Basic refraction is a foundational part of ophthalmology, and yet beginning ophthalmology residents and ophthalmic technicians are often left on their own to learn the finer points. Despite being core skills, the techniques and practical aspects of subjective refraction and prescribing glasses are often developed by trial and error, if they are developed at all. Subjective Refraction and Prescribing Glasses: The Number One (or Number Two) Guide to Practical Techniques and Principles, Third Edition is designed as a complete guide to those essential skills, offering everything from basic terminology to tips, tricks, and best practices. This updated Third Edition has been expanded in every section with thoughtful, practical advice, and has case scenarios, in a question and answer format, of situations encountered with real-world patients. It is the most comprehensive review of clinical subjective refraction to date. Drs. Richard Kolker and Andrew Kolker together have nearly 50 years of experience in the practice of ophthalmology and bring both the fresh eyes of a beginning ophthalmologist and the experience of a seasoned veteran to this Third Edition. While new residents and technicians will appreciate the thorough explanation of refractive fundamentals, even expert ophthalmologists will appreciate the practical tips that may have never occurred to them. Included are: Very clear, easy-to-read, practical explanations of the subjective refraction process Basic practical optics to explain the steps of subjective refraction The Jackson Cross Cylinder made easy to understand and use Plus and mInus cylinder methods discussed separately and color coded for quick identification An Appendix with a primer on retinoscopy and how to use the manual lensometer The art of subjective refraction and prescribing glasses Subjective Refraction and Prescribing Glasses: The Number One (or Number Two) Guide to Practical Techniques and Principles, Third Edition is the definitive guide to the often neglected skills involved in clinical subjective refraction. Residents and technicians will find it a critical guide in their learning process, but even seasoned ophthalmologists can benefit from the tips and tricks enclosed within.