Simple Variable Brightness Lens Using 3d Glasses

Here's a simple lens that will adjust the amount of light that passes through when you turn it, it is more of a proof of concept that anything else, made from a cut off glue stick, and the both the lenses from a pair of 3d glasses.
I am not sure exactly how it works, but when you flip one lens around, then put it in front of the other one, it blocks out light depending on how much you rotate it.

Hopefully, someone with skill and patience will see this idea and make a set of steampunk goggles!