Give it about a year and a half, and everyone who said "I'd never wear smart glasses, that's a stupid idea" will be ready to plunk down the money for that shit, when they can literally put live subtitles in your field of vision, 100 percent perfectly, in real time, guaranteed.
Shit will be like the universal translator, in Star Trek. People won't even bother trying to learn each other's languages, anymore. Motherfuckers will be married for fifteen years, and literally just talk to each other with their translator glasses on, the whole time. Then if there's an extended power and internet outage, they'll be like "oh, shit...without the live subtitles, all we're gonna be able to do is dirty sex talk and asking each other where the bathroom is."
Shit, that'll mean even more extra babies conceived during blackouts than usual.
They never took off because they marketed it poorly. Just partner up with Dragonball Z and make them look like scouters and they'll sell out immediately.