Reading the Iris

No two irises are alike. The delicate pattern of fibres, furrows, rings and flecks in the coloured part of your eye is so individual that it's used in airports and banks to identify people, and is far more distinctive than a fingerprint. Even your own left and right eyes differ. The ancient Greeks named the iris after the goddess of the rainbow, the messenger between earth and sky; an old German name for it is Regenbogenhaut, "rainbow skin". For more than a century, naturopaths have looked into this personal rainbow for something more: a picture of the person behind it.

A boy, an owl and a question

Iridology began in Hungary in the mid-nineteenth century. As the story goes, an 11-year-old boy called Ignatz von Peczely accidentally broke the leg of an owl while freeing it from a trap. Nursing it back to health in his garden, he noticed a dark stripe in the owl's iris, which slowly faded to white as the leg healed.

Von Peczely went on to train in homeopathy and then medicine, and spent his life mapping the irises of his patients. In 1880 he published his findings, along with one of the first iris charts, and many of his organ positions are still used today. Yet he remained puzzled to the end. His last words are said to have been: "Here is the sign, but where is the disease?"

Others took up the work: the Swedish clergyman and healer Nils Liljequist; Henry Lindlahr, who brought iridology to his famous Nature Cure sanatorium in Chicago; and the American naturopath Bernard Jensen, whose detailed charts and 1982 textbook made iridology known around the world.¹

From disease to constitution

Von Peczely's question turned out to be an important one. The early iridologists believed that marks in the iris reflected a person's health at that moment, and would come and go with illness. But when the iris was photographed over many years, it became clear that most iris features barely change at all. Many can be seen in young children and remain the same into old age.

In 1965, the German doctor Josef Deck offered a new explanation: the iris reflects our constitution, the inherited strengths, sensitivities and tendencies we are born with, passed down through our family line, rather than the diseases we have now.² This genetic model shapes how iridology is taught and practised today. It echoes an idea attributed to Hippocrates: that it matters more to know what kind of person has a disease than what disease the person has.

Modern science offers some intriguing support for the idea that the iris is shaped by our genes. Twin studies show that iris features such as crypts and furrows are strongly inherited,³ and in a Swedish study of over 400 people, these features were even linked with aspects of personality, such as warmth and impulsiveness.⁴

The iris doesn't tell your whole story, but it can be a beautiful place to begin the conversation.

A map in the eye

The part of the iris an iridologist studies is the stroma, a layer of thousands of fine, radiating fibres, richly supplied with nerves. It is read in two ways:

• In rings. The iris is divided into circular zones. Closest to the pupil lies the "nutritive" zone, linked with the stomach and intestines. It is bordered by the collarette, a wavy ring sometimes called the autonomic nerve wreath, whose shape is read as a guide to digestion and the nervous system. Beyond it lie the "utilisation" zone, linked with the blood, glands and major organs, and the outer "elimination" zone, linked with the lymph and skin.
• Like a clock face. The iris is also divided into sectors, each corresponding to a part of the body, with the head and brain at the top. The right iris is traditionally linked with the right side of the body, and the left with the left.

The pupil is read too. A pupil smaller or larger than about a quarter of the iris width is traditionally linked with the balance between the calming and alerting branches of the nervous system.

Three layers of constitution

In Deck's system, your iris constitution is described on three levels:

• Constitution, seen in colour. Your basic iris colour, which usually stays the same throughout life.
• Disposition, seen in structure. The pattern of the fibres. A fine, dense weave is traditionally linked with a sensitive, highly responsive nervous system; a looser, more open weave with flexibility, adaptability and connective tissue that may need extra support. Other patterns are linked with the digestive and hormonal systems.
• Diathesis, seen in overlay. Additional features such as white flecks, clouds, rings or patches of colour, traditionally linked with a tendency to accumulate waste or with particular body systems. Not everyone has one, and some can develop over the years.

