Cameron foresees a future where 3-D movie technology and implementation become "'much more pervasive that we are thinking now.'" In a few years, he says, most computers and DVD players will be able to show stereoscopic movies. He advocates filmmakers start shooting now for such a future. Except quite a few people can't see very well in 3-D, and some can't see in 3-D at all. (And some can't see anything at all, of course, but that's for another article.) There are people with strabismus or amblyopia whose eyes don't look in quite the same direction, for starters. Then there are the cyclopses and all the kids who got frisky with a BB gun once too often, and the people who just plain get queasy when they watch 3-D movies.

So that's how it's going to happen. Everyone who can watch 3-D movies will go to certain theaters, and everyone who can't will go to others. People with stereoscopic vision will hook up with others of their kind at the concessions stand, while those of us in the 2-D theaters will hook up with other people with flat vision. Over many generations, we'll become genetically distinct. I just hope we can all live in peace together. If it comes down to a fight, I'm screwed. I don't have the depth perception to land a good punch.