Have you ever wondered why there are so many different shades of brown, blue, and green eyes?
Human eye color charts once were used to “predict” eye colors of children.
In the most simplified versions of these charts, brown eyes are considered dominant over both blue and green eyes. And green eyes are thought to be dominant over blue eyes.
While these concepts generally are true, the genetics of how eye colors are inherited turn out to be far more complicated than once thought.
You can’t simply determine the eye colors of grandparents and parents, then calculate the odds of what color a baby’s eyes will be. In fact, you can belong to a family with many generations of brown-eyed individuals and still end up with green or blue eyes.
Contrary to popular belief, it’s also possible for two blue-eyed parents to have a brown-eyed child.
Eye colors depend on the amount of pigment (melanin) found in the iris and how it is distributed. Light gray-blue eyes contain much less pigment than extremely dark brown eyes. And there are many shades of eye color in between.
Some people are even born with eyes of two different colors, a condition known as heterochromia.
Eye color percentages vary according to which population is studied. For instance, the percentage of dark brown eyes found in Asian and African populations will be much higher than in European populations.
And some day, blue may be a rare eye color. This is because more people now select mates outside usual cultural and ethic groups. So when a brown-eyed person marries someone with blue eyes, offspring are more likely to inherit the more dominant brown eyes.
Example of a Human Eye Color Chart
You can view examples of common human eye colors in the following chart, along with some fun facts.