Ditto to what gunnman said. The brain is only getting the input the eyes provide.... old guys like me need vision correction to see the front sight bouncing clearly over the zero zone. In my case it was an accidental outcome of eye surgery that put my fixed focus distance (from cataract surgery) right on the front sight. I should have tipped the eye doc more.

Bill's drills at varying distances and the same with a plate rack if you have access to one...

Wally