Very little is certain, but...

I took this eye out from a piece of a portrait [link] I am working on and then did some more modifications to it. I highly recommend any portrait artists to go into extreme detail at least once, it might drive you a bit crazy but it's worth it for what you learn.

I named this picture after a song by
Spook the Horses
[link]
Have a listen it's great!

This is 100% digital painting, using various skin texture brushes etc. The eyeball and the lashes are done just using the 'basic' photoshop brushes. I used the pen tool for the glasses frame.