ABSTRACT
This chapter discusses the relevant properties of augmented reality (AR) displays and present representative milestones for systems in these categories with a focus on medical applications. Visual displays are an essential part of AR systems that enable the fusion of real and virtual images into a consistent user experience. As early as 1938, the Austrian mathematician Steinhaus described the first setup of augmenting imaging data registered to an object with a geometric layout aimed at revealing a bullet inside a patient by visually overlaying a pointer on the position of the invisible bullet. Integrating optical coherence tomography into the optical path of operating microscopes enables the acquisition and visualization of highly detailed surface features. The first head-mounted display (HMD)-based AR system was described by Ivan Sutherland in 1968. A stereoscopic monochrome HMD combined real and virtual images by means of a semitransparent mirror, which also is referred to as optical see-through HMD.
