I had some troubles with the glass shader covering iris, but i tested some combinations and finally getting something.
Here some steps i did:
First, following Mikey tutorial with a glass shader in the end of nodes:
Black iris
so i tried with a tansparency shader:
Better, but i didn’t liked the effect when the eye is viewing from side, so i added a mix shader and tested combinations:
Still same as before
Approaching the aim, but the iris color was too ease to my taste.
I added an emission shader to the iris material:
Looks ok, but still not enough in my opinion (for a realistic eye)
I will also share a tutorial i followed long time ago to get this 2nd eye:
