I used to have a loose business affiliation and share office space with a "nutritionist" who determined her patients' dietary deficiencies using iridology (examining their eyes). She had a forceful personality and sold massive amounts of supplements, and I've always felt a little guilty about the revenue she brought in. It's now been a number of years since we parted ways, but I've really suspected she was just a well-practiced bullshitter. Am I correct believing that iridology is a complete and total farce?
--Name withheld because "she still scares me a little"
It may not lessen your guilt to know that you are right; studying the colored part of the eye (the iris) has absolutely no scientific validity as an indicator of nutritional deficiencies. A close examination of the iris is, however, an important factor in determining whether one should order digital double-prints from the Kodak EasyShare Gallery. An acute case of red-eye may necessitate immediate treatment with heavy doses of vitamin P (Photoshopia steadyhands). If your nutritionist wasn't selling that, the remorse should be hers alone.
Though some claim iridology to be older, its use for medical diagnosis originated in the late 1800s with a Hungarian physician having the perfectly comic name of Ignatz von Peczely. The story goes that, as a child, young Ignatz noticed a black streak in the eye of an owl whose leg he had accidentally broken. Later, as a physician, he saw the same mark in the eye of a man with a similarly broken leg (remaining unexplored is von Peczely's serial leg-breaking). Ultimately, based on little more than guesswork, he devised the first diagnostic chart of the iris. Years later, others refined his map so that today each organ has a location, like spokes on a wheel, easily identified by referencing a clock face. For example, the left lung corresponds to an area in the left iris at about 2:30, spleen at 4:15 and vagina, "Say, around 7ish?"
Iridologists look for flecks, streaks or other markings in the iris, and using the map, conclude that problems are present in the associated organ. Lighter colors of these specks are supposedly indicative of more activity or sensation (i.e. pain) and the darker ones mean chronic problems or possibly dying tissue. Their pseudoscientific explanation: "In these exact locations lie exposed nerve endings directly connected to each organ, making clearly visible expressions of disease, toxicity or genetic weakness." My witty comeback: "You're so full of it, your eyes are brown." Weird how that childish retort becomes unintentionally supportive, isn't it?
Researchers apparently have concluded the same as me, albeit in a slightly more mature fashion. Nearly 30 years ago, the Journal of the American Medical Association published results of a test in which three experienced iridologists (including the foremost authority in the field, Bernard Jensen) were challenged to identify which of 143 patients suffered a confirmed kidney disease--using only eye photographs. Not only did they fail miserably, but the sleuths did not even agree among themselves. Then in 1988, five Dutch iridologists were similarly challenged with iris photographs of a different set of patients, half of these having severe gallbladder disease. The results were similarly underwhelming. And to ice the cake, just two years ago, there came another objective test and another abject failure: 110 patients, 68 with cancer, three correct matches.
Given the facts that the iris is essentially unchanging and the "exposed nerve ending" theory is proven nonsense, why do truly sincere iridologists swear they can see changes over time? The answer may lie in the iris's microanatomy. What appears to be a flat surface is really a three-dimensional array of pigment cells (and others) in loose connective tissue. Thus, a tiny change in angle or intensity of light--even between photographs--will cast shadows and false images across a craggy background. This, coupled with vague, leading questions and a hopeful client's feedback, creates a situation not unlike a psychic reading. In this case, however, it seems both parties are being duped.
The majority of iridologists, I would guess, believe they're honestly providing benefit--and they could likely provide multiple testimonials from happy clients. Nevertheless, a few satisfied customers cannot outweigh the needless worry and real medical expense resulting from what is, in effect, a randomly chosen diagnosis. But another scenario is even more dangerous: A symptom explained away by iridology can lead to a deadly serious delay in accurate diagnosis and treatment. Therefore, I would strongly advise against the counsel of iridologists and suggest to them that their talents may be put to better use elsewhere. It's almost summer, and the photo kiosk in the mall is always looking for help.