Re: Kakashi's kamui does not affect his eye sight. (FACTUAL PROOF) by Sasuke..
But Obito said to Sasuke that he had gone blind due to Susano. This was directly said. Tsukuyomi is such a powerful genjutsu. Itachi also feels it as 3 full days in his mind. Even if he doesn't get tortured or anything, it will have an impact on him as well. This means Tsukuyomi isn't a jutsu suited for fights, where you are greatly outnumbered. However, in a even match or just 1v1, it is an exceptional jutsu, however, this is in the middle of Konoha so...
Originally Posted by hanothemano
Whether Kisame refers to this (since Kisame seemed pretty careless about getting in a big fight), or he refers to the damage to the actual eye, I do not know.
However, it is pretty damn obvious that it is susano that makes the difference in your blindness. Cause if not, one could simply spam the same jutsu - like amaterasu, but that would only make you go blind on 1 eye, since it is used by 1 eye alone. Where Susano needs both eyes.