Some consider the iris the most visually striking part of the eye, with an array of brown, blue, green, hazel, and many shades; aside from eye color, the iris controls light entering the eye by contracting and expanding the pupil. You may have heard that the iris can tell us a wealth of information about our health. In this article, we’ll explore this idea and discuss whether or not iridology is a valid technique for diagnosing medical conditions.
What is Iridology?
Iridology, or iridodiagnosis, is an alternative medicine practice that involves studying the iris to determine information about systemic health and help diagnose medical conditions.
Ignatz von Peczely, a Hungarian physician, developed the idea of iridology in the late 1800s. His iridology chart depicts various parts of the iris representing different body organs, such as the kidney, liver, lungs, and stomach. A naturopathic doctor examines the iris for certain features, including:
- Iris color
- Specks and another pigment in the iris
- Pattern of iris fibers
- Pupil appearance
- Discoloration in the sclera (white part of the eye)
Although many naturopathic doctors use iridology techniques, the current medical evidence doesn’t support purported claims of iridology. Therefore, it’s generally considered a controversial practice. Additionally, the medical industry does not regulate iridology.
In one study of 110 patients, 68 people had a confirmed diagnosis of various types of cancer, while the remaining patients were healthy. Iridology was able to identify the correct diagnosis in only three people. This study and others suggest that iridology is not a reliable method for detecting potentially life-threatening diseases.
What diseases does iridology claim to detect?
Although iridology doesn’t provide a specific diagnosis, it may point to a particular part of the body that isn’t functioning normally and is at risk for certain diseases. Here are several conditions iridology claims to detect:
- Hypertension (high blood pressure) presents as a ring around the iris.
- The liver disease shows up as brown spots in the liver portion of the iris. Some believe that depression may be a manifestation of liver disease.
- Digestive problems may manifest as discolored areas around the pupil and indicate stomach or intestinal issues.
- Inflammation can be an early indicator of many diseases. Depending on the area of the iris affected, a practitioner can pinpoint the part of the body with inflammation.
- A weakened immune system shows up as white marks on the iris. A depressed immune system can make the body vulnerable to infection and other diseases.
Proponents of iridology find the practice a valuable and noninvasive method for the early detection of systemic disease. Although there are no safety risks, others argue that iridology can be dangerous in other ways.
For example, a practitioner may give someone a clean bill of health solely based on iridology. However, that patient may have a serious underlying condition that goes undiagnosed because additional testing was not performed.
Conditions affecting the iris
Although iridology hasn’t proven to be a scientific method of diagnosing medical problems, the iris can still tell us quite a bit about our overall health. Many conditions affect the iris, some of which include:
Arcus senilis is a white or gray ring around the edge of the cornea (the clear covering in front of the eye) and consists of cholesterol deposits. Although arcus occurs in the cornea, it can cause the iris to appear a different color. Arcus is harmless and common in older people or those with a family history of high cholesterol. However, if you develop arcus at a younger age, you could have elevated cholesterol levels.
Iris's freckles and nevus are dark spots on the iris. Like skin freckles, iris freckles consist of a buildup of pigment and are harmless. An iris nevus is similar, except it tends to be larger and extends into deeper layers of the iris.
Iris melanoma is a type of eye cancer that develops in 2% of people with an iris nevus. Although the prognosis is generally better than other eye melanomas, metastases (spreading to other body parts) occur in up to 10% of iris melanomas. Iris melanomas may require treatment with surgery, radiotherapy, or medication.
Iris cysts are benign growths in the iris that can occur after an eye injury, surgery, or for no apparent reason. A bulge in the iris may be visible in some cases. Most iris cysts do not require treatment. However, some iris cysts may require laser or surgical removal if it becomes too large, is painful, obstructs vision, or causes secondary glaucoma.
Iris nodules are associated with various types of uveitis, inflammation of the middle layers of tissues inside the eye (including the iris). Iris nodules and uveitis can develop in people with metastatic infection, sarcoidosis, Vogt-Koyanagi-Harada syndrome, and multiple sclerosis.
Rubeosis iridis is a condition in which new and abnormal blood vessels develop on the iris. Typically, rubeosis iridis occurs in conditions associated with insufficient blood supply, such as diabetes and central retinal vein occlusion (blockage of the main vein in the back of the eye).
The eye is a window to our health in many ways. Although the practice of iridology may have its appeal, evidence-based research doesn’t support the use of iridology in medical practice.
Doss, M., et al. (2022). Iris cysts. Eyewiki.
Ernst, E. (2000). Iridology: Not Useful and Potentially Harmful. Arch Ophthalmol.
Kaliki, S., Shields, C. (2017). Uveal melanoma: relatively rare but deadly cancer. Eye.
Münstedt, K., et al. (2005). Can iridology detect susceptibility to cancer? A prospective case-controlled study. Journal of alternative and complementary medicine.
Myers, T.D., et al. (2002). Diagnosis of Metastatic Infection in Patients Presenting with Uveitis and Iris Nodules. Invest Ophthalmol Vis Sci.