This battle is famous and notable for the use of the English longbow in very large numbers, with English and Welsh archers forming most of King Henry Vâs army. The battle is the centerpiece of the play Henry V by William Shakespeare.
But to the point, the English archers were taught to not look at their human targets on the battle field, but to look through or past them when aiming. The good ones could almost "loose" their arrows and hit the target with their eyes closed.
I remember reading about the ‘hypnotic stare,’ where you look at the person, but are actually focusing your eyes ten feet behind them. It was also useful to give the wife the impression I was listening to her talk while my ears were tuned in to the football game.