The textbook "Gonioscopy" provides a comprehensive introduction to the technique of gonioscopy, which is crucial for the differentiated diagnosis of glaucoma diseases. It explains in detail how the examination of the anterior chamber angle is conducted and what anatomical considerations must be taken into account. The book discusses the effects of age, developmental disorders, and other pathological changes on the chamber angle, placing particular emphasis on distinguishing between primary and secondary open-angle glaucoma as well as angle-closure glaucoma. Through numerous photographs and illustrations, the role of gonioscopy in assessing the chamber angle is vividly presented. Additionally, the relevance of knowledge about the chamber angle for laser therapeutic measures and surgical interventions is thoroughly addressed. The information is presented in a way that allows professionals to effectively apply the technique in diagnosis and treatment.