A Christian Perspective By Janice Lyons, RN, MAEd About the Author Iridology is defined by proponents as a study of the iris of the eye to detect weakness or illness in specific body tissues. Based on that assessment diet and herbs are used for treatment. Areas which can be assessed include physical, mental, sexual, and emotional. The descriptions of the anatomy and physiology of the iris-body connection vary from text to text.
Most texts claim that the optic nerve carries impulses from all over the body to the iris.
However, a survey of scientifically reputable literature shows there is no connection between the iris and optic nerve. There is no evidence suggesting that any fibers from the optic nerve make connections with the iris. Some iridologists claim that the connection from the nervous system occurs through the autonomic system. Even here there is disagreement, as some claim it is the sympathetic, while others opt for both sympathetic and parasympathetic connections. Anatomically the tissue of the eye as a whole developed from the same embryonic neural tube which is also the source of the brain developmentally.