Billiards! Everyone here will surely suggest frequent breaks, which is great advice. I'm going one step further to suggest that you play billiards during those

Billiards! Everyone here will surely suggest frequent breaks, which is great advice. I'm going one step further to suggest that you play billiards during those breaks. However, you must play correctly. Be sure to line up shots with both eyes open. Alternate your focus between the tip of the cue, the cue ball, the object ball, and the target pocket until you are confident your shot is aligned. Doing it this way will strengthen your game, as well as your eyes.