“Subjective Refraction and Prescribing Glasses: The Number One (or Number Two) Guide to Practical Techniques and Principles” is a comprehensive textbook on ophthalmology, specifically focusing on the techniques and practical aspects of subjective refraction and prescribing glasses. Authored by Richard J. Kolker, this third edition book offers clear explanations, tips, tricks, and best practices for those in the field. With case scenarios in a question and answer format, this book is a valuable resource for both novice and experienced ophthalmologists looking to improve their skills in the subjective refraction process. The book includes detailed information on practical optics, the use of the Jackson Cross Cylinder, plus and minus cylinder methods, and much more.