The iris contains the pigmentation that determines our eye color. Eye color is developed through chromosomes, which each parent randomly passes a chromosome for eye color. Children can have different eye colors than their parents or have the same as one parent. It all depends on the genes passed. You need to know eye color is developed first if you are to understand why your eyes are a certain color and it gives a lot of information on how they are passed.
The reason you can have brown eyes is because of the amount of melanin in your eyes. If you have a concentration, you will have brown eyes, while if you have a low concentration you will have blue or light-colored eyes. It is also hard to determine if you will have a certain eye color because of the 16 genes or more that are associated with it. I chose this article because it explains how you could end up with brown eyes.
Brown eyes are dominant over blue eyes. If one parent passes a blue gene and another passes a brown gene, the brown will override the blue and the child's eyes will be blue. This website tells you if brown eyes are dominant or recessive.
The pigment that make brown eyes, melanin, can prevent some cancers and it is also one of the most common eye colors. People with brown eyes have more anxiety than other people and have a higher pain tolerance. This website tells you some facts about brown eyes and how melanin can effect you.