Quick, what's your eye colour? If you answered anything other than "brown," then, scientifically speaking, you're wrong.
A few recent studies on eye colour have conclusively shown that everyone has a certain amount of brown in their irises. Just how much brown a person has determines the colour s/he thinks s/he sees in the mirror.
The key component in determining eye colour is melanin. You may have heard of this pigment before in relation to skin and hair. It's true that more melanin contributes to both a darker skin pigment and hair colour, but it's also responsible for the darkening of the eyes' irises.
The tiny melanin cells within a person's irises are officially called melanocytes. These melanocytes are always brown. Every single person has a certain amount of melanocytes in each iris, which means everyone's eyes are technically brown.
More melanocytes in the irises means darker eye colours. How our irises interact with light determines what colours appear in our irises.
Since melanin naturally absorbs light, it stands to reason that people with more melanin will have darker brown irises. The more melanin, the higher chance a person will have dark brown eyes.
People with blue eyes, however, have less melanin and produce more light "scattering." This means that blue-eyed people's irises reflect light instead of absorbing it. This "scattering" process sends out shorter wavelengths, thus resulting in the blue pigmentation.
Green-eyed and hazel-eyed people generally have a medium amount of melanocytes in their eyes.
Using these findings, scientists now know why most babies are naturally born with bright blue eyes. A baby's eyes are blue because the melanin hasn't yet fully formed. Most babies' eyes will morph over time as more melanin accumulates in the irises.
Scientists are also using these studies to figure out how children can have such radically different eye colours from their parents. People who both have dark eyes and produce children often give birth to a child with blue, green, or hazel eyes. This is because the child has less melanin in his/her eyes.
So, just how rare is each eye colour variation in the human species? According to the most recent data, brown remains the most common eye colour at 55 percent of the global population. Hazel-eyed people make up around 7 percent of the world's population, while blue-eyed people constitute around 8 percent. Green eyes are quite rare, with only about 2 percent of the world's population. Silver and amber eyes are by far the most rare eye colours. Silver eyes are generally only found in eastern European countries, whereas amber eyes are generally only found in certain Asian and South American nations.
The optician bringing this melanin study to light is none other than Dr. Gary Heiting. Dr. In addition to his editing work, Dr. Heiting has worked for companies such as Park Nicollet Medical Center, Eau Claire LASIK, and Ophthalmic Surgeons & Physicians, Limited.