The article doesn't explain how they've been able to keep the "affordable glass" competition out of the market though. Natural monopolies are quite rare. My intuition is that this is not a free market and there is some degree of regulatory capture. I'm guessing not just anyone can set up shop and start manufacturing/selling cheap prescription glasses? Can you import them easily?
As far as frames go, Luxxotica exists because of regular old market-consolidation forces (i.e. it owns so many brands that it makes deals with optical stores to be their only supplier of frames.) Same reason you'll see restaurants that only sell soft drinks made by PepsiCo.
But the real interesting puzzle is why there are so few lens manufacturers.
If you Google the names of these (Zeiss, Leica, Olympus, Corning, etc.), you'll likely quickly figure out that 1. there's about one major optical glass producer per country; and 2. all the ones you'll ever hear about in an Western prescription-glass context are headquartered in countries that are key NATO players; and in fact often in the capitols of those countries.
What's up with that?
"Optical glass", besides being in prescription glasses and smartphone cameras, is the key bottleneck in the resolving power of military imaging satellites.
Each one of these companies is an example of the opposite of "regulatory capture" — these companies exist at the behest of the state, as pseudo-nationalized entities. They're essentially defense contractors that happen to make civilian products on the side.
Competitors to these companies aren't allowed to spring up, because any such a competitor would essentially be a mercenary arms-dealer for IMINT materiel assets.
With exactly one high-quality optical-glass company per country, each under said state's thumb, states can easily track where everything (of sufficient resolving power) that that optical-glass company makes, goes.
It's basically the same reason that there's only a few companies in the world making highly-precise gyroscopes (that could be used for missile guidance); or making industrial-grade cycling centrifuges (that could be used for uranium enrichment.) States will not permit these to be manufactured "out of sight."
In the US at least, EssilorLuxottica owns a large portion of the eye glass shops (Target Optical, Lenscrafters, etc) and eyeMed insurance. VSP another eye insurance company has a similar set up where they own their own glasses maker.
There's nothing really stopping anyone from buying from discount eye glass companies online, but you have to guess at which frames you'll like based on pictures and reviews instead of instore.
