Its easy to feel some anxiety when thinking of buying a 3D HDTV but before you break a sweat check out this article about how 3D technology actually works. 3D passive poloarized glasses that are used in the theater or a projector that you are using in your best home theater room projects two images on the screen while the glasses polarize the light creating the 3D Image and a passive 3D TV uses a filter with alternating horizontal and vertical stripes, separated by a black, picture-blanking bars that is called circular polarization.
Although you may not know how passive 3D glasses work, you have almost certainly use them before. This is the type of technology that movie theaters typically employ. This is because the nature of cinemas allow for two projectors and thus two images to be projected, and because passive 3D glasses are significantly less expensive. So this is how it works: in each theater to projectors are trained on the screen. When the time comes, each is loaded up with a different version of the feature printed on polarized film. Moviegoers then wear polarized 3D glasses; this makes it so that each eye only use one set of images. It is as such that passive 3D glasses are able to simulate stereoscopic vision.
So in a nutshell passive 3D glasses are able to simulate stereoscopic vision which allows us to see things with depth. By having each eye seeing a different 2-D image our brain is then tricked into seeing a 3D image.