Section 4 of the Academy's Basic and Clinical Science Course™ (BCSC®) presents materials in 2 parts: Part I, Ophthalmic Pathology; and Part II, Intraocular Tumors. The hierarchy of the chapters in Part I moves from general to specific to help clinicians derive a differential diagnosis for a specific issue. Part II is a compilation of selected clinical aspects of importance to the general ophthalmologist, this section contains extensive discussion of intraocular tumors.BCSC Section 4 also links selected content to the Academy’s online Pathology Atlas, which contains supplemental images, case studies, and other resources to help enhance a readers understanding. Symbols throughout the book indicate where readers can find supplemental content in the Atlas. Additionally, Section 4 contains Clinical Pearls, which identify information with direct relevance to clinical practice.Chapter Two has a Quick-Start Guide that outlines pathology in an easy-to-follow format, provides a glossary of select pathology terminology, and contains new features, such as Key Points icons and Take Note boxes, which identify important information.Section 4 of the BCSC includes 10 activities and 11 videos. Additional educational activities, including self-assessment modules and videos, facilitate learning key concepts in ophthalmic pathology.About the BCSCThe Academy’s Basic and Clinical Science Course™ is ophthalmology’s definitive source of clinical information. Practicing ophthalmologists and residents worldwide use the BCSC® to ensure the highest-quality patient care.