Is that true? I've ordered all of my glasses online for the past few years, and they've never asked for anything other than a form to fill out.
Many shops won’t sell you glasses unless your prescription is under 1 year old. This allows them to charge you for an exam when you don’t necessarily need it.
Probably not quite as good as a live view, but not bad.
And I find sites like Zenni are so cheap that it's worth taking the risk: an ugly pair can go in the car /gym bag / work desk for if I lose a contact lens.