How to create more realistic eye textures

Hello everyone;

I am experimenting with generic creation of eye textures. So i followed some good tutorials and did some further experiments, but what i get out so far still does not look very realistic. see my attached example.

I do have one particular problem: The transition between the black center and the lighter iris part is much too sharp. the black object in the middle is nothing else than a sphere scaled down in z-direction to a flat disk. now i would like to make the edge of the disk partially transparent, but i don’t know how i can achieve that and if it really helps to make the eye look more realistic.

The other problem i have, is the thickness of the hair strands, which i use to simulate the fine texturing of the iris.
I would like to make the hair much finer and i would like to get it a bit more curly, so thaty it ressembles a bit like the eye here:

Anyone could give me some hints, how to get such effects as seen in the picture from wikipedia ?

thanks a lot in advance



Try texturing it in layers.