As with many things, you get what you pay for re: Opatra et al.
All peer-reviewed studies I can find for light therapy only look at medical-grade equipment, not home-use devices.
Which is an important distinction.
After all, as someone else in this thread said, not all LEDs are the same. Studies looking at such devices use LEDs which are UV-free, function at specific wavelengths (and have enough power to, so aren't USB charged), and usually involved specific, even coverage... A plastic handle with 5 weak LEDS on the end the Selly Telly lady tells you to jab your jowls with while you watch Corrie probably isn't going to offer comparable results to the "scientifically proven study".
Has Opatra even published a non-peer, clinical study? I'm yet to come across one…
I do see they like to sell with "FDA cleared" or "FDA approved" in their descriptions, but that's marketing that implies more than it means. The FDA don't do their own testing (not for electronics, they're thankfully more involved with medicines). They just require a company to submit a clinical study (which a company is free to do themselves and doesn't have to be independently reviewed). Or if their product is similar enough to one already cleared/approved by the FDA, it can pass through automatically.
A quick search for "FDA recalls" reveals a few flaws with that process!
Similarly Opatra seem to make a big deal about "sold at Harrods" as if that means something too.
A quick search of UK business forums turns up lots of tips when pitching to Harrods' buyers, the main one being that agreeing to sell to them at cost or a small loss (!) is actually a win-win, with the benefits to future sales elsewhere (and other retailers agreeing to stock it) making up for any lost profit from sales made in Harrods.
A consumer hears a product is "sold in Harrods" and they think "it must be quality", regardless of whether it's true!
If I were to buy an LED light therapy device I'd lean towards a company with a background in producing medical equipment, like Omnilux. They've branched out in to home-use devices like masks, publish their studies, and sell their masks with the assurance they use "medical-grade LEDs" — which given they make and sell medical-grade equipment as their main business, I'm more likely to believe.
So yeah: like selly telly watches, there's the real deal, and there's the pretence of the real deal …picked-out-of-a-catalog Chinese device and a logo slapped on it, an RRP inflated, and lots of oohing and ahhing involved.
Not a direct comparison, Opatra - don't worry.
It's certainly interesting that neither the beauty press (e.g Vogue, Cosmopolitan) or consumer press (e.g., Good Housekeeping Institute) feature Opatra devices in their lists of the best LED therapy masks, etc.