Eye Colors

Have you ever wondered why your eyes are the color they are? If you have ever taken a biology class, you might have participated in an assignment where you created a chart using your parents’ eye colors to determine what color eyes you and your siblings might have. It seems pretty simple, but today, scientists have a better understanding of what genes are involved in determining eye color by how they control the melanin in your eye’s iris.

Melanin’s Impact on the Color of Your Eyes

The color of your eyes is determined by the amount and quality of melanin that is present within the front layers of your iris. The iris is the colored structure within your eye that surrounds its pupil. Melanin is a pigment that is naturally produced by your body.

At one time, scientists believed that only one gene controlled eye color. Therefore, it was believed that two blue-eyed parents could not possibly have a child with brown eyes. As you might imagine, this could create a little confusion when a child had brown eyes, but both parents have blue. Inheritance of eye colors involves multiple genes, instead of one controlling the production, delivery, and quality of iris melanin.

The amount and quality of melanin in your irises is determined by up to 16 genes in your body’s DNA. However, the primary genes are OCA2 and HERC2, which are in Chromosome 15. OCA2 controls the cells in your body that produce melanin. HERC2 affects how OCA2 works with a certain mutation that is strongly linked to blue eyes.

Eye colors generally range from a very light blue to a dark brown and are usually split into three categories: brown, green/hazel, or blue. Variations exist within each category, which again, depends on the amount of pigmentation from melanin.

Does Eye Color Affect Eye Health?

The color of your eyes could affect your eye health. Originally, it was thought that people with blue or green eyes were more susceptible to cataracts. But actually, it was just that as the lens in the eye became more clouded, it is more noticeable with those colors.

Darker eyes, which have a higher concentration of melanin appear to be more susceptible to developing cataracts. The reason for this may be because the melanin in the iris absorbs more heat, which has been associated with cataract development. While everyone should protect their eyes from sunlight, those with darker eyes should be especially careful and wear sunglasses when in sunlight.

Regardless of what color your eyes are, you should have your eye examined regularly. Call Valley Eye Care Center at 602-955-2700 or schedule an appointment online for an eye exam.