|
You can check thes glasses to see if they are polarized with 2 pairs. Polarization cancells light waves in one plane. So if you hold one pair in front of the other and rotate one of the pairs 90 degrees, you should not be able to see anything through the glasses. If they say "polarized", and that trick does not work, don't buy them.
I also buy the cheap throw aways. I have ruined too many good pairs.
|