In 1995, a company called i-O Display Systems released the i-glasses! (the "!" is part of the name)
Nearly 20 years before Google Glass and the Oculus Rift were released to developers, i-glasses were on the market. The company described the product as a "unique light weight head mounted personal display system that creates a big screen television illusion."
They debuted for about $800:
Some versions had head-tracking, like the Oculus Rift. Later versions included batteries and a basic video playback mechanism, like a sort of proto-Google-Glass.
This is how they were advertised:
They were marketed first as gaming devices: cheaper versions connected to game systems and PCs as straightforward wearable displays, while premium versions could be used to control games. It was supposed to be the "ultimate personal display product for the virtual reality and portable computing market," whatever that means.
This is how they actually worked:
The i-glasses won all the soft accolades devices like this normally do: the best-of magazine awards, the vague design organization honors. Due to price and limited utility, though, they never quite took off.
A press release from two years after the glasses first came out acknowledges a change in direction: "i-glasses! have been successful as a virtual reality product. i-glasses! were an even greater success at creating new applications and markets for personal display systems." It makes the bizarre and extraordinary (but possiblly true!) claim that "20,000 dentists are letting patients enjoy i-glasses! during tedious dental procedures," and touts the glasses as a "sales presentation system."
Ultimately, though, the concept was too little, too soon. It may be the case that, even all these years later, Oculus and Google Glass are too.
You can watch a full collection of old promotional materials here: