Another reply mentioned Snaps, which I haven't heard of. It looks interesting, but ultimately it has the same flaw. I'm not going to wear dark sunglasses with LEDs indoors to take family photos.
I suppose there really is no ideal solution. It's either going to be noticeable and thus culturally acceptable or hidden and be bashed for being used by creeps. I suppose a device like Google Clips is probably a better solution for my needs, but it lacks that killer "wink to take a photo" feature.