Why Do Some People Have Blue Eyes, and Others Have Brown?
The color of your eyes has to do with your genes. These genes account for the most common colors — green, brown, and blue. Genes are tiny chemical messengers that carry such family traits as skin and hair color, as well as eye color.
Genes are passed along to you by your parents. Chances are you have the same color eyes as one of your parents. What if you’re the only brown-eyed member in a blue-eyed family?
You may find out how you got them by tracing your family tree. One of your grandparents may have had brown eyes. Gene traits are passed from one generation to the next. This is called heredity.
Eye color is not an example of a simple genetic trait, and blue eyes are not determined by a recessive allele at one gene.
Instead, eye color is determined by variation at several different genes and the interactions between them, and this makes it possible for two blue-eyed parents to have brown-eyed children.