It is not a treatment but a way of diagnosing the causes of illness or imbalance. Diagnosis is made by analysing the markings on the irises of the eyes, iridologists claiming that different areas of the iris correspond to different parts of the body. Iridologists can also identify ten different types of constitution by looking for delicate patterns in the iris. Treatment is suggested according to these findings and also warning signs of later problems can be heeded.
Many holistic therapists use iridology in their diagnoses.