Privacy

They'd better not, for the safety of wearers. I can't be the only one who remembers the way that people wearing the Google Glasses:

Google started selling a prototype of Google Glass to qualified "Glass Explorers" in the US on April 15, 2013, for a limited period for $1,500, before it became available to the public on May 15, 2014. It has an integrated 5 megapixel still/720p video camera. The headset received a great deal of criticism amid concerns that its use could violate existing privacy laws.

On January 15, 2015, Google announced that it would stop producing the Google Glass prototype.

The incident where an entire pub harangued and ejected someone for wearing a pair is a standout. People generally don't want their private or public interactions and likenesses recorded or livesteamed by someone wearing a camera on their face, even though it's less obtrusive than someone walking about with a camcorder pointing it at everyone/thing they see.