I modeled in Maya, textured in Photoshop and Substance Painter, and rendered in Marmoset Toolbag 3. I got the picture of the iris from here.
Update as of 7/7/20:
Kudos to Tom Römer for his idea to use a model head from The Wikihuman Project. I decided to do one more thing and place my eyes within one of the sample heads. I rendered in Marmoset and brought into Photoshop for some retouching and addition of eyebrows since I couldn't find the texture set with them on the face. :)