How do you stop safety glasses from clouding over ?

[bitingmidge]

the only first aid required would have been a change of jocks. thats just my thought on it and i have no intention of running any kind of testing. :eek: :eek: :eek:

I had to do that and they didn't even make contact!

Cheers,

P

[Iain]

A few little pointers on optics from a friend of mine who manufactures sunglasses:
There are two plastics used in lenses, polycarbonate which is fairly soft and prone to scratching and CR (Columbia Resin) 39, CR39 is the better option but will cost more, it will scratch but not as easily as polycarb.
Distortion is caused by a couple of factors, one is uneven lens thickness and the other is a flat lens.
A good eyeglass has what is called a six base or eight base curve, that is essentially means that the lens is of even thickness and follows the curve of the eyeball so that there is an even spacing between lens and eye, or as near as practically possible for a mass produced off the shelf product.
As for sunglasses that cause nausea, sound like any one of a number of factors, cheap glasses (manufactured cheap like Oakley but big $$$ when they get here) do not adhere to the base curve and this combined with a tint that does not agree with you can cause the symptoms described, whilst it may be trendy to have a puke green lens, it can be hard on the eyes (read your eyes, not everyones) and cause problems.
Find a colour that suits you, I like grey for sunnies but I know some who prefer browns.
If the glasses are polarised just a little out of whack on one side can cause all sorts of visual effects like a ghost effect of what you are looking at.
All the sunnies I use are glass lenses, photochromic and polarised and (free plug coming up) are made by Lentech, also known as Oxygen or Spotters.
Not cheap but work.
I have seen Bolle safety glasses but do not know how well they work, their sunnies boast a 6 or 8 base curve but are only an acetate lens which are really soft, pity really because the optics themselves are quite good.
You may have to see an optician and get a set of safety glasses made, and don't lose or damage the bloody things.
Homily endeth.

[journeyman Mick]

Iain,
I've been using the Bolle safety sunglasses for about ten years now and can recommend them. I tend to use them as my day to day sunnies as well and while the lenses aren't as good as my expensive (polarised) sunnies they are way better than cheapies and a lot of the "expensive" ones (read brand name cheapies). The lenses do scratch up after a while, but then mine do cop a hammering. You can buy replacement lenses though, which is what I do whenever they get too scratched.

Mick