Peter Jackson-Main, who leads the Postgraduate Course in Iridology at CNM (College of Naturopathic Medicine), explains how the study of the iris can help practitioners to pinpoint the origin of health problems, and facilitates choice of the most suitable therapies.

What is Iridology?

Conventional science has as yet no full explanation for iris phenomena, recognizing the iris merely as a sphincter and dilator muscle whose function is to regulate the amount of light entering the inner chamber of the eye.

The link between eye (iris) colour and heredity is medically acknowledged, but this does not usually go any deeper than the basic iris colour, and takes no account of structure or secondary pigmentation, although some as yet little-known research in genetics and embryology1 has pointed to some emerging basic principles.

The eyes themselves are well known indicators of a variety of personal factors, including heredity - "she has her father's eyes!" Tired eyes, bloodshot eyes, lacklustre eyes, dark circles under the eyes, are all examples of the way that health status and vitality may be inferred from the eyes. When we say that there is a sparkle in someone's eyes we are getting the clear impression of laughter, joy, excitement or love. On the other hand, a glint in someone's eye can imply mischief or even malice.

From the earliest era of human civilisation, the eyes have been known for their ability to impart information about their owners. The Chinese had ways of discerning health tendencies from the size, shape and set of the eyes, and in the Ayurvedic tradition of India the colour of the eyes is part of the description of a person's Prakriti, or constitution2.

Modern Iridology, however, is probably a rather younger science. One reason for this is that the iris is a very small structure and relies upon magnification in order to reveal its secrets fully. Even in the mid nineteenth century, Ignatz Von Peczely, the acknowledged "Father of Iridology", had to make do with a mere 2x magnification. The later development of the optical and photographic sciences lent itself uniquely to the examination of the organ of sight itself, and was in fact necessary to the development of Iridology, as we know it today.

Every person's irides are unique. Amongst approximately seven billion human inhabitants of the Earth, not one has irides identical to yours. Not just the colours, but also the myriad structural variations which can be viewed in each iris (you do not even have two the same), are the genetically determined evidence of your uniqueness. It is estimated that some 200 differentiating signs may be charted in the average iris, and this has become the basis for the recent instalment of eye level cameras at cash points and border controls for reliable bio-identification. This means that the irides offer approximately ten times greater security of identification than does fingerprinting. The UK government's recently abandoned plans to issue identification cards issued to all citizens would have involved the inclusion of the individual's iris prints amongst other personal information encapsulated.

Diagnosis or Personal Assessment?

Iridologists act on the principle that what is necessary in determining a correct treatment and lifestyle strategy for any individual is a true assessment of that person's individuality, and the factors that have shaped his/her life in its uniqueness. These factors, a combination of what you were born with - your heredity - and what you have experienced through you life so far, Iridologists refer to as your constitution, and contemporary Iridology is actually the practice of using the irides to determine both natal constitution and the acquired phenomena that ensue from the conditions of stress and environment to which the individual is exposed throughout the course of life.

Contemporary Iridologists distance themselves from the notion of diagnosis, where that term merely means the simple identification of a named pathology by examination of the symptoms. Of greater interest are the functional dynamics of the organism, mediated by individual fluctuations in both somatic and psychic response to the environment, and in this hereditary and embryologic patterns of organ response are critical, and it is that the Iridological examination purports to read. This way we are enabled to get behind the symptoms, which are often no more than the body's attempted corrective response to various manifestations of stress, to the underlying causes of disease in the failure to adapt to such conditions, which frequently ensues from innate insufficiencies or susceptibilities.

It has been frequently noted that research programs set up to assess iridology fail to deliver a good account of it. This is very simply because such programs generally do not focus on the right outcome, preferring to tread the old path towards diagnostic absolutism in favour of a more functional approach that would discuss, for example, familial health trends and the impact of environment. Nevertheless, in Russia, for example, several studies have indeed validated the effectiveness of Iridology as a diagnostic tool, when intelligently combined with differential diagnostic investigations 3.

