Board Thread:Naruto Discussions/@comment-26107879-20181004003653/@comment-34194151-20181007024827

Increasing your speed with the body flicker will not induce tunnel vision because it doesn't push the user over their visual perception threshold. kakashi became faster than his kid self and he is able to use his faster body flicker without any issue. When you train your speed naturally there isn't a tunnel vision effect, because your body and mind seems to calibrate with your speed. but chidori seems to cause the tunnel vision effect because it has some weird multiplier that causes your current body limits to be surpassed. That's the only thing that makes sense with Gai's statement. If it was the body flicker then the characters would be talking about kakashi slowing down his body flicker and not telling him to throw away the technique all together. Minato himself is faster than chidori kid kakashi and yet he didn't suffer tunnel vision when he saved kakashi. it's a ratio of your speed to your body's limits.