The three colour types

Iridology recognises three true iris colours, each traditionally associated with particular tendencies when life, diet or stress put the body under strain:

• Blue or blue-grey: the lymphatic type. An iris with little pigment, common in people whose ancestors lived in cooler climates. It is associated with the lymphatic and immune systems: a tendency in childhood to tonsil, ear, nose and throat problems, and later to allergies, hay fever, eczema, catarrh, food sensitivities and, in later life, stiff joints. Naturopathic care focuses on supporting lymph drainage, immunity and digestion, with plenty of water, movement, deep breathing, dry skin brushing and colourful, antioxidant-rich foods. (See Skin Deep and Born to Move.)
• Dark brown: the haematogenic type. A fully pigmented iris, common in people whose ancestors lived in hot, sunny climates. It is associated with the blood and circulation: a tendency, under strain, towards sluggish circulation and cold hands and feet, anaemia, raised cholesterol and blood pressure, blood sugar problems and, in women, heavy or clotted periods. Naturopathic care focuses on supporting the liver, circulation, blood sugar balance and hormones, with daily movement, warming spices, bitter foods and plenty of green vegetables. (See Balancing the Sugar Seesaw.)
• Hazel or light brown: the mixed biliary type. A partly pigmented iris, often brown around the pupil fading to green or blue further out, carrying elements of both. It is associated with digestion, especially the liver, gall bladder and pancreas: a tendency towards bloating, wind, reflux, sluggish bowels, erratic energy and sugar cravings. Naturopathic care focuses on digestion: eating calmly, not overeating, beginning meals with bitter, sour or fermented foods, and supporting the liver. (See Bitter Is Better and You Are What You Absorb.)

Herbs are often chosen to suit each type, but the right herb also depends on the whole person, their energetics and any medicines they take, so it's always best to be guided by a qualified practitioner rather than self-prescribing. (See The Architecture of Balance.)

Signs, not sentences

Beyond colour and structure, an iridologist may notice up to 200 individual features: small hollows in the fibres called lacunae, flecks of coloured pigment, circular "stress" furrows, white rings near the edge, and the shape of the collarette and pupil. Traditionally, a hollow is read as an area of inherited lower resistance that may benefit from extra care, and a pigment as a tendency to accumulation or sluggishness.

Good iridology training is emphatic about how these signs should be used:

• A sign is not a disease. Many signs never become symptoms in a person's lifetime, especially when they look after themselves. Some reflect tendencies seen in parents or grandparents.
• Questions, not statements. A practitioner asks gentle questions, about symptoms, family history and what you've noticed, rather than telling you what is wrong.
• Positive language. The same feature can be read as a vulnerability or as a strength, such as sensitivity, openness or adaptability, and a skilled practitioner will help you see both.
• No disease diagnosis. Iridology should never be used to diagnose cancer or any other specific disease, nor to track your progress: the iris simply doesn't change that quickly.

What the research says

It's important to be honest about the evidence. When researchers have tested whether iridologists can identify specific diseases, such as kidney disease or cancer, from photographs of the iris, they have not been able to do so reliably,^5,6 and a review of the controlled studies reached the same conclusion.⁷ This is entirely in keeping with Deck's genetic model: if the iris reflects the constitution you were born with rather than the illness you have now, we wouldn't expect it to diagnose disease.

Whether the iris can reliably reveal inherited constitutional tendencies is a far harder question to study, and the research simply hasn't been done in a rigorous way. So iridology is best seen for what it is: a traditional, individual and often illuminating way of looking at a person, used as one lens among many, and never in place of proper medical tests.

The eyes really are a window

Modern medicine has its own ways of reading the eyes:

• The retina, at the back of the eye, is the only place blood vessels can be seen directly without a scan, and changes there can be an early sign of diabetes or high blood pressure. It's one reason regular eye tests with an optometrist matter.
• A pale ring around the edge of the iris in a younger person can be a sign of raised cholesterol, something iridologists have long called the "cholesterol ring".
• Pupils that suddenly become unequal in size need urgent medical attention, as this can be a sign of a problem in the brain or nerves.

What to expect from an iris reading

• A close look. Your irises are examined with a magnifier and gentle light, or photographed, often so you can see them on screen too. Let the practitioner know if you're sensitive to light, or if you have epilepsy and flash photography is used.
• A conversation, not a verdict. What's seen in the iris is explored alongside your health history, family history, diet and lifestyle, never on its own.
• Practical, positive guidance. The insights help shape advice that suits your constitution, from food and lifestyle to herbs.
• Further advice where needed. If anything you describe needs medical investigation, a good practitioner will always encourage you to seek it.

At Rootwise, the iris is one part of a much bigger picture. Alongside your history, symptoms and, where helpful, modern testing, it can help us understand the constitution you were born with, and build a plan that works with your nature rather than against it.