Not changing the ball flight...reread...changes with different ball flights...If the horizontal axis of the eyes are parallel to the plane line...it's easy to "trace" a straight plane line...If the horizontal axis of the eyes rotates to the clockwise ..so does the hand path and plane line tend to like to shift cross-line right.....likewise a counterclockwise rotation of the horizontal axis of the eyes the tendency for the hand path and plane line to shift cross-line left...
"The golf swing begins and ends with the eyes and the hands"....Mac O'Grady