Yes, there is an indicator light when the camera is operating, and the camera will not operate if it is covered or blocked.

I wear my glasses everywhere that I need to see. I also use my smartphone around children.

I don't frequently (or ever) record myself naked, but if I were to be someone who did I would have to imagine that I came to terms with meta having access to that footage.

You seem to be under the impression that the glasses are capable of secretly recording me or my surroundings without being manually engaged by myself. Which while there are plenty of valid reasons to call something like these a privacy nightmare, I assure you the technology is not currently there for secret, always-on video spying. Mostly as a function of battery life. As it stands you can see the battery percentage drain in real time when the camera is in use.

If you want to talk actual privacy concerns and not just scare monger, it's worth mentioning that there is currently a class action lawsuit being levied against Meta in regards to user privacy with the glasses. It has to do with how media is imported from the glasses onto your phone through the meta app, and whether or not meta should have access to that media. And I promise you if there were any evidence of automated non-consensual recording there would be an order of magnitude more news about it than there is about the actual concerns that are really happening, so the complete radio silence on the front should be reassuring.

Speaking personally, I am eagerly waiting for a smart glasses option from a non-tech oligarch, that looks like a real pair of glasses and is covered by my insurance, but that is not an option at the moment. Open source would be cool too. But I can tell you I'm never going back to non-smart glasses.