2 Benefits

Practitioners of iridology point to the following benefits of iridology:

1. Their examination is not invasive. The only thing patients have to tolerate is light being shone in the eyes.

2. Iridologists aim to keep the patient well. They try to discover imbalances or weaknesses in the body before they develop into serious medical problems. Of course prevention of health problems is a central concept of all schools of medicine. Iridologists' advice on how to keep the patient well is frequently good. For example, they may recommend a good diet, drinking plenty of water, and moderate exercise.

3. A visit to an iridologist can have a placebo effect. If patients think that by following the iridologists advice they will feel better then there is some probability that they will. The size and likelihood of this placebo effect will depend on the patient's suggestibility, his belief in this particular health system and the behaviour of the therapist, but also e.g on whether a fee was charged for the visit. Placebo effects are well recognised and researched and are of significance in all branches of healthcare (including complementary forms).

3 History

Examining a person's eyes to help determine their health is an ancient practice dating back at least as far as the ancient Greeks.

The first explicit description of iridological principles such as homolaterality (without using the word iridology) are found in Chiromatica Medica , a famous work published in 1665 and reprinted in 1670 and 1691 by Philippus Meyeus (Philip Meyen von Coburg).

The first use of the word Augendiagnostik ("eye diagnosis," loosely translated as iridology) began with Ignatz von Péczely , a 19th-century Hungarian physician. The most common story is that he got the idea for this diagnostic tool after seeing similar streaks in the eyes of a man he was treating for a broken leg and the eyes of an owl whose leg von Péczely had broken many years before. At the First International Iridological Congress of Iridology, Ignaz von Péczely's nephew, Dr August von Péczely, dismissed this myth as an apocryphal, and maintained that such claims were irreproducible.

German contribution in the Naturheilkunde field is due to a minister Pastor Felke , who developed a form of homeopathy for treating specific illnesses and described new iris signs in the early 1900s. However, Pastor Felke was subject to long and bitter litigation. The Pastor Felke Institute in Heimshiem, Germany was established as a leading center of iridologic research and training.

Iridology became popular in the United States in the 1950s, when Bernard Jensen, an American chiropractor, began giving classes in his own method. This is in direct relationship with P. Johannes Thiel, Eduard Lahn (becoming an American under the name of Edward Lane) and J Haskell Kritzer. Jensen insisted on the body's exposure to toxins, and the use of natural foods as detoxifiers.

Few medical researchers managed to secure funding to study the possible non-visual functions of the eye. In a paper published in Medical Hypotheses (Waniek ², 1987), one such group tried to explain the observed patterns of iris transparency that distribute light into the ora serrata (the edge of the optic retina) by postulating a so-called functio ocularis systemica. Based on this hypothesis, the researchers have developed the experimental trans-iridal light therapy method; however, no independent confirmation of the theory and method exists to date. Other results from the mentioned research include early attempts at computerized iris imaging for the purpose of iridologic diagnosis (Popescu et al. ³, 1986) .

3.1 Mainstream medical examination of the eye

Although mainstream medicine considers iridology as quackery, there are many times when a conventional doctor will examine the eyes of a patient. The most obvious example would be diseases of the eye. Medical doctors performing iris examinations in order to determine eye problems, may use biomicroscopes and gonioscopes . Examination of eyes is a part of many clinical examinations, attempting to answer questions raised by jaundice, excess cholesterol, general neurologic conditions and more specific syndromes, including Foster-Kennedy , Claude-Bernard-Horner , Adie's etc.

The responsiveness of the pupil and its dilation are also often checked, mostly after accidents involving head trauma and suspected alcohol- or drug abuse, because they give a good indication of a patient's consciousness.

4 Criticism

The majority of medical doctors reject all the claims of all branches of iridology en bloc and label them as pseudoscience or even quackery. Iridologists are rarely medical doctors; many training centers exist, but iridology is neither taught in mainstream medical schools, nor acknowledged by official medical organizations as a valid medical technique.

Mainstream medicine is dismissive of iridology largely because published studies have indicated a lack of success for the iridological claims.

5 Scientific research into iridology

Scientific research into iridology has shown mostly, but not entirely, negative results. However, all double blinded highly rigorous tests of iridology have in fact failed to find any statistical significance to the claim that iridology is in any way efficacious.

