You know, for all intents and purposes I keep a couple packs of disposable contact lenses on hand for shoot trips. I too am bespectacled (terribly nearsighted, terribly). For most everyday purposes I wear the glasses, and if I go to the range I put in the contacts and then just wear my safety glasses. Though they're "disposable", so long as you put them into solution they are reusable to a certain extent, I've gotten close to two weeks out of a single pair before. You can get a 30 day supply for like 30-40 bucks. You will have to see your doc to get fitted for lenses and get your prescription written down--contact prescriptions are different from spectacle prescriptions.
Though honestly, I'm going to talk to the ol' doc about getting prescription ballistic multi-coated and fog-proof lenses put into a pair of larger, safety type frames. Probably cost around 250 or so, but it'd be worth it.