There's just no way
It has been proven over and over again that sighted fire is superior to unsighted fire.
I can see he value of point shooting with your first shot at very close range (3 yards or less), but if all possible then acquiring the sights will lead to more precise shot placement.
Is not the main thing we all stress shot placement? If you want your shots to be well directed at the sternum and brain, use your sights.
"No free man shall ever be debarred the use of arms."- Thomas Jefferson