heory and Practice of Optics and Refraction by A. K. Khurana is a widely used textbook from the Modern System of Ophthalmology (MSO) Series, designed for undergraduate and postgraduate medical students. The book offers a clear and systematic approach to the principles of optics, refraction, and clinical applications in ophthalmology. It combines fundamental concepts with practical aspects, making it an essential guide for understanding visual optics, refractive errors, and modern corrective techniques.