Iridology (sometimes referred to as iris diagnosis or iris analysis) is based on the notion that every area of the body is represented by a corresponding area in the iris of the eye (the colored area around the pupil). According to this viewpoint, a person’s state of health and disease can be diagnosed from the color and location of various pigment flecks in the eye. Iridology practitioners claim to diagnose “imbalances” that can be treated with vitamins, minerals, herbs, and similar products. Some iridologists claim that the eyes can reveal whether a person is introverted or extroverted. Some iridologists claim to diagnose “constitutional types” that reflect “inherent tendencies” toward various diseases and offer treatment to supposedly reduce these tendencies Some also claim that the eye markings can reveal a complete history of past illnesses as well as previous treatment. 

Iridology charts—dozens of which exist—vary somewhat in the location and interpretation of their iris signs. Practitioners typically use a magnifying device to examine the eyes and may take photographs. Some use a computer to help them analyze their photographs and select the products they recommend. 

Sclerology is similar to iridology but interprets the shape and condition of blood vessels on the white portion (sclera) of the eyeball. 

Bernard Jensen, D.C. (1908-2001), the leading American iridologist, stated that “Nature has provided us with a miniature television screen showing the most remote portions of the body by way of nerve reflex responses.” He also claimed that iridology analyses were more reliable and “offer much more information about the state of the body than do the examinations of Western medicine.” 

 It is not unusual for patients to conclude that iridology findings are accurate. Iridologists commonly float general statements (such as “There appears to be a problem in your abdomen”) that the patient interprets as related to specific concerns. However, well-designed studies have found that when patients with and without medically proven diseases were examined, the practitioners were unable to determine which was which. 

In 1979, for example, Jensen and two other proponents examined photographs of the eyes of 143 persons in an attempt to determine which ones had kidney impairments. (Forty-eight had been diagnosed with a standard kidney function test, and the rest had normal function.) The three iridologists performed no better than would be expected by random guessing at detecting which patients had kidney disease and which did not. One iridologist, for example, decided that 88% of the normal patients had kidney disease, while another judged that 74% of patients who were sick enough to need artificial kidney treatment were normal. 

In the late 1980s, five leading Dutch iridologists failed a similar test in which they were shown stereo color slides of the right iris of 78 people, half of whom had gallbladder disease. None of the five could consistently distinguish between the patients with gallbladder disease and the people who were healthy. Nor did they agree with each other about which was which. 

In a study published in 2005, an experienced practitioner correctly diagnosed cancer in only 3 of 68 people who had medically proven cancers of the breast, ovary, uterus, prostate, or colon/rectum. 

Such negative results are not surprising because there are no known anatomic or physiologic mechanisms by which body organs can be represented or transmit their health status to specific locations in the iris. 

Iridology poses serious risks. Incorrect diagnoses can unnecessarily frighten people, cause them to waste money seeking medical care for nonexistent conditions, and steer them away from necessary medical care when a real problem is overlooked. SfSBM advises consumers to avoid iridology.

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