If someone gazes searchingly into your eyes, then says you have a sluggish intestine or inflammation of some vital organ, chances are they have been practising iridology, a diagnostic system that aims to assess the condition of the body by analysing the iris.

Hippocrates and Philostratus used it and, as long ago as 1000 BC, the Chaldeans of Babylonia left records of iris charts on stone slabs. But the father of modern iridology was Ignatz von Peczely, a Hungarian doctor who became intrigued by the subject as a boy, after he saw a black mark appear on the iris of an owl whose leg he had accidentally broken while trying to capture it. Convinced he was on to something, he researched the subject for years and published his findings in 1880. Today, though, iridologists tend to use a chart developed in 1950 by an American physician, Bernard Jensen.

The theory is that the thousands of nerve-endings in the iris are connected, through the brain and nervous system, to every tissue of the body. The left side of the body is represented by the left iris, the right side by the right iris, and organs in the centre or both sides of the body in both eyes.

The patterns, structures, colours and degrees of light and dark reveal whether an area of the body is strong or weak and whether there is injury, irritation or degeneration. Thus, by superimposing an iris chart (a kind of “body map”) over a projection of the iris, the iridologist can “see” what is going on inside the body.

Iridology does not purport to pinpoint what is wrong with you, but does claim to be able to indicate which area of your body has a problem. What’s more, practitioners claim, it can spot signs of trouble long before symptoms appear.

The best time to consult an iridologist, apparently, is when you are not ill but feel you are not quite well. Afterwards the iridologist may refer you to a complementary therapist or pack you off to your GP with a recommendation to get, say, your liver checked out.

International Association of Clinical Iridologists, Orchard Villa, Porters Park Drive, Shenely, Radlett, Herts WD7 9DS. Tel: 01923 856222