UV protection

My sunglasses say “maximum UV pretection”. Does that mean anything, or is it like “all-natural ingredients”, meaning just about nothing? Does it refer to UVA or UVB? (Is that important?) And Is there any way to tell what UV protection my shades give?

Cecil may have covered this, but the on-line search turned up nothing.

Thanks,
Mike

Maximum UV protection would be to paint your sunglasses black so no light of any kind gets through :). I suspect that what they mean is something like “Our sunglasses offer the highest level of UV filtration available today.” I’ll let someone like PapaBear explain the difference between UVA and UVB. As for knowing what kind of protection your shades give, your best bet is if they tell you on the tag. I suppose that you could set up some kind of standardized experiment where you measured how much UV light was filtered out by your sunglasses, but that would be alot of trouble, unless you have a UV source and UV meter conveniently at hand. I don’t know if there’s any kind of consensus as to what level of filtration is necessary, so even if you did this experiment, it might not be very useful.


“I had a feeling that in Hell there would be mushrooms.” -The Secret of Monkey Island

So, (back to the top)
Papa bear or anyone? Do you know what “Maximum UV protection” really means?

Hmmm. what if you take some SPF30 sunscreen and put it on your glasses? Doesn’t that have the same effect?

Glass sunglasses should screen out uv, plastic maybe not, such as kids’ glasses. The point is, if you are going to wear sunglasses, which may actually make your eyes dilate a bit, you should not let the normal amount of uv in. This all relates to cataracts.

Some links, I’m not going to put codes.
http://www.healthtouch.com/level1/leaflets/aoa/aoa034.htm

http://www.aao.org/public/faqs/sunglasses_faq.html

When shopping for prescription eyeglasses, consider having the lenses treated with a UV protective coating. Or, select a lens material that inherently provides 100 percent UV protection.
Polycarbonate, the strongest lens material available today, offers complete UV protection. Because of its strength, the material is recommended for the eyewear of children and anyone who does anything athletic.

That from:
http://sola.hdg.com/professional/techtips/tip57.html

So polycarbonate eyeglasses should also give UV protection according to that.