Andreas Georgiou is an independent consultant with Reality Optics, Ltd., and has a particular interest in computational problems in ray and wave optical design. He worked in diffractive optics for over two decades and more than a decade in mixed-reality optics. Georgiou enjoys making new ideas into operating prototypes by combining physics, mathematics, engineering, and software. He particularly likes working with head-mounted displays, three-dimensional displays, sensors, and everything unusual with lenses and gratings inside. Before his current position, Georgiou worked with many product groups at Microsoft (Surface, HoloLens, Azure, and Kinect), developed micro-confocal endoscopes for surgery, designed space instruments for Mars, and created the first genuinely holographic display. He obtained his PhD in optics from the University of Cambridge. He is also an Engineering Research Fellow at Robinson College, Cambridge, where he continues to teach. He has more than 30 patents and more than 20 peer-reviewed publications on head-mounted displays, data storage, holographic displays, and free-space optical communications.