Our lenses were just yellow plastic frames with a "greyed" insert material. There was no attempt to block peripheral vision.
I tried the head tilt/roll and found that I could tilt my head considerably further than I could with the old polarized glasses before loosing effect. A typical head tilt was acceptable, whereas it is not acceptable with my polarized 3-D videos.
The best 3-D I've seen was with the IMAX LCD shutter glasses that alternately close the left then right eye in sync with the movie. The 3-D was very immersive and head postion had no effect at all. But they stopped that years ago.