Attached Link: My eye

Hi everyone. Thanks for te help on other problems I have had so far. Now, I need more and figured some one here would be able to help me! Anyway, I am very interested in eyes and I like making them in Photoshop. But the problem is, that an eye is probly the most detailed object ever and it is very hard to make. I need some help, some tutorials or whatever you guys have for me to help me make a better image! Look at my eye I have made. I am pretty satisfied with it so far BUT there are missing details! Loads in fact. I need to make a more bumby eye. Notice the light green in my image. I tried to make it but it is impossible. I have noticed that on real eyes there are some craters kinda details in the iris. Any help on how to make that? This guy told me he had a mask for it but never showed me anything... I wanna be making some different eyes for Poser and hope any of you will be able to help me.. You will be granted with the finished file ;) Thanks so far! Rune