How to Make Your Own 3D Glasses
To make your own 3D glasses, start by cutting out a frame from poster board or stiff card. Then, cut lenses out of cellophane or a CD box that are slightly bigger than the eye holes on your glasses so you can tape them in place. To color your lenses, use permanent markers to make one red and the other blue. Tape the red lens on the left eye hole and the blue lens on the right before testing out the glasses with your screen. If the 3D effect doesn't work, alter the hue and tint on your monitor until the blue becomes invisible to you.
Create or reuse a pair of glasses frames. The sturdiest option is a pair of cheap glasses or sunglasses from a drugstore or dollar store, with the plastic lenses popped out. At that point, you're not saving much money compared to ready-made 3D glasses, so many people prefer to use poster board, cardstock, or ordinary paper folded in half. A sturdy poster board such as oak tag will last longer than other paper options. Cutting and folding the glasses frame is pretty intuitive, but you can print, cut out, and trace this template onto heavier stock if you prefer. Cut out clear plastic to use as lenses. Just about any type of clear plastic should work. Whichever you choose, cut it out to be slightly larger than the eye holes in the glasses frames, so you have room to tape them together. Here are a few commonly available options: Cellophane. This is the thin, flexible plastic sometimes used as "windows" on food packaging, or to wrap CD cases. Transparency sheet for overhead projectors. You can buy these at office supply stores. A hard CD "jewel case" itself. This should only be cut by a competent adult, due to the risk of shattering. Score the plastic repeatedly and lightly with a utility knife until there is a deep groove, then bend lightly to snap it apart. Acetate sheets (also called acetate film) are available at art supply stores or theatrical/stage lighting stores. These already come in red and cyan, so you can skip the coloring step. Color one lens red and one lens blue. Use permanent markers to color one side of each lens. These glasses work best when you use cyan instead of blue, but blue is a more common marker color and works pretty well. If the color looks patchy or inconsistent, smudge it together with your finger. The room should look darker when you look through the lens. If it's still pretty light, color the other side of the lens as well. Tape the lenses over the eye holes. Red goes over the LEFT eye, and blue goes over the RIGHT. Tape the lens to the frame, and take care not to tape over the lenses themselves, or you'll get a fuzzy image. Adjust your monitor's hue and tint. Try on the glasses and look at your 3D image. If you are viewing a TV or computer screen and you don't see the 3D effect, adjust the monitor's hue and tint settings until the blue on the screen becomes invisible through your right lens. It should be obvious when this happens, since the image will suddenly "pop" into 3D. Use these glasses to view red and blue 3D images. Anaglyph glasses are the oldest form of 3D image technology. The same image is drawn once in red and once in cyan (blue–green), slightly offset. When viewed through glasses with the same colored lenses, each eye can only detect the image of the opposite color. Because your two eyes are detecting what looks like the same image from slightly different perspectives, you interpret it as a real 3D object. Some 3D DVDs (but not BluRay) and games that advertise "anaglyph" or "stereoscopic" modes will work with these glasses. Search online for "anaglyph" videos and images to find more 3D content. Most 3D TVs and movie theaters use different technology. If a 3D screen or image contains any colors besides red and cyan, these glasses will not help you. Learn about polarized glasses. One type of 3D glasses commonly used in theaters uses polarized filters for lenses, and special projectors that polarize light. Think of the polarizing filter as a barred window: light oriented (polarized) vertically passes between the bars and reaches your eye, while light oriented horizontally can't get through the bars and gets reflected away. With the "bars" over each eye pointing in different directions, each eye picks up a different image, and your brain interprets the two images as a single 3D image. Unlike the red-blue glasses, this image can contain any number of colors. Make your own polarized glasses. Making these glasses at home is probably more expensive than buying a pair, especially since any theater experience or TV that relies this technology probably comes with a pair of glasses. But if you're interested in the project, purchase a sheet of "linearly polarized" or "plane polarized" plastic film. Rotate the film 45º from the vertical, then cut out a lens. Rotate the film another 90º in either direction, and cut out the second lens. This is the most common design, but you may need to rotate the lens while looking at the 3D image to see what works. Just make sure to rotate both lenses at the same time, since they should always be made from film oriented exactly 90º apart. The actual explanation of polarized light is more technical than described above. Modern 3D glasses usually use circular polarized light, which doesn't require the viewer to keep his head still while watching. To make these lenses at home, you would need one sheet of counterclockwise circular polarized plastic, and one sheet of clockwise polarized plastic (also called left- and right-handed). This is more expensive than linear filters. Understand synchronized glasses. Sometimes called "Active 3D," this technology requires advanced design that can't be copied at home. In order to send a different image to each eye (which is the cornerstone of all 3D technology), the television monitor switches rapidly between two different images, many times per second. The special glasses you wear while watching are synchronized to the television, and each lens alternates between dark and clear at the exact same time, using tiny liquid crystal cells and an electrical signal. This is considered one of the most effective 3D glasses for comfortable, long-term use, but it's just not feasible to make these in your basement, let alone the television set programmed to synch with them. 
Create or reuse a pair of glasses frames. Cut out clear plastic to use as lenses. Color one lens red and one lens blue. Tape the lenses over the eye holes. Adjust your monitor's hue and tint. Use these glasses to view red and blue 3D images. Learn about polarized glasses. Make your own polarized glasses. Understand synchronized glasses. 