there's always a Carl. That's just a law of physics or something.
Now I'm thinking about how 3d movies would work for hydras
the glasses alone wouldn't be enough because you'd have to account for multiple head positions
this sounds like a difficult problem, I wonder if anywhere would advertise as supporting "up to four heads!" or something
they couldn't use polarization anymore, of course. so they'd have to use active shutter or something
also you'd have to account for different people having different spacings between the heads or different numbers of eyes per head