How do 3D glasses work?

Answer 1

Polarized 3-d glasses create the illusion of three-dimensional images.

3-d images are actually two images that are projected superimposed onto the same screen through orthogonal polarizing filters (one on top of the other).

The viewer wears the 3-d glasses restrict the light that enters each eye. They also contain a pair of orthogonal polarizing filters. Each filter passes only that light which is similarly polarized and blocks the other orthogonally polarized light, each eye sees only its separately polarized image, producing a three-dimensional effect.

In simpler terms, of the two superimposed images, one image enters the right eye and the other enters the left eye, creating a 3-d effect. Normal pictures are not polarized, and hence, looking at them through the 3-d glasses will not produce any effect.

If you take off your 3-d glasses in the cinema hall, the picture will look a bit blurry at the edges because of the two superimposed images.

Answer 2

The red and blue lens actually trick your eyes, because your eyes can't make what picture they're looking at, making it 3-D.