I bought some Oakley Prescription sunglasses last year... not the Oakley normal glasses frames with some tinted lenses, but Oakley shades with the officical Oakley prescription lenses which have to be made by them directly.
The design I bought (Half Jacket) has clip-in lenses, so I bought the frames with standard (non-script) lenses and then had some scripted lenses made. This way I have them in my car for day-to-day with the script lenses in and if I want to wear contacts I pop in the standard lenses.
They were VERY expensive, but this is up there as one of the best things I have ever spent my money on and I would buy them again in a heartbeat.
Half Jacket
Incidentally I work with a guy who trained and worked as a dispensing optician many years ago (he's a programmer now
) and spoke to him at length about all of this before I made my choices. The main problem with the majority of prescription sunglasses you get is that they are not tinted glass/plastic - they're normal glass/plastic lenses with a tint applied to them, which is OK for most situations, but start putting anti-glare, and anti-scratch on as well and that's 3 coats, not ideal. The best solution is lenses made directly by a manufacturer as they will use proper coloured plastic rather than an applied tint, but that's where it starts getting expensive.
In the end it depends what you want from them and how much you want to spend, my Oakleys weigh nothing (a pen drive is heavier), work equally well rock climbing, hiking, or driving to work, and will serve me well for many years.
Oh and I bought them from the company featured in the offer in Current Bargains, pretty cheap to start with, and the service was excellent !