There's a pretty bright light that turns on when the camera is recording, and if you try and cover the light the camera won't work. Their existing glasses are pretty popular and there haven't been big compaints about it. If you really wanted to do secret recordings there are plenty of better and cheaper glasses in the market for it.

There are several videos showing you can easily cover or disable the LED with no loss in functionality.

What a relief, they really thought about it, exactly like the AirTags with the warning buzzer.