Why does nobody talk about the mental focus needed for laser-guided pipe alignment?

I was setting up for a long section yesterday and kept getting minor deviations, even with the laser calibrated. It dawned on me that after a few hours, my eyes were straining and I was second-guessing the readings. Maybe it's just me, but idk, I think there's a knack to maintaining concentration during those repetitive checks. How do you guys handle staying sharp on detailed alignment work over a full shift?