An automated calibration method, designed for optical microscopes, may find a home in head mounted display units and heads-up augmented reality systems. "Ever since the development of the first applications in image-guided therapy (IGT), the use of head-mounted displays (HMDs) was considered an important extension of existing IGT technologies," scientists in Austria explained. "Several approaches to utilizing HMDs and modified medical devices for augmented reality (AR) visualization were implemented," including "video-see through systems, semitransparent mirrors, modified endoscopes, and modified operating microscopes."