Google Glass is a head-mounted wearable computer developed by Google[9] with the mission of producing a mass-market ubiquitous computer.[1] A uniqueness is the optical display, which is resting in the peripheral vision with being attached to a specially designed lightweight glasses frame. Therefore, the device is also being denoted as a Peripheral Head-Mounted Display (PHMD).[10] Contrary to popular literature, Google Glass is strictly speaking not a Head-up display (HUD) if following the original definition by NASA,[11] since (1) the perception of information is independent from the angle of the head position and (2) information can only be augmented indirectly with the help of a camera playback. In media-theoretical context this technology belongs to the non-immersive augmented reality.[12]Besides displaying information in a discrete smartphone-like hands-free format,[13] wearers are enabled to communicate with the Internet via natural language voice commands or tapping and sliding on the glasses frame.[14][15] 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,[16] for the same price.On January 15, 2015, Google announced that it would stop producing the Google Glass prototype but remained committed to the development of the product. According to Google, Project Glass was ready to "graduate" from Google Labs, the experimental phase of the project.[17]