Many people fell compelled to keep parrotting the same bullshit about "the cheaper labor is the reason all this Chinese stuff cost less". What a huge crock of shit. I gotta wonder if that's all the more complex their reasoning skills are.
Optometrists couldn't make a living in the US if they charged what their services are actually worth and the customers didn't pay insurance for eyeglass coverage.. so play the "stick it to the insurance company" game to be a good consumer. The mall locations or office suites, the various employees that basically do very little, the expensive optical equipment and general overhead expenses/taxes wouldn't allow them to make a profit if they weren't selling $40 eyeglasses for $350 or more.
What the Chinese sellers aren't paying for, is what makes their businesses profitable.. no TV commercials, hundreds of flashy magazine ads, mall locations or custom suites and brand-name recognition are a few of the reasons. The Chinese are proving what eyeglasses really are.. wire and plastic/glass lenses.
Looking at inexpensive reading glasses (about $8US) you may see the spring-tensioned hinges and adequate fabricating techniques.. the only difference is the grind of the lenses, excluding all the add-on stuff that make doctor-selected glasses more profitable.
The lenses and frames are very likely CNC machine made.. so after the machines are set up/fed with material, the actual assembly and packaging time for a pair of glasses may be 10 minutes.. probably less.
The domestic assembly labs are very likey getting frames and lens blanks from the same Chinese plants, although probably thru different distributors who apply a brand name to the the frames and place them in fancier boxes.
Somewhere in the supply chain, someone is claiming that their components are better quality because they're being made to their exact specifications.
Unless there are some legal/trade restrictions for optometrists, they could just be faxing the prescriptions and specific eyeglass features to a Chinese factory, and receiving the finished product in a few days.