Even when technology has developed more accurate machines for diagnose and follow-up glaucoma and other neuro-ophth diseases, this is a really great book for understand how automated perimetry works. Humphrey machines are still working in almost every country, but not all users knows how to interpretate its results. This book not only explains in a very simple way what does it means each parameter and index, but also gives you a strong base for understand visual field deffects caused by abnormalities at any level of the visual pathway.