seriously. what's all this talk about the edo tensei bringing back the person in their "prime?" did we forget about good ol' chiyo? LOL
i'm pretty sure the way the edo tensei works, is that it rbings back the person in their last "out-of-battle" condition; for example itachi would be brought back how he was before his fight with sasuke, whila nagato would be back in his last condition before facing konoha/naruto.
under this assumption, we can say itachi eyesight is probably slightly blurry, but he's so badass he can still own like the pro he is, and he won't go blind while in edo mode.
now about nagato, why the heck did he stay in skeleton mode if all he had to do is absorb some bijuu chakra, maybe the akatsuki members could've lend him some chakra, i mean sure he would still have problems walking but he would look a LOT more healthier lol. maybe i'm missing something. maybe he would make him look too weak, or he has to still a skeleton as long as those black rods are in him, ahh i don't know, i don't get it. lol