One of the most often stated criticisms of Iridology is that there is the tendency to overdiagnosis. This means that the Iridologist suddenly reveals a catalogue of complaints the patient never knew he had, causing considerable anxiety, and opening the practice to substantial criticism, especially when testing fails to confirm the diagnosis. Dr Joseph Deck, medical doctor and Iridology researcher in the mid 20th Century, and the chief proponent of the constitutional theory of Iridology, was keen to emphasise that iridological factors may be either manifest or latent 4. This means that any iridological observation needs to be tested against the following key parameters:

- Actual confirmed diagnoses and presenting symptoms
- Medical history
- Secondary symptoms that suggest underlying tendencies or pathologies (e.g. hypoglycaemia as a precursor to diabetes)
- Familial medical history
- Possible stress- or emotion-mediated pathologies

Only when all of these factors have been ruled out can we say with any certainty that we have exhaustively tested the hypothesis, and even then there may be, say in the case of familial history, multiple pathologies that can mask or override other specific susceptibilities (e.g. patient's relative may have been diabetic but died of cardiac failure before type II onset could fully develop).

A Tool for Effective Consultation

Of paramount importance in any medical consultation is not only correct diagnosis, but also the effective engagement of the patient in his or her healing process. Gaining compliance is one of the keys to therapeutic success, and is the much sought-after grail of effective practice. Human communication is known to be a complex affair, and that complexity is nowhere more urgently to be understood as in the therapeutic consultation. Amongst the many dynamics that apply here, the fact that individuals have preferences in terms of the way they understand the world and their place in it, is one factor that can be deployed towards maximum therapeutic effectives.Iridology offers two benefits in this regard:

1. A holistic assessment tool that seeks to harmonise the patient with her symptoms, her lifestyle, her family background and her environment, thus engaging all visible (and some not so visible) aspects of her experience of herself.s

2. A visual aid to communication, understanding and learning that acts as an analogue to personal experience. In linguistic terms, it may indeed be said that the link between the sign and the interpretation (meaning) is arbitrary, but the iridologist's experience is a powerful one in this regard: he points out the sign; he asks the question; the answer confirms the status; the patient understands. Understanding is next to compliance - once the patient sees the need to act, she will generally not waver.


We may not have all the answers in terms of the how or the why of Iridology. Medical research lets us down precisely because it asks the wrong questions, but further, because it does not understand the paradigm that Iridology asks us to consider. And yet I have taught Iridology to many medical practitioners and they are all too quick to see its relevance in practice. It has been shown in several studies (5) that medical practice often falls short of what patients really want, especially in the "bedside manner". Some have suggested that the reason so many are shifting their loyalty to the complementary and alternative sector is precisely because of this loss of faith in the dominant paradigm (6), and the general manner of its presentation.

Iridology may help to correct this imbalance. It is after all partly at least the product of medicine itself - it uses similar language, its concepts are related to mainstream medical theory, and medical doctors throughout the last one hundred and fifty years have contributed to the substantial body of knowledge that we now command within its academy.

For the complementary health practitioner, and more especially to the Naturopathic practitioner, with an emphasis on the primacy of the patient in the healing endeavour, it is in my view unparalleled as a method that can unify patient experience, medical and ancestral history, effective therapeutic intervention, and patient compliance.Copyright Peter Jackson-Main 2013

About the writer

Peter Jackson-Main is a renowned Master Herbalist, Iridologist, natural healer, author, and practitioner. He is also Course Leader and Senior Lecturer in Herbal Medicine at CNM (College of Naturopathic Medicine), where he also leads the Postgraduate Course in Iridology.

Iridology is a short Postgraduate Course at CNM in London, open to qualified practitioners and students of relevant therapies, some of whom may be exempt from certain modules. For more information about CNM courses, visit www.naturopathy-uk.com or call 01342 410 505.


1 Mats Larsson, Genetic correlations among texture characteristics in the human iris, Molecular Vision 2004; 10:821-31 - http://www.molvis.org/molvis/v10/a98 - ©2004 Molecular Vision Received 26 March 2004 | Accepted 18 October 2004 | Published 2 November 2004

2 Sebastian Pole, 2006, Ayurvedic Medicine, the principles of traditional practice, Elsevier, London

3 Grigoriy Abramov, Iridology and facts, http://www.iridologyinternational.com/content/iridology-and-facts-grigoriy-abramov Retrieved 5.6.13

4 Joseph Deck, 1965, The Principles of Iris Diagnosis, author pub.

5 McKinley, Robert K and Middleton, John F, 1999, What do patients want from Doctors? Content analysis of written patient agendas for the consultation, in The British Journal of General Practice, October 1999, pp. 786-800, accessed online 30.12.12 at:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1313530/pdf/10885083.pdf accessed 31.12.12

6 Cant, S. and Sharma, U., (1995), Reflexivity, Ethnography and the Professions (Complementary Medicine). Watching you watching me watching you (and writing about both of us), in The Sociological Review, Vol. 2, Issue 6, (1998), pp.244 - 263