?
The Rarity of Gray Eyes
Gray eye is a trait that is exhibited only by 3% of the world’s population. Now you may want to note that the intensity and hue of gray eyes may vary from individual to individual with some having gray-blue, gray-green, or just dark gray eyes.
This eye color is prevalent in Eastern and Northern Europe.
What does Having Gray Eyes Mean?
When you hear of eye color, it essentially refers to the iris color. The iris is the ring of tissue surrounding the pupil. The iris color is highly dependent on the presence of melanin the same pigment that determines both hair and skin color.
That then means that eyes with more melanin appear darker than those with less of the pigment.
What does Research Say?
The authoritative Medical News Today quotes a 2020 article by World Atlas that states gray-eyed people make up 3% of the global population.
Unfortunately, no peer-reviewed studies are available backing up this claim but if it were true, then about 237 million individuals across the globe have gray eyes. However, the number may be lower in the US considering that the eye color is common in parts of Northern Africa and Europe.
Another source, the authoritative HealthLine claims that less than 1% of the world’s population has gray eyes, and if this is the case, then it translates to about 79 million people globally.
Again, the figure may be (proportionately) lower in the US because gray eye color is prevalent in Europe and Northern Africa.
Often, gray-eyed persons are counted along with those with blue eyes. According to statistics appearing on PubMed, blue-eyed persons make up 8-10% of the world population. The percentage of gray-eyed people in that group is not as clear but just from that, you can see just how uncommon gray eyes are.
Are Gray Eyes Dominant or Recessive?
You see, traits like eye color are genetic and what that means is that they can be caused by dominant or recessive genes. Gray eyes are neither dominant nor recessive.
In the past, scientists thought that eye color was caused by a dominant gene and that lighter eyes like gray were caused by recessive genes while darker eyes like brown were caused by dominant genes.
The scientists concluded that recessive genes only carried the day when two copies of it were present so if a baby inherited one gene for brown eyes from one parent and one for gray eyes from the other parent, the gene for brown eyes would take over hence the baby would have brown eyes.
However, scientists today have realized that this is not true and that numerous genes contribute to the eye color of an individual.
What are the Variations of Gray Eyes?
As mentioned earlier, gray eyes come in different shades. These are dark gray, gray-blue, and gray-green. Gray-eyed people may notice that their eyes tend to change color based on eye makeup or the color of clothing they wear.
Even the brightness of light surrounding them and the emotions they feel can also affect the color intensity. The same applies when using medications like opioids that cause enlarging of the pupils.
Quick Facts about Gray Eyes
Here are some facts that may interest you about gray eyes.
*They are more light sensitive and that is because melanin protects the eyes when it absorbs light. Since people with gray eyes have less of the pigment, they have less protection. This then means that their eyes are more sensitive to light.
*Another thing about gray eyes is that they are more susceptible to eye cancer. Again, this has to do with melanin levels. Since people with this eye color have less of the melanin pigment, they are less protected from the sun’s UV rays that are known to cause cancer.
*One of the best things about having gray eyes is that you are less likely to develop skin conditions like vitiligo. That is because you are less likely to suffer from the autoimmune diseases that lead to the condition.
How do Gray Eyes Compare to Brown Eyes
Now that you know what you need to about the rarest eye color, you probably want to know how it compares to the most common eye color, which is brown.
Brown-eyed people make up about 79% of the world’s population, which is a huge number, compared to the mere 3% that make up gray-colored people.
You may also want to note that brown eyes are considered the original eye color and they are dominant in Asia and Africa to this day. On the other hand, gray eyes are extremely rare and are usually common in Europe and parts of Northern Africa.
Undoubtedly, gray eyes are extremely rare. Only a fraction of the world’s population has this trait and that makes them exotic.