A mirror with a camera in it, in front of which you can try on your new glasses in the optician. The video from the camera is shown (horizontally flipped to mimic the mirror) on a screen next to the mirror with a 20s delay so you can look at your blurry face in the mirror then take off the frames you're trying out and put on your normal glasses to see what you actually look like on the screen.-- hippo, Oct 17 2023 Its video now, no mirrors. https://www.warbypa...dbaadf8d5b4d442c82cTry on thousands and thousands of frames [minoradjustments, Oct 17 2023] [hippo] How interesting personal preferences occur. I just saw a virtual reality app that lets you look at how elegantly a toilet can dress up your very own bathroom. No 20 second lag. No kidding.-- minoradjustments, Oct 17 2023 I remember a science fiction short story where windows were made of time glass, so that when you looked at the window you saw what was happening on the other side a year or more ago.-- pocmloc, Oct 17 2023 Addendum: Opticians' shops often have a lot of mirrors in them. With this invention, opticians have to be very careful about the placement of mirrors to avoid the camera being able to see the screen in a mirror because of the video feedback this would cause. The problem here is legal: If you went into the shop to try on some new glasses, the video of you trying them on could be fed back through the screen reflected in the mirror and then, after a 20s delay, the screen again, such that weeks later a ghostly, corrupted copy of your face was still there. Technically this counts as personal data and use of your personal data without consent, with all sorts of GDPR and other issues.-- hippo, Oct 17 2023 Great story. Legal authorities witnessing the view out a slow glass window that shows a year-old crime as if it were happening now. Whats next? 2-way slow glass? Boing.-- minoradjustments, Oct 17 2023 random, halfbakery