I think it is the massive size of the IMAX screen, and relative exaggeration of the left / right isolated images that forces the brain to perceive it. In real

I think it is the massive size of the IMAX screen, and relative exaggeration of the left / right isolated images that forces the brain to perceive it. In real life I struggle to tell the difference if I close my bad eye - which leads me to think I don't see in 3d. Brain perceives depth purely through focus; when looking at this phone as typing, the only change if closing the bad one is peripheral vision (Venn diagram/what good eye can't see) being dropped.