And how does that work with astigmatism?
If the law allows it, Opticians could offer a combination price for eyeglasses and the exam. You can still have your presciption and go somewhere else for glasses, but you are still paying that price. That they don’t do this is probably due to competitive pressure and/or the law.
Easy fix for that: “Free eyeglass adjustment with any purchase over $50”
If I were the optician I’d even say, “If you want to get your glasses online we’re okay with that. We will even professionally adjust them for free if you make any purchase over $50. So if you order your glasses onljne but come to us for cleaning supplies, lanyards, cases, clip-on sunglasses or other accessories, we will adjust them for you free of charge.”
The accessories are where lots of margin is anyway.