**Try bringing the highlight on the eye surface down to a light grey. It might help offset the whiteness in the eyewhites.
A bit darker on the outer circle of the iris. It's still hard to see that and it's very noticable in real eyes.
I would also suggest that you make the diffuse on the pupil white to show the pupil on your texture map if you have the pupil blending in naturally on that.
As for realistic eyewhites, I strongly suggest using Sarsa's resource for V4 found at Daz. The eyewhites in the pack are really wonderful.
You have really good looking lacrimels in there. Reflections as well. I like them.

I made an eye pack for V4 that took me lots of research and experimenting and people seem to like the results. As was mentioned, it would almost take a manual to tell you how to do it. Examples explain it better to me. If you would like more info, IM me. I'm willing to help.**