Why do I have blue eyes when both my mother and father have brown eyes?

Each person has two genes for eye color. When a person has two identical genes, he will have eyes of that color. Another person may two different genes, and she will have eyes the color of the dominant gene. With eye color, the gene for brown eyes is dominant (B). The gene for Blue eyes is recessive (b). If a person has one B gene and one b gene or two B genes, then that person will have brown eyes. If a person has bb eye genes, then the person will have blue eyes.

Parents with Brown Eyes and Recessive Genes

Parents with Brown Eyes and Recessive GenesIn this diagram, both the mother and father have brown eyes, but they both have the recessive gene for blue eyes as part of their genetic makeup. There is a 1 in 4 or 25% chance that their child will have blue eyes.

One Brown Eyed Parent with Recessive Gene

One Brown Eyed Parent with Recessive GeneIn this diagram, the mother has brown eyes with the recessive blue eye gene and the father has blue eyes. There is a 1 in 2 or 50% chance that their child will have blue eyes.

Brown Eyed Parent without Recessive Gene

Brown Eyed Parent without Recessive GeneIn this diagram, the father has blue eyes and the mother has brown eyes without the recessive gene. In all of the possible combinations for the children, there is one of the dominant B genes. All of the children will have brown eyes.

The results would be the same in diagram 2 if the Mother had blue eyes and the Father had Brown eyes with a recessive blue gene, or in diagram 3 if the Father had the brown eyes and the Mother had blue eyes.