The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light. But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness!
Iridology (also known as iridodiagnosis or iridiagnosi is an alternative medicine technique whose proponents claim that patterns, colors, and other characteristics of the iris can be examined to determine information about a patient's systemic health. Practitioners match their observations to iris charts, which divide the iris into zones that correspond to specific parts of the human body. Iridologists see the eyes as "windows" into the body's state of health.
Iridologists use the charts to distinguish between healthy systems and organs in the body and those that are overactive, inflamed, or distressed. Iridologists believe this information demonstrates a patient's susceptibility towards certain illnesses, reflects past medical problems, or predicts later health problems.
As opposed to evidence-based medicine, Iridology is not supported by quality research studies and is widely considered pseudoscience. Iris texture is a phenotypical feature which develops during gestation and remains unchanged after birth. The stability of iris structures is the foundation of the biometric technology which uses iris recognition for identification purposes.