It is believed that the human iris cannot change during the course of a person’s life. The iris forms when the person is still in the uterus, and though there can be some color changes within the iris during the first year of a person’s life, this is generally the only natural change that occurs. Some glaucoma patients get iris variations after treatment, but there are no other changes to the iris, despite illness. This, of course, brings about the question what is the iridologist looking at if a person’s eye never changes?
Iridologists and proponents of iridology generally feel that the problems a person has, particularly illnesses, can be determines by whatever variations are visible in the iris. They do not necessarily look for changes in the iris. However, it can also be argued that if the iridologist is not looking for changes, he is not able to diagnose any illnesses at all.