Jack Nicklaus and Tom Watson always thought that you need to have your eyes over the path of the ball as you putted. Looking directly down at the ball was critical to Jack and Tom. You can check and practice your alignment by taking your stance, then take one hand off of the club and with another ball in that hand, drop it straight down from the bridge of your nose. It should land on the ball you are putting. If it was good enough for them we have to try it.