would you buy your glasses on line?

I found glassesdirect.co.uk which is a brilliant idea, really great but I wonder: will it pick up? can it work? how many glasses go lost or disappear? surly it must be economically viable, but how? anyway kudos for the creators of this online shop.. I might give it a try. or not? if it was just for a pair of shades, no prescription lenses, then I would do it without any problem. But what about the prescription? I like the idea of being there with all those machines to check the glasses. or maybe this is because it’s the only way i know..