- Over 40 years of research in augmented reality (AR) has been conducted, starting with Ivan Sutherland's head-mounted three-dimensional display in 1968. - More recently, mobile AR research at Columbia University from 1996-2001 developed systems for campus tours, historical hypermedia, and restaurant guides. - Current issues with mobile AR include inaccurate tracking from GPS and sensors, small display field of views, and handheld form factors. Improved sensors and eyewear interfaces may help address these issues.