How can someone have two different colored eyes?
According to the experts at Scientific American.com, it was once believed that eye color was controlled by a single gene and inherited in a straightforward fashion (remember Mendel from high-school biology?). These days it’s not quite that simple. We now believe that eye color is a polygenic trait. Eye color is determined by the amount of melanin, a dark brown pigment, present in your irises. Blue eyes are due to a lack of melanin, while brown eyes indicate melanin-rich irises. Thus, people with darker hair and skin have higher levels of melanin and tend to have brown eyes, while people with lighter hair and skin have lower levels of melanin and usually ha