https://www.digitalcameraworld.com/buying-guides/best-camera-glasses#section-best-4k-camera-glasses
https://youtu.be/Wr-_neqfirc
Maybe its a wire to a battery pack for glasses that are recording ?
Here's one - not sure of what glasses he was wearing unless someone has more of side view
https://www.zdnet.com/article/ces-2025-the-8-most-advanced-smart-glasses-we-tried-and-were-impressed-by/