shops are causing us to lose business. I countered that they do not based on our internal research (we hired an independent firm to research it for us). We just don't have many patients who shop for glasses online.

And I stand by my assertion that Zenni and other online retailers' products are of low quality. They are, and there is no disputing it. Also, the original poster asked specifically about progressive lenses, to which I responded that buying progressive lenses online is a mistake. The reason is because a progressive lens wearer needs to have precise measurements taken with the frame on the face, which you can only do in person. In addition, the progressive lenses Zenni and other online retailers are old designs they can buy on the cheap. Furthermore, you really need to speak to a certified optician about available progressive lens designs that are suitable for your vision needs. There is no "one size fits all" progressive lens.