iridology

According to Wikipedia, Iridology, also known as iridodiagnosis, is an alternative medicine practice in which patterns, colors, and other characteristics of the iris are examined for information about a patient's systemic health. Practitioners match their observations to iris charts which divide the iris into zones that correpsond to specific parts of the human body. The eye, therefore, acts as a "window" into the body's state of health. Iridology is a practice that is not recognized by mainstream medicine.

Iridologists highlight systems and organs in the body that are healthy and those which are described as overactive, inflamed, or distressed. These may point to a tendency in the patient towards certain illnesses, to reflect past medical problems, or to predict health problems which may be developing.

Since iridology is not a method of treatment, its practitioners have often studied other branches of alternative medicine.