I think this is kind of a thing for a lot of stereoscopic 3d technology.
I could play the virtual boy, 3ds, watch 3d movies, etc. for hours without issue, and other people can't take it at all.
I don't know what factors play into that, maybe it's genetic, maybe there's some kind of skill/technique/habits about how you focus your eyes, or how often you blink, maybe it's just luck of the draw that your pupil distance is just right or wrong. Maybe it comes down to something ridiculous like how many hours you spent trying to make sense of Magic Eye books when you were a kid.
One of my favorite scary facts about the moonies that I don't see talked about much is that a couple of the founders sons had a falling out with the church, and went and started their own, even crazier church. They made the news a few years back doing some rifle blessings and some kind of mass wedding ceremony (also with rifles)
Not for nothing, they also own kahr firearms