First of all, I'm not saying that it's impossible for clone!Syaoran to eat Fai's eye. I just think that isn't the way CLAMP would want it. It's my idea only. I'm not making everyone follow my idea. It's just a theory, as I said.
Secondly, your theory about the clone and the real Syaoran is a bit off. The real and clone look alike, in my opinion. Also, the real!Syaoran isn't in an unchanging state. He's still growing. To me, he doesn't look like a kid in the tube.
In reality, clones are suppose to grow the same time as humans do, but I don't know if CLAMP took this into consideration or not. With your theory, you're saying that at the same time they clone real!Syaoran, the clone was immediatelly that age right?
Oh, I know. I am just saying it isn't hard to see why people drew the conclusion that he ate the eye.
Clone!Syaoran wasn't the same age, but he had the same appearance immediately. If you look here
http://i79.photobucket.com/albums/j147/melipon/cloned.jpg, from chapter 119, you can see that the clone was the same size as real!Syaoran, and we can assume that he had just been recently cloned because it was before real!Syaoran was fully sealed. I don't think Fei Wong cloned him when real!Syaoran was born and then let them both hang out for 9 or 10 years before sealing real!Syaoran....
And I remembered it wrong, but real!Syaoran is definitely a smaller child for quite a while in the tube, because in various places we see him smaller than clone!Syaoran. He started growing later though, before he opened his eyes (Yuuko says "He has awakened" and we see his eyes opening) and before he breaks out of the tube.
For example, during the Shurano/Sharano arc, we see this:
http://i79.photobucket.com/albums/j147/melipon/sidebyside.jpgThere is a size difference and real!Syaoran's face is rounder and more kid-like. He also looks the same as he does when we see in the later chapters when Fei Wong is sealing him, and he is a child there still.
Then we also have this, which I put side by side
http://i79.photobucket.com/albums/j147/melipon/beforeafter.jpgHe looks taller in the later chapters.
We know that time has passed because clone!Syaoran grew at the same rate that Sakura did, and the other characters aged at an appropriate pace in Clow as well and that throughout that time as we can see, real!Syaoran has remained the same size until recently and clone!Syaoran had grown already.
Also, even in clone!Syaoran's dreams he grew, as seen here:
http://i79.photobucket.com/albums/j147/melipon/syaoran1.jpghttp://i79.photobucket.com/albums/j147/melipon/syaoran2.jpgSo real!Syaoran used to look like a little kid until fairly recently in the Tsubasa timeline, and now they're the same size:
http://i79.photobucket.com/albums/j147/melipon/samesize.jpg (I really love this picture
)
http://i79.photobucket.com/albums/j147/melipon/samesize2.jpgPhew. Anyway, I hope that clears up what I was trying to say