Did you know what's in an iris?

The iris controls the amount of light entering the eye by adjusting the size of the pupil. The iris has a Pupillary zone, Ciliary zone and a Collarette.

Did you know that Brown eyes have the most color?

Brown eyes are the most popular, and have the most pigment, in the form of melanin. There are actually 2 kinds of melanin in the iris. 

Did you know that Blue eyes lack color?

The iris won't contain any blue pigment, but will appear blue due to the Tyndall effect, which is similar to Raleigh Scattering, the same effect that makes the sky blue

Did you know that there are no green eyes?

The green color isn't due to green pigment in the iris, but rather a combination of yellow and a lack of pigment which appears blue.