Smart glasses have been around for years, Meta are on at least their 3rd generation and there are loads of others.
As I understand it they have a built-in safeguard around covering the camera light (so they can't record if it is covered) although this can be hacked by people. I could record you on my phone with no light on though.
The current meta glasses work as open ear headphones, you can take calls / have messages read out, send texts hands free and they offer AI to do things like live translation, reading signs, identifying objects. At one point I'm sure they were advertising them as you could look in your fridge and ask it for suggestions for recipes you could make from what you had etc.
Other smart glasses have a built in "heads up display" so you could for example read your texts or have a map with directions visible on the inside of the glasses where only you could see it, rather than having to walk round looking at a phone screen.
They are useful tech for people with some disabilities or just people who want to have both hands free for certain tasks.
They are really not the covert cameras I would be concerned about. Although meta, like most companies isn't all that trustworthy where your data is concerned.