I was thinking about this today and I just don't get any problems despite lots of long full sunny days spent at 8 and 9,000 feet. If you're in Colorado you may be higher but I think the snow reflection is more the problem. I wear smiths with the Gold light 55 I think. That means they block 55 % visible light which is still pretty bright. I like them because they are bright enough that I still see fine if it clouds and light goes flat or in the shadows. Any lens HAS to block 100% UVA and UVB rays. Quality eyewear pretty much all does.
The worst thing you can do is wear a dark lens that doesn't block all of the A and B rays. The dark causes your pupils to dilate since they react to visible light and that lets even more of the bad stuff in. I wear the glasses as much as I can (most of the time) and they're pretty close to my face but I can still see bright around the outside of them. Don't think that really gets right into my eye though. I find shooting with glasses on hard but propping them on your head to shoot quick is easier then dealing with goggles I think.
Don't mess around in the mountains and on snow. Good eyewear is critical and worth the investment.
It's not so much the model year, it's the high mileage or meterage to keep the youth of Canada happy
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