This isn't limited to glasses. I purchased a 12x12 sheet of solar filter film from a seller on Amazon, manufactured by Thousand Oaks Optical (who are listed on the American Astronomical Society's list of reputable vendors), and I'm also being refunded.
I checked the Thousand Oaks Optical site and they have a list of legitimate resellers of their products, and the Amazon seller I used is listed. I'm surprised Amazon didn't do the same basic checks before e-mailing me.
When I was searching for more information after receiving the e-mail, I also found someone on an astronomy forum[1] who is being refunded for a telescope that appears to retail for around $1199.
If it was "fulfilled by Amazon", it doesn't matter what seller you chose, you could have been sent a counterfeit item from another seller.
Sellers using fulfillment-by-Amazon send their stock to Amazon's warehouse, where it gets thrown in the same bin as all the other stock of that item from everyone else selling it. When it gets pulled to ship to you, there's no guarantee you get one that came from the authorized seller, versus a counterfeit someone else sent in with the same SKU.
Sellers can opt-out of commingling inventory at extra cost but most don't. Given you got a proactive refund, that seller probably has commingled inventory with everyone else, and Amazon is worried they sent you a fake that'll get someone injured and cause them liability.
That's what I would've expected too, but it seems not. Then again, if you still have eyes after this event you might see others filing class acts afterwards.
I've gotten counterfeit body wash (Shiseido Super Mild) and counterfeit microSD cards off Amazon, and, ironically, the only things I buy off amazon.com now are books, because if they're counterfeit, it'll be obvious, and it certainly won't cause me any harm.
Everything else I'd rather buy from the manufacturer (and pay the full, unsubsidised shipping cost -- not Amazon Prime) or a reputable distributor (digi-key/mouser for electronics, CS Hyde for films/tapes, etc). The prospect of having my eyes fried because of counterfeit PPE is kinda horrifying.
I checked the Thousand Oaks Optical site and they have a list of legitimate resellers of their products, and the Amazon seller I used is listed. I'm surprised Amazon didn't do the same basic checks before e-mailing me.
When I was searching for more information after receiving the e-mail, I also found someone on an astronomy forum[1] who is being refunded for a telescope that appears to retail for around $1199.
[1] https://www.cloudynights.com/topic/587658-amazon-eclipse-gla...