I just get prescription sunglasses at costco - they end up something like $100 or so. Probably less coverage than sport sunglasses, and I've actually got a set of those with interchangeable lenses that are in the bottom of my camelbak if I need them.

I've never gotten contacts since I work in a lab, and I'm really bad at personal maintenance type stuff beyond showering and brushing my teeth. And because I only wear my glasses if I need to see far away - driving, biking, kayaking, and watching powerpoint presentations. Otherwise, I just find them annoying.

The spare pair of normal glasses in my biking pack works reasonably well, and I've got another old pair of glasses that I keep in my kayak.