Thanks for your thoughtful comment. I, myself, do know how to measure the distance between my pupils, align and adjust frames, replace screws and nose pads, and also measure and mark lenses with pupil and bifocal height, am aware of matters of curve and tilt--most of this I learned by reading instructions from online opticians. As to verifying prescriptions, and whether centers are properly set, I have recourse to the optometrist and ophthalmologist. I do not insist that everyone should use internet opticians, nor that there are not deficiencies and problems apt to arise if you get your eyewear this way. But for the average prescription, their work compares well with that from the mall store--and many customers of these chains have stories to tell of wildly inaccurate prescriptions, and being advised by clerks, not professionals, to ""wear it for a week or two -- you'll get used to it."" (With the exception of new wearers of progressive lenses, there should be no period of acclimatization necessary if the lenses are made correctly). And if Global Eyeglasses (using overseas labor with lower labor costs) can provide a good quality frame with brand-name progressive, photochromic CR-39 lenses, AR, UV and scratch-resistant coating for about $100, does the overhead of a brick-and-mortar optical shop really justify a price of $600 for something of the same quality? I am taking a wild guess that Global's cost would not exceed $50 for these glasses. Let's say the shop in the mall's all-in cost including overhead is $100--they buy the lenses and frames from the same source as Global does. (Both estimates are probably high). I'd think $200 might be a fair retail price. $600 strikes me as a monopolistic rip-off. I think there's a niche for a kind of square-deal optical shop, which would charge less than, ""what the traffic will bear,"" and offer the one important feature the onliners can't adequately provide--the ability to try on frames, and receive personal advice and guidance from trained personnel. There are a few stateside opticians who offer service like this, at fair prices, notably Eyeglass Lens Direct, and Replace-a-Lens, and guess what--they are online opticians too!