Iridology is a diagnostic method in which specific areas of the eye's iris correspond to various organs of the body, so that studying the markings of the iris can be used to identify dysfunction elsewhere. Used by physicians, naturopaths, chiropractors, and other healers, iridology is a noninvasive technique that supplies information not clearly delineated by other means regarding the condition of the body. Based on this information, the practitioner can make recommendations for changes in diet or lifestyle as a preventative approach.