For most people, one eye is much more dominant in seeing alignments than the other. Typically, right-handers are right-eyed, and vice versa. About 5% are "cross-dominant" (e.g., right-handed and left-eyed) and some are "ambi-ocular" (no dominant eye). To aim and sight well, it helps to locate your dominant eye directly over your cue. For cross-dominants, this may call for some adjustments in stance or neck/head angles. For ambi's, the stick will be under some spot between the eyes. Here's how to test yourself: Hold your thumb up at arm's length, visually blocking some distant object (for example, a clock or a lamp). Don't focus on your thumb; focus on the distant object. You'll see a ghost of your thumb, since your dominant eye will be in line with both your thumb and the distant object, while your non-dominant eye will be seeing past your thumb, directly toward the distant object. With one eye seeing the thumb and the other not, you get a ghost. The ghost is centered on the distant object because your dominant eye is the one that tells you what's lined up with what. So, when you close your non-dominant eye, the thumb becomes solid instead of ghostly, since the dominant eye is looking directly at the thumb. When you close your dominant eye, the thumb appears to jump to the side because the dominant eye (that was making the thumb line up with the distant object) is not in use. Stroke into a mirror to see where your dominance spot is, relative to your shaft. It "should" be directly over the shaft. If it's not, but you're not having difficulty aiming or sinking balls, don't worry about it.

there is none in the game of pool you have to use both of your eyes for depth and alignment dont listen to "you should have your dominate eye over your cue" your not shooting a gun and your cue should be placed center and paralell to your chin but its all in whats comfortable for you and your main aspect on pool is your stroke which if you get a few bad habits there for muscle memory thatll take a long time to repair also in pool you dont just focus on the object ball or in a distance dont let people fool you thats like saying if your left handed throw with your left leg in front and vice versa i my self am abidextrious (multicoordinated) i usually write with my left but i can right the same with my right i usually throw right handed but i can throw left as well im off topic a little but trust me Im a physicist