No such thing as glasses that can't be lost or broken, so consider that when budgeting. Oakleys and Revos are probably the most expensive and are both certainly nice.

Since you're anticipating varied conditions you might consider interchangeable lenses--with very dark for sunny snow travel and lighter ones for cold and fog.

Plastic or glass lenses, polarized, photochromatic, plastic/metal frames, wraparound...the choices are endless. And yes, losing them is a pain--I've done that myself, as well as broken them and had screws vanish.

As a result, I always buy them on sale so it's not as painful when they're gone.

Cheers,