Hi guys,

In this article I'll show you how I made these polarisable and flexible glasses out of two old pairs of 3D glasses.

WARNING: do not use these glasses as sunglasses, they do not protect your eyes as real sunglasses do (especially from UVs).

ABOUT THE PROJECT:

Why? I recently found a video about sunglasses that can change the light filtering when you rotate the lenses. As I knew that 2 pairs of 3D glasses rotating in front of each other behave similarly, I decided to give it a try.
How much time? Maximum 2 hours if you already have all the stuff needed and if you follow the steps.
How much money? If you make it out of old stuffs like I did, it is free. However if you want to buy the material, it would cost approximately between 5 and 10 euros maximum.
What use? As said above, they are not sunglasses but rather funglasses, for example as costume accessory. It might be an interesting project to do with kids.
How it works? These glasses use the polarization capacities of the 3D glasses lenses, to let or stop the light to pass through. Actually the name polarisable is not true because the glasses are always polarized, but playing with the rotation of the lenses allow to control the light transmission through the glasses.
To go further: I would love to do this with a 3D printer, but unfortunately I have no access to any 3D printer. Wood glasses with such lenses would also be interesting.

Step 1: Materials & Tools

The material is quite basic:

2 pairs of 3D glasses. I used this glasses because they where damaged, with some scratches on the lenses and I have better pairs of 3D glasses to see 3D movies.
Some sheets of "rubber craft" (that's the official name but I would rather call them "foam sheets" as the official french name is "mousse").
Some metalic parts that can bend (like a can, or a metalic wire)
Glue (I used a cyanoacrylate glue)

And the tools:

A pen, some sheets of paper, a ruler
A pair of scissors

Step 2: The Design

To start, I just draw on a paper how I wanted my glasses to look like. I based the design on my actual sunglasses to have correct proportions.

The disk shape of the lenses is important because 2 lenses are rotating in front of each other to have the expected effect. And the best shape for this is a disk.

Step 3: Cutting

When you have found the best shape for the glasses, draw it on the rubber craft sheet and cut it!

The frame of the glasses is made of 3 layers:

The front layer (the one you draw)
The back layer (similar to the front layer)
And a layer in between, with thinner edges, and no top (see the photos).

All these layers glued together are going to hold the rotating lenses.

Then cut the frame of the rotating lenses: 2 rings that fit in the middle layer of the frame, and with holes with the same size of the front and back layers.

To finish, cut the arms. I double the layers so they are thicker, and I made it in a blue rubber craft.

Step 4: Glue Part 1 (the Lenses)

At first check how 2 lenses behave on top of each other.

WARNING: Depending on the the face and the position of the lenses, the effect will not be the same! For example, with 2 lenses you have all these possibilities that can lead to different effects:

Lens 1 on top face up, lens 2 below face up
Lens 1 on top face down, lens 2 below face up
Lens 1 on top face up, lens 2 below face down
Lens 1 on top face down, lens 2 below face down

But also:

Lens 2 on top face up, lens 1 below face up
Lens 2 on top face down, lens 1 below face up
Lens 2 on top face up, lens 1 below face down
Lens 2 on top face down, lens 1 below face down

It is a lot of possibilities, so make sure you find the best one. The best one correspond to both lenses letting the light pass through, then stopping all the light when you rotate one of 90°. When it is okay, you can glue one lens of each couple of lenses to the front layer of the frame (keeping in mind that the position and orientation is important!!).

Glue the middle layer to the front layer.

Glue the 2nd lenses of the couples of lenses to the rings (still keep in mind the position and orientation you choose!).

Step 5: Glue Part 2 (the Arms of the Glasses)

As I wanted to be able to change the arms position, I have added 2 tiny parts of metal (easy to bend, but also strong enough) between the frame and the arms.

WARNING: be careful when you cut the metallic parts, or when you glue it on the glasses, you don't want a piece of metal to hurt your eyes when using the glasses!

I glued the metallic pieces where I wanted the arms of the glasses to be, then I cut the back layer of the frame just where the metallic parts stand.

To finish I glued the arms on the frame (a tiny part is glued on the metallic parts).

Step 6: The End & Conclusion

Bend the arms, add the 2nd lenses in the slit of the frame, and the glasses are ready!!

Now when you rotate the lenses, the glasses get darker or more transparent depending on the angle.

Conclusion:

As a conclusion, it was a funny, quick and easy project! To go further, it would be interesting to make these glasses with a 3D printer or with wood, and why not use a UV filter so they could be used as real sunglasses!

To finish, the only problem I had with the finished glasses, is that the lenses do not rotate smoothly because of the rubber craft texture, but that is a minor problem.

I hope you liked the project, let me know what you think about it!