Google Glass ancestors: 45 years of digital eyewear (photos)

Steve Mann is considered the father of digital eyewear and what he calls "mediated" reality. He is a professor in the department of electrical and computer engineering at the University of Toronto and an IEEE senior member, and also serves as chief scientist for the augmented reality startup, Meta.

Mann is wearing his wearing his EyeTap Digital Eye Glass from 1999. An EyeTap is worn in front of the eye, recording what is available to the eye and superimposing the view as digital imagery. It uses a beam splitter to send the same scene to both the eye and a camera, and is tethered to a computer worn to his body in a small pack.

MyVu's Personal Media Viewers hooked up to external video sources, such as an iPod, to provide the illusion of watching the content on a large screen from several feet away. From the collection of Dan Cui.

MyVu's ViSCOM digital eyewear from 2010. The company that developed the technology, MicroOptical, was founded in 1995 by Mark Spitzer, who is now the director of operations at Google X. From the collection of Dan Cui.

Unlike Google Glass, Meta's eyewear enters 3D space and uses your hands to interact with the virtual world. The Meta system includes stereoscopic 3D glasses and a 3D camera to track hand movements, similar to the portrayals of gestural control in movies like "Iron Man" and "Avatar." Meta expects to have more fashionable glasses in 2014.

Steve Mann believes that Google Glass can create eye strain. He wrote, "Google Glass and several similarly configured systems now in development suffer from another problem I learned about 30 years ago that arises from the basic asymmetry of their designs, in which the wearer views the display through only one eye. These systems all contain lenses that make the display appear to hover in space, farther away than it really is."