Ah, see, there's the flaw in his analysys. 50 meters is the range of his all around vision. He also has 1 mile see through vision, but it's extremely narrow. It's like, okay, I can see a mile away, a spot 20 feet wide. And even doing that has to concentrate.
Kido doesn't have to be a mile away. He just has to be more than 50 meters away and not be DIRECTLY in front of Neji to avoid being seen.