Clinical Investigations on Squint is a comprehensive and pioneering work by Dr. C. Schweigger, translated from the original German by Emily J. Robinson. This book delves deeply into the clinical study and management of squint (strabismus), a condition characterized by the misalignment of the eyes. Drawing from years of clinical experience and observation, Dr. Schweigger presents a systematic exploration of the causes, manifestations, and treatment options for squint, making the book a valuable resource for ophthalmologists, medical students, and practitioners interested in ocular disorders. The text is structured to guide readers through the fundamental principles of ocular anatomy and physiology as they relate to squint, followed by detailed case studies and clinical observations. Dr. Schweigger discusses the various types of squint, including concomitant and paralytic forms, and provides insights into their differential diagnosis. The book emphasizes the importance of thorough clinical examination, including the use of innovative diagnostic techniques and instruments available at the time. A significant portion of the book is dedicated to therapeutic approaches, ranging from non-surgical interventions such as optical correction and exercises to surgical procedures aimed at correcting ocular misalignment. Dr. Schweigger critically evaluates the outcomes of different treatments, offering practical advice and cautionary notes based on his extensive clinical experience. Throughout the work, the author integrates theoretical knowledge with practical application, making complex concepts accessible to readers. The translation by Emily J. Robinson ensures that the original insights and nuances of Dr. Schweigger’s work are preserved for an English-speaking audience. Clinical Investigations on Squint stands as a landmark text in the history of ophthalmology, reflecting the scientific rigor and clinical acumen of its author. It remains a valuable historical reference for those interested in the evolution of strabismus diagnosis and management, as well as a testament to the enduring quest for understanding and treating visual disorders.