Hazel eyes are often described as a mix between light brown and green. They have a multicolored appearance that can range from light brown to dark golden or greenish brown. Many people consider hazel eyes to be quite unique and attractive.
But just how rare are hazel eyes? Here’s a closer look at the prevalence and causes of this eye color.
How common are hazel eyes?
Hazel eyes are relatively uncommon globally. Recent surveys and studies estimate that they occur in around 5–10% of the world’s population. However, hazel eyes are more common in certain ethnicities and geographical regions.
Here is a breakdown of hazel eye color prevalence by region and ethnicity:
| Region/Ethnicity | Prevalence of Hazel Eyes |
|---|---|
| Caucasians | 5-10% |
| Hispanics | 10-15% |
| Northern Africa | 5-10% |
| Central Asia | 20-30% |
| North America | 5-10% |
As shown above, hazel eyes are most prevalent among people of Hispanic, North African, and Central Asian descent. They occur in about 5-10% of Caucasians and North Americans.
Overall, hazel is considered to be one of the rarer eye colors globally. But in certain ethnic groups they are relatively common.
What causes hazel eyes?
Hazel eyes are caused by a combination of Rayleigh scattering and a low to moderate amount of melanin in the iris.
Rayleigh scattering refers to the scattering of light by particles that are smaller than the wavelengths of visible light. This scattering reflects lighter shades from the amber and green portions of the light spectrum, contributing to the multicolored appearance of hazel eyes.
Melanin is the pigment that also determines brown and blue eye colors. Hazel eyes have a small to moderate amount of melanin concentrated toward the outer border of the iris. This gives hazel eyes their characteristic color pattern.
The exact hue of hazel eyes is determined by the specific combination of Rayleigh scattering and melanin levels. This is what creates the wide range of shades seen in hazel eyes – from golden-brown to green-brown.
What are the different shades of hazel eyes?
There are many possible shades that hazel eyes can present:
- Golden hazel – Ranging from rich gold to light amber with little green.
- Green hazel – Varying mixtures of green and light brown.
- Brown hazel – Golden-brown to dark brown with minimal green.
- Grey hazel – Very light brown with specks of grey and green.
- Multi-colored hazel – Distinct shifts between green, gold, and brown.
The most common hazel shades are golden-brown and green-brown. But there can be significant variation in coloring and patterns.
What causes the different shades of hazel eyes?
The specific shade of hazel eyes depends on two factors:
- Concentration of melanin pigment
- Amount of Rayleigh scattering
Higher melanin concentrations create darker brown/golden hazel shades. Lower levels result in lighter green-brown shades. Rayleigh scattering reflects amber and green light, influencing the hue as well.
The combination and concentration of these two elements produces the full spectrum of hazel shades, from rich amber to deep emerald green.
Do hazel eyes change color?
Hazel eyes often appear to shift in color and pattern. But the eye itself does not actually change color after infancy. Here’s why hazel eyes can seem to change:
- Lighting conditions – Hazel eyes reflect different shades in different lighting. Golden hues emerge in sunlight while brown comes out more in shade.
- Blood vessels – Expanded or contracted blood vessels around the iris can impact color.
- Age – Melanin and Rayleigh scattering patterns can shift slightly over time.
- Mood – The size of the pupil also alters the shade and pattern visible.
While hazel eyes may appear multi-colored due to these factors, the fixed concentration of melanin and structural composition remain unchanged.
Do hazel eyes run in families?
Hazel eye color does have a genetic factor. However, the inheritance patterns are complex due to multiple genes being involved. Some patterns include:
- A child can inherit hazel from a parent with either green/brown eyes or hazel eyes themselves.
- Two blue eyed parents can have a hazel eyed child due to recessive genes.
- If one parent has hazel eyes, there is a 50/50 chance a child will as well.
Overall, hazel eyes do commonly run in families. But the exact hue or pattern cannot be predicted solely based on the parents’ eye colors.
Are hazel eyes connected to any health conditions?
Hazel eyes are not directly associated with any health conditions or issues. However, some eye disorders can sometimes impact hazel eyes more noticeably. These include:
- Cataracts – Clouding in the lens can diminish Rayleigh scattering, shifting hazel eyes toward brown.
- Wilson’s Disease – Copper buildup in the iris can discolor hazel eyes greenish-brown.
- Horner’s Syndrome – Nerve damage leads to uneven pupil size, enhancing multi-colored look.
But these disorders are not specific to hazel eyes and can impact any iris. Overall, hazel eye color itself does not increase health risks.
Conclusion
In summary, hazel eyes are uncommon globally but more prevalent in certain ethnicities. Their unique multicolored appearance stems from Rayleigh scattering and moderate melanin levels. The specific hazel hue depends on the interaction between these two factors.
While hazel eyes may seem to shift in shade, the eye color itself is fixed after infancy. Changes in lighting, blood flow, and age can create an illusion of color change. And although family history influences the likelihood of hazel eyes, their inheritance patterns are complex.
Hazel eyes are widely considered to be quite beautiful and unique. So if you have them, appreciate your rare eye color!