So you want to go see the latest blockbuster with in-your-face 3D effects...but your significant other doesn't share your enthusiasm. In fact, many people find that 3D movies causes nausea and headaches. What to do? Leave them at home? See 2D instead? Nonsense! Those aren't solutions. Instead, build a pair of Anti-3D glasses for them!

Step 1: Materials

2 pairs of Polarized 3D glasses.
(Mine were "Master Image" by far the easiest ones to work with)

Small flathead screwdriver

Razor blade/Scissors

Step 2: How Passive 3D Works

Most of the theaters these day are using "Passive 3D" technology. The glasses have radially polarized lens, one clockwise, one counter-clockwise. The image on the screen is projected through two polarized lenses, again, one clockwise, one counter-clockwise. The glasses allow the light from only one projector to reach each eye, therefore each eye sees a slightly different picture creating the 3D effect.

To see this in action, put a pair of 3D glasses on and hold another pair facing you. Close one eye and slowly turn the pair of glasses you are holding. You'll see one lens turn almost completely dark. Switch eyes and the other lens will be dark. Our Anti-3D glasses will be modified so that each eye receives the same image.

Step 3: Disassemble the Glasses

Insert the screwdriver and carefully pop off the arms.
Using the screwdriver carefully pop off the lens retainer piece.
Be sure to leave the lenses where they are. You don't want to mix them up!
Repeat on second pair.

Step 4: Swap and Trim Lenses

Exchange the two lenses as shown in the photo. Due to how the lenses are made, we have to keep them facing the same direction as they originally were in the glasses. Using the retainer piece as a template, trim the edge of the lens off so it will fit into the frame.

Step 5: Reassemble

Snap the retainer piece and arms back on, and you're done! There will be a small gap at the inside corner of the lens that was trimmed. It's far enough in the corner that it shouldn't effect your viewing, but if it does you can cover it with a small piece of electrical tape.
Now hit the theater and enjoy the glorious flatness of 2D!

Step 6: RealD Brand Glasses

The Real D brand of glasses are becoming much more popular these days so you might not be able to find the Master Image ones that I used. You can still follow the same procedure on Real D glasses, but it will be a bit more complicated as you will have to carefully snap apart a glued seam, and then re-glue it upon assembly.