Question

A salesperson at a bargain counter claims that a certain pair of sunglasses has Polaroid filters; you suspect that the glasses are just tinted plastic. How could you find out for sure?

Short answer

We find out by looking through glasses as Polaroid glasses show clearer images than tinted glass.

Step-by-step solution

Polarised glass uses

Polarized glasses reduce the glare of light around you, whether it is coming directly from the sun, from the water or even snow.

Distinguish between polaroid glass and tinted plastic

If you look at the window far away with ordinary glasses no matter how you position yourself you will mostly see reflected polarised sunlight while if you look through polaroid filters, you will at certain angles see clearly through the window because the polarised sunlight will be filtered out. Generally, the object will be clearer (there will be less glare) with polaroid glasses then with ordinary tinted glass.

Hence, we find for sure what is Polaroid filter sunglass and what is tinted plastic sunglass.