'All Meta Ray-Ban models have relatively thick plastic frames with a camera lens located in the frame's upper left corner (or upper right if you're facing the wearer). On the opposite corner is the LED light, which automatically turns on when the wearer is filming. It lights up when a photo is taken and pulses when recording a video.
To take a photo or record a video, the user presses the capture button on the right arm of the glasses (near the LED light). The user can also use voice commands: "Hey Meta, take a photo" or "Hey Meta, take a video."
Meta also produces glasses in partnership with Oakley. The HSTN model looks like a rounded version of the Ray-Ban frames, with the camera and LED in the same location. But the Vanguard model looks more like wraparound goggles than glasses, and its camera and LED are found in the center of the nose bridge.'
https://www.cnet.com/tech/mobile/how-to-identify-smart-glasses/
