>>Do you still need the cardboard glasses?
>
>These look more like plastic sunglasses - no red lens and blue lens but yeah, you need the glasses. ( don't imagine that will change until they go to some holographic technology. )

If that's the IMAX technology, it's polarized (not too much, though (*) :). The left, um... can't call it glass, can't call it lens... the left eyepiece has the plane of polarization bent 45^o left, and the right one 45^o right, and so do the lenses on the projector, which then means that the left and right images are projected in two beams of polarized light that have planes at right angles to each other, so the left lens sees the left image but cancels the right one out and vice versa. Straight out of my matricular work when I graduated high school.

(*) accidentally, I had my own polarized glasses at hand, so I could check - when looking at a pair of IMAX goggles at 45^o to the plane of my eyes, one of the... eyepieces should be completely dark. It never gets completely dark, no matter how I turn them - which is not the case with any other polarizing filter I tried, they all look completely dark when I put them so that their plane of polarization is horizontal (the shades you can buy are oriented vertically).