I have had mine for about a year now,they are very comfortable and being that my eyes are very sensitive to bright sunlight,these offer ultimate protection as well as ballistic protection for my eyes. I won my SG-1's at a military school so I didn't have to pay the price so I guess I'm really happy with my
Official Issue - Good Value
These glasses are issued to flight-line personnel in the AOR, and seem to work well. I don't know a lot of people who swap the lenses around, but they do keep the sand out of your eyes, and seem to be pretty durable for daily wear.
Only disadvantage- The rubber foam around the eye pieces encourage sweat in hot enviroments. It's a trade off for the sand protection.
I ordered a pair and after about two to three times of changing between goggles to sunglasses they broke where they snap together at the hinges. So I sent them back as defective and US Cav quickly sent a replacement, and the same thing happened, they broke when I tried to use the elastic band for the goggles. So for $100 they are not worth the trouble and cheaply made.