Iridology is generally a non-invasive technique. However, it may pose a danger if it is used for disease diagnosis instead of more proven approaches. Incorrect diagnoses have been reported using this method and can potentially lead to inappropriate treatment or to psychological stress in patients. In addition, serious medical problems may go undiagnosed. Iridology is therefore not recommended as a sole method of diagnosis or treatment for any condition.

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Hypertension (diagnosis) (Grade: C)
Preliminary studies suggest that iridology may assist in the identification of individual predispositions for vascular diseases such as hypertension (high blood pressure). Further research is needed to confirm these findings.

Cancer (diagnosis) (Grade: D)
There is currently limited available data supporting iridology as a diagnostic tool in cancer. Additional study is needed.

Gallbladder disease (diagnosis) (Grade: D)
Preliminary study examined the ability of iridologists to diagnose gallbladder disease from slide photographs of patients with the disease and found no evidence of agreement or diagnostic accuracy. There is no evidence supporting iridology as a diagnostic tool in gallbladder disease.

Kidney disease (diagnosis) (Grade: D)
Preliminary study submitted photographs of irises of kidney disease patients to practicing iridologists and found no evidence of accurate detection of kidney disease. There is no evidence supporting iridology as a diagnostic tool in kidney disease.