I've always wondered if cheapie sunglasses provided real UV protection and according to some articles on the Net, they do. But not sure how much that applies to ALL cheapie sunglasses.
So anyhow, is it possible to use our UV torches as a way to test if the glasses block out the light?
From what I read, UVA wavelength is 320-400nm and UVB 290-320nm. If my UV light is within that and I shine it at a sunglass that says 100% UV protection, will it not be able to shine through?
(Sorry if this is a dumb question, I'm a non-science guy)
I tried out one of those keychain UV lights on a few sunglasses (not sure what the wavelength is) and they shined through more on some then others, but it also seems that the darker the tint of the glasses, the less light passes through, which shouldn't be the way to measure its UV coating.
A clear lens with UV coat should be able to block out the light as well?
Would like to hear some opinions on this and whether there's any DIY way of testing sunglasses UV protection without having to go to an optician.