That's funny - all I've used for the last 15 years is polycarbonate, and they last me 2 or more seasons without scratching. Besides, they are shatterproof, and the glass is often what does the damage to the eye - not the object. I am not making this up, my brother is an eye surgeon.
And the reason my polycarbonates don't get scratched or lost.... (drum roll)... CROAKIES!
Actually I use the thinner 'cats' that REI sells.
Newbiefish I noticed you mentioned sunglasses as something to put in your vest... I can hear the scratching from here. Ryan - no croakies, getting dark... put them in a pocket... SCRATCH CITY. Put them on the dashboard to drive - S.C.
I wear the sling religiously, but it has nothing to do with style... it just plain makes your shades last longer. When it's dark you just hang them on the rear view mirror. Man do those shades last a long time that way!
BTW - I have been wearing the $49 Fishermen's Eyewear wraparound Polarized Polycarb shades going on my third season. Prior to that I wore the Bolle fishermen's shades but they discontinued the ones I liked. No noticeable scratches, thanks to the neck sling. With all the money I saved I think I am going to upgrade to some swanky Action Optics shades, and you can bet they will be polycarbonate and worn on a sling!
Downsides to the sling method: You will always have a few crumbs on them after you eat :hehe:
Seriously, never wipe with paper - only soft cloth. When fishing, I use my tee shirt after dampening the lenses.