The genetic marker in this report is located near a gene called OCA2 that affects how much brown pigment your cells produce. People with 1 or 2 copies of the A variant of this marker tend to have more brown pigment in their eyes, so they are likely to have darker eyes.
The ancient origins of eye colors
Early humans had brown eyes. But at some point in history, a baby was born with a genetic variant leading to a strange new eye color. Today, most light-eyed people carry that same genetic variant.
What gives your eyes their color?
The color of your eyes depends on how much eumelanin they have. Eumelanin is a brown pigment molecule. It looks dark because it absorbs the sunlight — so more eumelanin leads to darker eyes. It's also the same molecule that colors your hair and skin, though different genetic factors can affect how much brown pigment you have in each place.