This is very very simple and neat little trick for creating that 'glassy' and bright look in the eyes. I've personally always wondered how people do this and now I know and I'm gonna share it with you guys. =)
I don't know if this is the best possible example-photo, but this is all I've got atm. This tutorial is only about the effect in the eyes.
What you'll have to do is:
1. Duplicate the background layer
2. Use the dodge-tool for the eyes: first the shadows, then mid-tones, then highlights.
3. This might make the eyes pretty unrealistic so you might want to adjust the layer's opacity a bit.
There. Very simple. I think it can bring out the little blinks pretty nicely. =)
Hope this is useful to someone else too.