Polarized 3-D glasses are the most common type of 3-D glasses. They work by filtering out light waves that are vibrating in a particular direction.

Each lens of a polarized 3-D glasses is made of a special type of plastic that contains long, thin crystals. These crystals are aligned in such a way that they only allow light waves that are vibrating in a certain direction to pass through. The other light waves are blocked.

The left and right lenses of polarized 3-D glasses are aligned in opposite directions. This means that the left lens only allows light waves that are vibrating vertically to pass through, while the right lens only allows light waves that are vibrating horizontally to pass through.

When you watch a 3-D movie with polarized 3-D glasses, the images that are projected onto the screen are actually two slightly different images. The left image is polarized so that it can only be seen through the left lens of your glasses, and the right image is polarized so that it can only be seen through the right lens of your glasses.

Your brain combines the two slightly different images into a single, three-dimensional image. This is what gives you the illusion of depth when you watch a 3-D movie.

Anaglyphic 3-D Glasses

Anaglyphic 3-D glasses are another type of 3-D glasses. They work by filtering out light waves based on their wavelength.

Each lens of an anaglyphic 3-D glasses is made of a colored filter. The left lens is usually red, while the right lens is usually blue.

The images that are projected onto the screen for an anaglyphic 3-D movie are also slightly different. The left image is tinted red, while the right image is tinted blue.

When you watch an anaglyphic 3-D movie with anaglyphic 3-D glasses, the red filter in the left lens blocks out all of the blue light from the left image. This means that you only see the red image with your left eye. The blue filter in the right lens blocks out all of the red light from the right image. This means that you only see the blue image with your right eye.

Your brain combines the two slightly different images into a single, three-dimensional image. This is what gives you the illusion of depth when you watch an anaglyphic 3-D movie.