Merging principles of geometrical and physical optics with hands-on design insights, this guide demystifies AR and VR eyewear displays. It examines optical components, human vision metrics, microdisplays and diverse optical architectures, charting a course from theoretical concepts to tangible products. Optical Design of Eyewear Displays is the first comprehensive resource dedicated to the optical engineering of modern augmented- and virtual-reality eyewear. It combines the core principles of geometrical and physical optics with practical design insight, showing how theory translates into the function and form of modern eyewear displays. Covering optical components, the human visual system, design metrics, and microdisplays, as well as optical architectures ranging from freespace to lightguide systems, the book traces the complete journey from principle to product. It draws on decades of innovation and experience and serves as both a reference and guide for optical engineers, researchers, and students, and as an indispensable resource for anyone contributing to the broader ecosystem that connects optics, electronics, and artificial intelligence in next-generation eyewear display technologies.