The Rarest Eye Colors in the World (and Percentages of the Population That Has Each)

1. Gray
Less than 1% of the world population has gray eyes. Different ethnic groups and geographical areas influence the variations of it. How this color occurs is not entirely understood. Lighting plays a role in how intense this color appears. Sometimes those with gray eyes have a bluish-gray or smokey gray tint in their irises. These eyes are more common in people from northern and eastern Europe.   
2. Green
Green eyes exist in around 2% of the global population. These are more common in some European countries such as Iceland and Ireland. The chance of having green eyes decreases in people with other ethnic backgrounds. Though it is rare, it still happens. The green color comes from a lack of melanin in the iris, allowing light to display and create the appearance of green.
3. Hazel
10% of the world’s population has hazel eyes, and experts believe it comes from a combination of orange, green, and gold. Sometimes hazel eyes have kind of an amber color, so hazel and amber are often grouped together. People that have these eyes mostly come from places like Brazil. Those with Spanish heritage and those from the middle east are more likely to inherit this eye color. There are several hazel variations. For example, there is gray hazel, blue hazel, brown hazel, green hazel, golden hazel, and even multicolored hazel which is just as mesmerizing as it sounds!
4. Blue
Blue eyes are less common compared with other eye colors; the world population of those with blue eyes is about 8 – 10%. An important genetic factor to remember is that in order for the offspring to have blue eyes, both parents have to have the genes. Countries with the most blue-eyed people include Denmark, Estonia, and Sweden. Like with hazel eyes, there is a variation of blue as well. There is pale blue (also known as sky blue), and the variations continue to shades that are a bit more concentrated such as gray-blue or even intense turquoise. Again, the surrounding light aids the variation, making blue eyes appear darker or lighter.
5. Brown
Brown eyes are the most common throughout the world. People that have these colored eyes make up about between 55 to 79% of the population. The higher the levels of melanin, the darker brown eyes the offspring inherits. Lower levels of melanin result in lighter eyes being passed down to the offspring. This color is considered a dominant trait, which means that if only one parent has brown eyes, that variation is sufficient to pass it on. People with brown eyes are mostly African, Asian, Native American, and have Hispanic heritage. Link: a-z-animals.com