Section 13 of the Academy's Basic and Clinical Science Course™ (BCSC®) covers the science of refractive surgery, examines specific procedures and potential complications in refractive surgery as well as refractive surgery in ocular and systemic disease, and accommodative and nonaccommodative treatment of presbyopia. In addition, the book includes information on lens implants. This major revision features a new discussion of ray tracing–guided ablations and outcomes. Several topics have been updated and expanded, such as the discussions of surface ablation over previous photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK), light adjustable lenses, medical treatments for presbyopia, and presbyopia correction. BCSC Section 13 includes 3 case reports in the new online Appendix that address and demonstrate LASIK treatment customization using wavefront, topography, and ray-tracing technologies. It also features a chapter focusing on keratorefractive lenticule extraction (KLEx), a review of advances in intraocular lens (IOL) technology, and coverage of intraocular refractive surgery. Deepen your understanding with 17 interactive online activities and videos (sample), which include a new interactive case study on epithelial ingrowth and a new video on the insertion of a presbyopia-correcting extended depth of focus IOL (EDOF IOL). Both print and eBook users can access the videos and activities. Upon completion of Section 13, readers should be able to:State the contributions of the cornea’s shape and tissue layers to the optics of the eye and how these components are affected by biomechanically by different types of keratorefractive proceduresDescribe the basic concepts of wavefront analysis and its relationship to different types of optical aberrationsIdentify the general types of lasers used in refractive surgeries