Might be worth it for Juliets - mine are ten years old and have taken a lot of abuse - (particularly being hit by the boom of dinghies and falls while skiing/cycling). I think I'm on my fourth set of lenses!
Not OP, but I too loose sunglasses all the time. I'm pretty sure those are mine. Now as soon as I figure out what Juliets are and where "Yosemite backcountry" is, I'll prove it to you.
Actually, I've been able to hang onto my most recent pair for well over a year now. The trick is never taking them out of the car. The way they get lost is you wear them from your car into some house and take them off.
