Have you ever gazed into someone’s eyes and loved just how blue their eyes are? However, no matter how much you love those aquamarine eyes, they just aren’t actually blue. In fact, they are brown and actually, all eyes are color brown – any difference just boils down to the presence of a substance called melanin.
The colored part of our eyes, the iris, is composed of two layers – the stroma, which is the anterior layer, and the epithelium, which is the posterior layer. The stroma consists of cells that contain melanin, non-pigmented cells, colorless collagen fibers, and other types of tissue. The epithelium, on the other hand, consists of only two layers of pigmented cells.
The melanin and the collagen fibers present in the iris determine eye color.
It is the stroma that gives the iris its color. Sometimes, it contains excess melanin and at times there are excess collagen deposits. It is the balance between these two factors that decide the color of the iris.
People with brown eyes usually have a high level of melanin in their stroma. As such, light entering the eyes is absorbed, without regard to the number of collagen fibers present. Those with green eyes, on the other hand, do not have much melanin in their stroma and at the same time lack collagen deposits. As a result, some light scatters and only a small amount is absorbed. The color produced, when combined with the brown pigment, results in a greenish hue.
Blue, green, and gray eyes – all of them are actually brown!
Now, people with fascinating blue eyes possess a completely colorless stroma without any pigments and lacks any excess collagen deposit. Consequently, light that enters the eyes is scattered back into the environment, turning the iris into a lovely blue color.
Most babies are usually born with blue eyes.
This is the same reason why many babies have blue eyes. Their body have yet to produce melanin and once they are able to do so later in life, their eyes change color.
Interesting, right? So remember, all eyes are brown!