Have you tried on some of the library-lady reading specs on the rack in Boots? Still about £15-20 but at least you'll be able to see if they work first. They go from "can't quite see bus numbers without squinting" to "frequently try to hail lorries". I can't have them cos I got a stigmata or whatever it's called. But if you haven't they're fine. They just won't be as precise as a prescription.