(Speaking of nothing... what do you call that which is visible of your eyeball in medical terms? It begins with 'a', I think... Hrrg, it's driving me nuts!)
Okay, this post may be a little gross because it involves human biology. 'Nuff said.
So, I did a quick google search for information on eyes (and found out quite more than I ever wanted to know. Did you know, for example, that every time you blink, your eyelids spread a layer of mucus, oil, and tears over the cornea? This is one of the many ways in which our body serves to protect the eye, seeing as it's amazingly delicate. Additionally, your eye is about the size and shape of a ping-pong ball. It's bigger than what you see. Wouldn't that make it hard for Syaoran to rip out without...ehh....ripping out Fai's eyelid too? Yuck. Even so, I find biology sort of interesting even though I'm not a science girl.) and found nothing in relation to your question.
I didn't come across any terms that referred to the visible part of the eye as a whole.The visible part of the eye is divided into three parts: the iris, the pupil and the sclera. The iris is the coloured portion, the pupil is the black dot in the centre of the iris, and the sclera is the white of the eye. There's also the cornea, which is like the transparent covering, and all the then the eyelid and eyelashes and soforth.
The only "a" word I found was "anterior", which refers to the iris and ciliary body. Could that be what you're thinking of?
So! There is my science lesson on eyes. Probably more than anybody needed to ever know about their eyes. ... >_<;;
Dammit I'm so off-topic. But I got the one little jab in there about Syaoran and Fai, so hopefully I'm alright.
And in further attempts to stay on-topic, I really want X to be finished too, but I think Tsubasa and XXXHolic will have to run their courses before that happens. Clamp has, what, three series' on the backburner right now? Kobato, Legal Drug and X? I'm placing my money on Tsubasa and Holic finishing before X even begins.