I am looking forward to seeing that head!
One thing to note, the reflections seem off to me, could just be me but heres a list of IOR(index of refraction) values for the human eye:
Eye, Aqueous humor 1.33
Eye, Cornea 1.38
Eye, Lens 1.41
Eye, Vitreous humor 1.34
For super real eyes, the values you set should be these or close to them.
Heres a picture of eye reflection: https://johnschupbach.files.wordpress.c ... ection.jpg
(click this link to view the image)
See how the reflection is different over the iris and pupil than it is everywhere else?
I would say go for that effect.
IOR values source: http://forums.cgsociety.org/archive/ind ... 13458.html