RE: 1 eye or 2
The following is from a backyard shooter / bowhunter:
I don't think about it, but I close one eye. I shoot a bow like a pistol, focus is on the front sight. I know where the pin is on the target, but clear focus, especially at release, is on the pin. I only see the arrow in flight at longer distances.If I don't keep focus on the sight my shot doesn't hit where I want.