First off, the eye is "gorgeous!" The subtle details you've given are striking and pretty much perfect! That is definitely the focal point, which assuming your comments, was the intention. The eyelashes are also done very well. That helps further strengthen the the beauty and detail put into the eye.

The only thing as far as improvement would be the work outside the eye...referring to the face and background. I don't feel this is anything to be treated negatively, merely, I feel after looking at how perfect the eye and lashes are that the rest maybe just needs a little more time spent on it to create that more "photo-real" sensation.

In a nutshell...the eye and lashes=amazing...they look real. The rest of the piece needs that. Add that, and this is one of the finest paintings I have ever seen!

Overall...fantastic! It's obvious that a great deal of time was put into this...and it shows! *applaud*