Photoshop CS-CS6, CC
Photoshop Elements 3+
Rings, striations, and various other effects that you can put together to create a realistic looking iris. Includes a base layer for the basic eye color, various layers for adding rings of color, some brushes to add imperfections, striations (the ridges and “burst effect” look that you see on irises), pupils, and even reflections of light.
I noticed there were a few other sets out there like this (not until after I got the idea and made them myself!), but I doubt they're as high resolution as this set is, or with as many options as I have in this set!
I have a tutorial on how to best use these on YouTube: www.youtube.com/watch?v=ZxQ52e…
Licenses available for those who can't credit: www.obsidiandawn.com/iris-part…