Definitely learn to shoot with both eyes open. Opening a closed eye during or at the shot can only lead to you moving the bow to see the shot, which is a form aof target panic. Practice makes for better shooting. Either way, one eye or two, you should not have to see your arrow go. All you have to do is execute the shot well and follow through and tell yourself that the arrow is where your sight pin was when the bow went off. Some of the best shots you'll ever make are those where you never see the arrow go.