Source: NYTimes, Feb 2012
… later this year, Google is expected to start selling eyeglasses that will project information, entertainment and, this being a Google product, advertisements onto the lenses. The glasses are not being designed to be worn constantly — although Google engineers expect some users will wear them a lot — but will be more like smartphones, used when needed, with the lenses serving as a kind of see-through computer monitor.
Several people who have seen the glasses, but who are not allowed to speak publicly about them, said that the location information was a major feature of the glasses. Through the built-in camera on the glasses, Google will be able to stream images to its rack computers and return augmented reality information to the person wearing them. For instance, a person looking at a landmark could see detailed historical information and comments about it left by friends. If facial recognition software becomes accurate enough, the glasses could remind a wearer of when and how he met the vaguely familiar person standing in front of him at a party. They might also be used for virtual reality games that use the real world as the playground.