Iridology analyzes the colored part of the eyes (iris). It is an alternative medicine technique that can be used as an aid in the current medical practice. This work is focused on Iridology’s basic concepts: the 13 reference conformations and their relationship with the pupil. This manual, written in an accessible language, isn’t directed only to health operators but also to all the people who love wellbeing and are interested in non-invasive techniques. The work includes illustrations, 25 explicative tables and 142 commented iris images.