Eyes come in a variety of colors, from the common browns and blues to the less frequent greens, hazels, grays and violets. But how rare are hazel eyes compared to green eyes? Let’s take a closer look at the occurrence of these eye colors worldwide.
What are Hazel Eyes?
Hazel eyes are multicolored eyes that consist of shades of brown, green and gold. The amount of each color present can vary greatly from person to person, which is why hazel eyes can range from light golden-brown to a darker forest green. Unlike single-colored eyes, the appearance of hazel eyes can also shift slightly day to day based on lighting conditions, clothing colors and makeup.
The main feature that defines hazel eyes is the presence of melanin, the pigment that also determines hair and skin color, in the front iris layer. Higher amounts of melanin lead to eyes that appear darker brown or green, while lower amounts result in eyes that skew toward amber and gold tones.
What are Green Eyes?
Green eyes contain low to moderate amounts of melanin and feature specks of yellow and orange pigments. The yellow-orange pheomelanin produces brighter flecks of gold in the iris, which reflects light and makes green eyes stand out. Pure green eyes with little to no brown or gold are among the rarest eye colors in humans.
The green eye color is established by the blend of pigments and the density of cells containing melanin within the iris. Higher density with moderate melanin produces a darker green hue, while moderate density and low melanin appears light green or sage green. Very low density with little melanin results in a blue/green iris color.
Hazel Eyes vs Green Eyes
Although hazel and green eyes may look similar to some, there are key differences between the two:
- Hazel eyes have a yellow/brownish melanin pigment while green eyes have primarily a blue/gray melanin pigment.
- Hazel eyes appear to shift in color and often contain multicolored specks. Green eyes are more solid in hue with fewer color variations.
- Hazel eyes are defined by their combination of brown, amber, gold and/or green. Green eyes mainly exhibit shades of gray, emerald, jade and sage green.
In essence, hazel eyes are multicolored while green eyes are a more solid green/blue color. However, hazel eyes that appear very green may be mistaken for true green by some. The only way to really distinguish the two is to closely examine the pattern and pigments of the iris.
Prevalence of Hazel vs Green Eyes Worldwide
Global estimates indicate that hazel eyes are rarer than pure green eyes worldwide. Here is a breakdown of the estimated occurrence of these eye colors:
| Eye Color | Global Population |
|---|---|
| Hazel Eyes | 5% |
| Green Eyes | 2% |
Hazel eyes are estimated to occur in around 5% of the global population, while true green eyes are found in only around 2% of people worldwide. However, prevalence varies significantly based on geographic region and ethnicity.
Hazel Eyes Prevalence
Hazel eyes are most common among the following ethnicities:
- Caucasians – Up to 10%
- Hispanics – 5 to 10%
- Asians – 5 to 10%
- Native Americans – 5 to 10%
- Middle Easterners – 2 to 10%
They are less common among those of African, South Asian and Aboriginal Australian descent, with rates under 2% each among these populations.
Region-wise, hazel eyes are most prevalent in countries with higher Caucasian populations, including:
- United States (10%)
- Canada (10%)
- Australia (10%)
- New Zealand (10%)
- Northern Europe (~10%)
They are also moderately common in parts of Central Asia, the Middle East, North Africa and Latin America at 5-10% occurrence.
Green Eyes Prevalence
In contrast, green eyes are most common in the following ethnic groups:
- Northern Europeans – up to 10%
- Celtic people – up to 10%
- Germanic people – up to 4%
- Slavic people – up to 3%
- Jewish people – up to 3%
True green eyes are very rare outside of Europe and countries settled by European migrants. The highest rates are seen in:
- Ireland (10-30%)
- Scotland (15-30%)
- Wales (9-15%)
- England (5-15%)
- Northern Germany (3-10%)
- Scandinavia (1-5%)
- Iceland (15-25%)
Overall, hazel eyes outnumber green eyes in most parts of the world except North and West Europe.
Genetics Behind Hazel and Green Eyes
Eye color is determined by variations in over a dozen genes that help produce melanin. Most of the main genes associated with hazel and green eyes are as follows:
Hazel Eye Genes
- OCA2 – Primarily controls brown/blue eye color. Certain variations allow for partial melanin expression which can produce hazel eyes.
- TYR – Influences brown/green and hazel eye color.
- SLC45A2 – Helps determine brown/amber eyes versus blue eyes.
- SLC24A4 – Associated with golden rings common in hazel eyes.
Green Eye Genes
- OCA2 – Mainly controls brown/blue eye color. Reduced activity leads to green hue.
- TYRP1 – Key contributor to green/brown eye variations.
- HERC2 – Regulates OCA2 activity and green/hazel eye color.
The exact combination and interaction of these genes produces the various shades of hazel and green eyes seen worldwide. But essentially, hazel eyes arise from moderate melanin production while very low melanin levels result in green eyes.
Are Hazel or Green Eyes Dominant?
Neither hazel nor green eyes are dominant over other eye colors. Theinheritance patterns are as follows:
- Hazel eyes – Generally recessive to brown but dominant over blue.
- Green eyes – Recessive to both brown and blue eyes.
This means:
- If one parent has hazel and the other brown eyes, the child will likely have brown eyes.
- If one parent has green and the other blue eyes, the child will probably have blue eyes.
However, because multiple genes influence eye color, variations can occur. The child may end up with hazel or green eyes if other gene variants are inherited from parents carrying recessive alleles.
Conclusion
In summary, hazel eyes are rarer globally than pure green eyes. Hazel eyes occur in around 5% of the world’s population compared to just 2% for green eyes. However, hazel eyes are more common than green eyes across most of the world except in northern Europe.
The prevalence of hazel and green eyes varies significantly by region and ethnicity based on assorted genetic factors. But overall, hazel eyes arise from moderate melanin levels while very low melanin produces green eyes. Neither trait is completely dominant over other eye colors, allowing room for diverse genetic expression.
So in the end, hazel eyes are more rare worldwide than green eyes. But both add beautiful and unique coloration to the diverse spectrum of human eye colors.
