Major Revision This year Section 3 is updated to include nine videos, a Quick-Start guide to optics and how to refract, and each chapter now includes highlights and a glossary. This section provides a comprehensive overview of clinical optics, including current applications of optical phenomena such as lasers, spectacles, IOLs and refractive surgery. Presents optics of the human eye; basic concepts of geometric optics; ophthalmic instruments and contact lenses. Vision rehabilitation is also discussed. Includes real-life clinical examples, figures and learning exercises to help gauge your understanding of the material. Upon completion of Section 3, readers should be able to: Outline the principles of light propagation and image formation and work through some of the fundamental equations that describe or measure such properties as refraction, reflection, magnification and vergence Define the various types of visual perception and function, including visual acuity, brightness sensitivity, color perception and contrast sensitivity *Explain the optical principles underlying various modalities of refractive correction: spectacles, contact lenses, intraocular lenses and refractive surgery Recently revised: 2018 2019 Section chair: Scott E. Brodie, MD, PhD