Iridology or Iridodiagnosis is a diagnostic technique that works on the belief that the markings and patterns of the irises of the eyes correspond to various body parts. Iridology techniques are used by chiropractors, naturopaths, and physicians practicing alternative medicine techniques. Iridology is a non-invasive technique that makes use of iris charts in which the right iris has areas that correspond to body parts for the right side of the body and similar for the left iris. As with most branches of alternative medicine, iridology does not have any clinical data to back its claims of being a diagnostic tool. Practitioners claim to be able to reveal past medical problems and predict future illnesses with the help of iridology.