Just a reminder about Panoptx, they will replace them if they break. I have only seen two pair that actually broke; I've seen lenses get screwed up when they were cleaned improperly (on the inside where the anti-fog coating is). My main complaint is the foam "gasket" that seals out the air. It gets old and distorted after a while. They must be sent to Panoptx for lens or foam replacement.
The Wiley-X SG-1 that Fred mentioned is flexible and I would be very surprised to see one of those break. The seal will not absorb moisture and peripheral vision is very good. The price is reasonable at MSRP (not to mention my forum discount of 20% on Wiley-X) and parts (lenses are very cheap, when they need replacing) are easily obtainable.
I sell both brands and have worn both -- right now I'm like my SG-1's.
If you want a pair, this is the contact info:
Dr. B. E. Popham
12 Nelson Street
P O Box 295
Cartersville, GA 30120