I agree with CoachJim. I use "blind" bowling quite frequently to find miscues in my game. I actually even use it in league if I start missing my target, gripping the ball, or falling off the shot I just do one shot eyes closed and I am back in business.

You will notice that with your eyes closed you hit your mark quite often, actually probably as much as you do with them open. After a while you will begin to see by feeling rather than seeing by looking. You will begin to know you missed inside even before you open your eyes, you can feel different release points and you might even begin to call out pins you will leave as the ball comes off the hand.

This game is about feeling, and what better way to train you to feel than to make your body feel because it can't see anymore.