This article is from the Alternative Medicine Therapies guide.
Iridology is the study of the colored part of the eye (called the iris) to determine potential health problems. Iridologists believe that changing patterns and markings in the iris can be used to reveal emerging conditions in every part of the body and to identify inherited weaknesses that may lead to physical and emotional disorders.
Iridology cannot detect a specific disease. Rather, it is a preventive practice that helps people to understand their basic health issues so that they can seek treatment, if necessary, from the appropriate specialist. According to iridologists, if a health problem is detected at an early stage, something can then be done to prevent it from becoming a full-blown disease.
The idea that the eyes are a mirror to the body is an ancient one: The Greek physician Hippocrates was known to examine patients' eyes for signs of illness. It wasn't until 1670, however, that the first actual medical reference to iridology as a diagnostic tool appeared in German physician Phillipus Meyens' book Chiromatica Medica.
In the late-19th century Hungarian physician Ignatz von Peczely and Swedish clergyman Nils Liljequist independently advanced theories connecting the markings of the iris with tendencies toward specific ailments. Both men's interests stemmed from experiences in their childhoods.
As a boy, Peczely accidentally broke the leg of an owl and then noticed a black mark that subsequently appeared in the bird's iris. Later, in his medical practice, he noted similar marks in the eyes of his human patients who'd suffered a fracture. For his part, Liljequist contracted malaria in his teens and was treated with quinine and iodine. As the drugs accumulated in his system, he noticed that his blue eyes were turning a darker color. After he later became a homeopath, he found similar reactions in his patients as well.
Today, modern iridology is practiced far more widely in Europe than in the United States, with Germany contributing most of the research in the field during the past century. This is in part due to the influence of the German minister Pastor Felke, who developed a form of homeopathy for treating specific iris indications in the early 1900s. (The Pastor Felke Institute in Heimshiem, Germany, is currently one the leading centers of iridologic research and training, and carries on Felke's work.) In addition, German naturopath Josef Deck's books Differentiation of the Iris Signs and Elements of Irisdiagnosis, first published the 1930s, continue to be the standard textbooks on the subject.
Iridology first became known in the United States in the 1950's, when Bernard Jensen, an American chiropractor, began giving classes in his own method, which mainly concentrates on iris color, the body's exposure to toxins, and use of natural foods as detoxifiers. Although Jensen's concepts have never been fully accepted by his European counterparts, most American iridologists have been trained using Jensen's techniques.