Facebook's Smart Glasses will be available in 2021, the company's head of hardware said. However, the wearable will not support mixed reality features like the rumored Apple Glasses.

In an interview with Bloomberg, Facebook's head of hardware Andrew Bosworth said the glasses will appear "sooner rather than later" but will not offer AR technology that superimposes digital images on real-world environments.

"These are certainly connected glasses, and they certainly offer a lot of functionality, (but) we're pretty secretive about exactly which functionality they offer," Bosworth told Bloomberg. 'We just call them smart glasses.'

Facebook announced the creation of smart glasses in partnership with sunglasses brand Ray-Ban at its Oculus Connect event in September, when it unveiled its new Oculus Quest 2 virtual reality headset. At the time, Bosworth called the project "the first truly fashionable smart glasses."

The current prototype features a Wayfarer-like design with thick frames and dual cameras placed next to both lenses.

While this design is not official, Facebook's smart glasses appear to perform more like Snapchat glasses, which are more accepted as novelty items than practical, everyday lenses. Nevertheless, Facebook's platform has a strong presence in the photo and memory capture community, including in the portal smart display sector.

Indeed, Bosworth highlighted to Bloomberg a scenario for Facebook's Smart Glass application: parents documenting moments in their children's lives.

"By the time you start up your phone, not only have you probably missed it, but if you haven't, you're probably watching the actual event through your phone," he said.

Facebook is one of several companies aiming to launch everyday smart glasses, and if it does, it could be the first of the major companies to bring them to market. Google has also filed a patent for smart glasses. Of course, there is already excitement about Apple Glass, which Bloomberg previously reported will be available "as early as" 2023.