Its minor, I would of done a far lot more with the eye if I was bothered, and to me your/my glare is far to big and bright.  I think another colour or two could be added to help the transition. It doesn't matter to me at all though, what you want and decide to doto this is ultimatly your in your hands. I just hope my edit helps in some way.

I'm talking about the shading on it... duh

 You did the glare...not me.

I've only worked with a reference once... and it didn't turn out to great. The "skin" was just placed for... uh... filler purposes, although, I did begin to think about shading it... Your edit it is pretty good... although the glare on the eyes looks horrible--in my opinion.

Anyway, I'll remember when/if I ever get around to fixing this.

Hey there Cherry/Aiko, I must say that you took on a part of the face that feckin annoys me, but I found time to make an edit. There are a few problems with the eye you made, one I'm not sure if you were going for a manga type eye or more realistic, second it lacks volume, its very flat as it is, and third I'm bored. So I here's one edit for you.
 

EDIT: What? who changed the url? /EDIT

I added the yellow lighter tone to add more volume in areas where it could be a tad brighter, but its more of a replacement colour. But the most important thing I did was reference.

[http://pictures.directnews.co.uk/liveimages/Eye_1092_18330321_0_0_8725_300.jpg]

yes, i think it looks better.

There, I fixed some things. Does it look better?

could use some AA with an existing color.

maybe also fixing up some jagged lines.