An exam prep textbook that was written by an optician for opticians. Easy to understand, this book is developed so that anyone can relate their day to day tasks to the topics covered by the National Opticianry Certification Exam given by the American Board of Opticianry. It is not just a review book but a training manual that takes the anxiety out of prism, Prentice's Rule, lensometry, and a host of other topics.