The best you can hope for is inoffensive! I bought some fairly plain black ones in sainsbury's for a tenner to use when I'm wearing my contact lenses. Mostly I wear my glasses (I'm short sighted) and peer out under or over them if I need to!
I can't wear off the peg as I have very bad eyesight, but I got a catalogue yesterday with a La Redoute order called Pia Jewellery. They have gorgeous reading glasses ( I would be buying some if I could!). They are 15 or 20 pounds each. The link is www.piajewellery.com. Be careful not to get sidetracked by the lovely jewellery and (rather expensive) bags.