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I had to watch the video twice, here's the important piece of text:

"the curvature of each lens changes,"

"responding to input from an infrared distance meter build into the bridge of the frames"

So the glasses have to know your personal prescription. I know very little about optic, but one thing I've been wondering for a long time is why can't there be a camera pointed to your eyes that adjust the lens until the image on your eye is in focus?

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I had an eye test recently (in the UK, if it's relevant), and they had a device which seemed to do that. You sit down, look into the device and see a blurry image, which sort of "snaps" into focus as it works out the shape of your eyes.

That device was a fairly big thing linked to a desktop, though - no idea if it could be miniaturised or not. In addition, they followed it up with more "traditional" tests, which in my case disagreed with the results from that device. So maybe it's not quite there yet?

that already exists, it's the machine at the optometrist with the picture in it, usually of a farm or road for some reason. I imagine that technology is too bulky and too expensive as is to put in reasonable glasses.

https://en.wikipedia.org/wiki/Autorefractor

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