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.