To check your eye position, setup in your normal putting posture. Without changing your posture, drop a ball from the bridge of your nose. Where it lands will be the proper address position for the ball under your eyes.
This ball position will ensure a consistent setup and help with alignment.
franklygolf 
better yet place an old or new cd on the ground and put your ball in the center hole, look down if you see your eyes your perfect. adjust accordingly.