It's included as a MAT option for Millawa 8, which you can get on here in the
BUNDLE.
It's confusing though, because it's not an option that shows up on the content tab or Smart Content. Instead, you have to select the Iris surface tab and browse the directory and you'll see it as a texture option there.
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Honestly though, it's really easy to make your own custom eyes by just PhotoShopping the Iris maps. It's certainly easier making simple geometric graphics like this, then doing it the other way around and trying to paint photo-realistic eyes, lol.
I made this one in less time then it took to render it... about 10 mins in PS. I just put a purple background on one eye, grabbed a sci-fi theme target image with transparent background off Mr. Duck-Duck-Go and changed some of the colors.
EDIT: I forgot to find and edit the pupil map too
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