The iris is like a television which receives signals from a satellite over the world. If you could see the world the way the satellite sees it, you would see gorgeous blue oceans, land masses of various colours, and clouds obscuring some areas. If you looked closely you’d see that some rivers and lakes weren’t as clear and blue as others, perhaps due to sedimentation or pollution. Some land areas would be brown, some would be full of lush green forests. A high powered satellite might be able to see electricity substations and communications lines.

The view that an iridologist has when examining your iris is similar in concept. The iris provides a miniature picture of the state of health of your own private world: your body. Your iridologist can see gorgeous clean healthy areas, full of lush regular fibres, perhaps also some darker recessed areas, or areas tinted with a yellowish or brownish haze. Each area of the iris shows the tissue state of an area or organ of your body. The right iris shows the tissue state of the organs of the right side of the body, the left iris shows the left side.

To an iridologist, there are only two iris colours: blue and brown. If you have hazel or green eyes, an iridologist would recognise that you actually have blue irises that are showing signs indicative of less than optimal health. Having said that, you should know that not every brown fleck in your iris has a meaning, so don’t rush to the mirror and start worrying about your health! Instead, go to a qualified iridologist and have your irises assessed and explained to you.

Some of the things that an iridologist can determine from your irises include:

  • Toxins accumulating in tissues
  • Under-functioning or over-working organs or tissues
  • Inflammation in the body
  • Stress levels and how you’re handling them
  • Genetic weaknesses and predispositions – by knowing these in advance, you can take appropriate action to avoid illnesses
  • Past injuries and how well they’ve healed
  • Digestive and eliminative systems and how well they’re functioning
  • Muscle cramps and their locations
  • Lymphatic system performance
  • Spinal health
  • Blood circulation to different areas of the body

Note that there are also some things that cannot be determined from the iris:

  • Pregnancy
  • Cancerous tumours
  • Sex of individual (this is only relevant when viewing an iris photo. Otherwise it’s usually obvious from looking at a person what sex they are!)
  • Disease diagnosis

The last point is very important. Iridology is a tool to gather information about the tissue state of the body. It does not provide a diagnosis.

How the eye mirrors the health of the body

The precise physiological mechanism that explains how the iris is able to register the tissue state of the body has not yet been determined, however we do know that the central nervous system and the eye are intimately related. In fact, in the embryonic state, the eye develops from the same tissue as the brain does.

In order to discuss the nerves that connect to and affect the iris, we must first mention that there are three main divisions of nerves affecting the eye:

  • Motor nerves – these are the three cranial nerves that move the eyeball: oculomotor, trochlear and abducens.
  • Sensory nerves – these conduct the sensory impulses to the brain. The main sensory nerve is the optic nerve. The cranial nerves mentioned above also contain a sensory component which transmits the location of the eyeball to the brain.
  • Autonomic nerves – there are two main types of autonomic nerves:
    • Sympathetic – those concerned with the fight-or-flight response. The radial muscle dilates the pupil in times of stress.
    • Parasympathetic – those concerned with relaxation, which is sometimes called rest-and-digest. The ciliary nerve is the one that innervates the muscle that constricts the pupil. The oculomotor nerve also contains parasympathetic fibres. In fact, it contains the ciliary nerve.

Here is how the information is processed if you see something frightening:

The visual information in transmitted from the back of your eye into the optic nerve (a sensory nerve).
It travels to the basal ganglion of the brain, which is an integrating centre to help you add meaning to what you saw.

From there the information goes to the limbic system, which associates an emotion (such as fear) with it, and also to the visual cortex which allows you to understand what you just saw.

In this case, because fear was involved, the sympathetic nervous system is stimulated to produce a fight-or-flight response. To accomplish that, the main relay station of the brain (the thalamus) sends a message down the spinal cord to the superior cervical ganglion.

This transmits the message to the radial muscle of the iris, which dilates the pupil.
The thalamus also sends other messages to get your body ready for extreme stress.

The iris connection

In the iris, some of the nerve fibres form converging parallel lines that correspond to the pattern of fibres that you can easily see in blue eyes. The fibres converge towards the pupil and spread out as they reach the outer edge of the iris.

So you now have the full picture. The nerves in the iris are connected to the spinal cord, but also to the brain directly. Via this network of nerves encompassing the cranial and spinal nerves and many relay stations and information processing centres (plexes and ganglia), the iris receives word of far-off happenings indicating the tissue state of the body.

Changes in the iris

The research of Walter Lang (Die anatomischen und physiologischen Grundlange der Augendiagnostik) makes the following hypothesis to explain why the iris undergoes specific changes which match pathological changes in the body:

Changes of state are relayed from the thalamus and hypothalamus through the ophthalmic branch of the trigeminal ganglion to the motoneurons of the iris muscle structure. Changes in the impulses conducted by these motor neurons may be responsible for the changes in the muscle structure of the iris, leading to the gradual separation of iris fibres in the stroma and consequent appearance of the lesions and other markings familiar to iridologists.


Let’s look at some examples of iris signs.

This first iris shows a sign called the arcus senilis. This is an indication of poor circulation. Usually the arc starts to appear on the upper part of the iris, which is the area corresponding to the head. This means the circulation to the head is insufficient. People with this sign will often tell you they have difficulty with their memory or concentration.




This iris is a brown iris with cramp rings. Cramp rings look like concentric circles going around the iris, formed by a crimping of the iris fibres. There may be on or more, and they can start at any part of the iris, going around the entire iris or only a portion. This iris has several light gold cramp rings. Cramp rings indicate muscle tension in the body. People with many cramp rings will benefit greatly from a series of massages.



Many people with brown eyes actually have blue eyes with a brown or gold overlay. The brown or gold indicates toxin accumulation in their connective tissue. This is a very common sign, and one that is quite easy to see even without an iriscope. The iris at left is one example of this.





Iridology is a handy tool for natural therapists, since it is non-invasive and provides instant information about the tissue state of the body. A photograph can be taken and later analysed in depth, or saved for comparison with future photographs to track the progress of the treatment.


Tortora GJ, Grabowski SR, 1996. Principles of Anatomy and Physiology. 8th edition. HarperCollins Publishers Inc, New York.
Marcia B K Ph.D., 2000. “Theory and Philosophy of Iridology”. Canadian Neuro-Optic Research Institute [web page online]. Available from: Accessed July 2003.