 that you would ever come off scope is when you get what they call eye fatigue. You do get the point where you sit under magnification for so long that your eye will twitch. But that is why you have a spotter. How long? 30 minutes, 45 minutes? It's different for each shooter, right? And how long you've actually been out there, the conditions of the day, et cetera, what kind of glance and glare you have. But the point is, that's why you have a spotter. When you're not on scope, he is on scope.