In a study published in the Journal of the American Medical Association (Simon et al. ⁴, 1979), three well qualified iridologists incorrectly identified kidney disease in photographs of irises and often disagreed with each other. The researchers concluded: "iridology was neither selective nor specific, and the likelihood of correct detection was statistically no better than chance." Iridologists defended themselves by stating that they needed live examinations and that their approach was valid for predictions of health, not of disease tags once the disease was developed and even complicated. However the three iridologists concerned did not state that before the study took place.

Another study was published in the British Medical Journal (Knipschild ⁵, 1988). Paul Knipschild MD, of the University of Limburg in Maastricht, selected 39 patients who were due to have their gall bladder removed the following day, because of suspected gallstones. He also selected a group of people who did not have diseased gall bladders to act as a control. A group of 5 iridologists examined a series of slides of both groups irises. The iridologists were not able to identify correctly which patients had gall bladder problems and which had healthy gall bladders. For example one of iridologists diagnosed 49% of the patients with gall stones as having them and 51% as not having them. He diagnosed 51% of the control group as having gall bladder problems and 49% as not. Dr Knipschild concluded: "this study showed that iridology is not a useful diagnostic aid." Iridologists defended themselves with the same considerations as above, but also attacked the methodology of the study.

Ernst ¹, 2000, said: "Does iridology work? [...] This search strategy resulted in 77 publications on the subject of iridology. [...] All of the uncontrolled studies and several of the unmasked experiments suggested that iridology was a valid diagnostic tool. Such investigations are wide open to bias. The discussion that follows refers to the 4 controlled, masked evaluations of the diagnostic validity of iridology. [...] In conclusion, few controlled studies with masked evaluation of diagnostic validity have been published. None have found any benefit from iridology. As iridology has the potential for causing personal and economic harm, patients and therapists should be discouraged from using it."

Demea ⁶, 2002, showed more positive results for iridology: "The research proposal is to evaluate the association between certain irian signs and general pathology of studied patients. [...] There were studied 57 hospitalized patients [...] The correlations resulted from, shows a high connection between the irian constitution establish[ed] through iridological criteria and the existent pathology. [...] Iris examination can be very useful for diagnosis of a certain general pathology, in a holistic approach of the patient." (translation as per abstract) However, the absence of the required formal criteria for reliable evidence in health care (blindedness, lack of bias, statistical significance of findings, etc.) makes this study not very useful in the eyes of sceptics.

6 References

1. Ernst E. Iridology: not useful and potentially harmful. Arch. Ophthalmol. 2000 Jan;118(1):120-1. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids= } Medline abstract] (PMID })
2. Waniek, D.A., Medical Hypotheses 1987;23(1): 309-312. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids= } Medline abstract] (PMID })
3. Popescu, M.P.; Waniek D.A., Rev Chir Oncol Radiol O R L Oftalmol Stomatol Ser Oftalmol 1986;30(1): 29-33. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids= } Medline abstract] (PMID }) (in Romanian)
4. Simon A., Worthen D.M., Mitas JA 2nd. An evaluation of iridology. JAMA. 1979 Sep 8;242(13):1385-9. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids= } Medline abstract] (PMID })
5. Knipschild P. Looking for gall bladder disease in the patient's iris. BMJ. 1988 Dec 17;297(6663):1578-81. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids= } Medline abstract] (PMID })
6. Demea S. [Correlation between iridology and general pathology] Oftalmologia. 2002;55(4):64-9. Abstract (from MEDLINE) (in Romanian)

7 See also

• Ophthalmology

8 External links

8.1 Pro

• Western Medicine looks at Iridology ... by Bill Caradonna R.Ph. (Several more rebuttals of official critics of iridology are found at the same resource online.)
• Is the Iris a Receptor? by Vincenzo Di Spazio (2000)
• Iridology by Dr Lisa Niebergall
• Celestial Healing site about iridology (source of the iris charts used in this article)
• Canadian Journal of the Science and Practice of Iridology (a good resource, no longer available as hard print)
• Canadian Institute of Iridology (a source for Courses in Canada)

8.2 Con

• The Skeptics Dictionary
• Iridology (small PDF file duplicating Knipschild and Simon data, with no independent additions, but with valuable illustrations)
• Iridology Is Nonsense article on Quackwatch by Stephen Barrett, M.D.