Here it's a small study of three different sets of green eyes. Marvelous combinations of green, blue, brown and yellow make them so unique.
The people I used as models were:
Sharbat Gula (National Geographic Magazine’s cover)
Jensen Ackles (Known from “Supernatural”)
Angelina Jolie (First known by me when I saw her in “Lara Croft”)
I'd like to do something like this for other eye colors, but we'll see