Had the insane idea of trying to make a procedural Iris material myself…
At first my problem was making the “lines” go toward the center of the circle…
But then I found this “Follow Active Quads” trick:
By doing this, allows the lines of a Wave Texture for example to go towards the center.
And a Gradient set to Linear to be a Circle so I could define the Pupil.
And like this I could start my journey…
And it’s going pretty good I guess.
May not be the most accurate Iris but the result is acceptable I think.
A render of a Blue Iris 
