How does 3D glasses/vision work?

The way that you see 3D regularly is by the fact that your two eyes are a little offset, one eye sees a slightly different angle than the other eye, and your brain translates that as 3D vision. Now, if you're looking at a 2D media, like a comic book or movie screen, than there is no difference in the two visions that your eyes see, and it's 2D. Now, what they can do is print two slightly offset pictures, each in a different color. Then, using glasses, where each lens filters the other color out, you are looking at one version of each picture with each eye, so together with both eyes you see two offset versions, and your brain translates this into 3D.

If you ever try to watcha 3-D film without the glasses, you see that the screen displays the same thing in both red and blue, but slightly offset. Each lens of the glasses, due to their colour allow you to see only one of the images, red or blue. The closer together the two images are, the more distant they seem. The more they separate, the nearer they seem.

I think 3D glasses work by having the 'lenses' polarised at 90 degrees to each other, so that every other frame on the cinema film passes either one or the other lens. The eyes don't see the individual frames but the combined effect is 3D.

3D Stereoscopic glasses are nothing new. In fact you had them when you were a kid and probably didn't even know it. Remember the ViewMaster™ that showed all the cool Disney characters in full 3d? The ViewMaster™ allowed you to look at two pictures of the same thing taken from a slightly different view point and tricked your brain into seeing one 3d image. In order to see things in 3D each eye must see a slightly different picture. This is done in the real world by your eyes being spaced apart so each eye has its own slightly different view. The brain then puts the two pictures together to form one 3D image that has depth to it. Still want to know how do 3D glasses work? Keep reading! Anaglyphic [ana·glyph·ic /"a-n&-'gli-fik/] adjective -- A stereoscopic motion or still picture in which the right component of a composite image usually red in color is superposed on the left component in a contrasting color to produce a three-dimensional effect when viewed through correspondingly colored filters in the form of spectacles.

it works because of the different colour glasses you were thy block different colours out plus thy use 3 different came rs at different angles trick off light