The competent and intelligent optical design of today's state-of-the-art products requires an understanding of optical aberrations. This accessible book provides an excellent introduction to the wave theory of aberrations and will be valuable to graduate students in optical engineering, as well as to researchers and technicians in academia and industry interested in optical imaging systems. Using a logical structure, uniform mathematical notation and high quality figures, the author helps readers to learn the theory of optical aberrations in a modern and efficient manner. In addition to essential topics such as the aberration function, wave aberrations, ray caustics and aberration coefficients, this text covers pupil aberrations, the irradiance function, aberration fields and polarization aberrations. It also provides a historical perspective by explaining the discovery of aberrations and two chapters provide insight into classical image formation; these topics of discussion are often missing in comparable books.