A little Saturday morning nonsense: iridology and sclerology?

Somehow, I found myself looking at iridology diagrams. Iridologists claim that the surface of the iris is connected to every organ in the body, so the detailed pattern of flecks and lines and spots in the colored portion of your eye is a map to your health, as good as an X-ray or MRI. They actually do get quite specific.


From there I stumbled onto sclerology — these sclerologists claim the map is in the whites of your eyes, and that the network of blood vessels, for instance, tells you all you need to know about the state of your body.


Why, just this morning, I got up, looked in the mirror at my rheumy bloodshot eyes, and learned instantly that I was a walking tumorous mass that apparently was simultaneously exploded and crushed in a tragic farm machinery accident yesterday. It was terrible.

But this is just patent bullshit, every bit of it.

For one, we’ve taken eyes apart and looked. There is no connection between eyes and every other organ; the iris is innervated via the ciliary ganglion (the parasympathetic pathway) and the superior cervical ganglion (sympathetic). There are patterns to the capillaries of the eye, but they are more for efficient circulation of the blood than reflecting a mystical connection to your pancreas.

These maps owe more than a little to the model of the cerebral homunculus, which shows the targets of innervation by the sensorimotor cortex. That makes sense. There are necessary connections that the brain makes to control or receive input from the periphery. There are no such necessary associations with the eye. Also, those maps were made with thorough experimental and observational analyses of thousands and thousands of people — functional deficits were mapped to stroke lesions, and focal stimulation of brain regions were found to lead to specific sensory and motor responses. We’ve got data to back up the idea of how brains are connected to body parts.

And then there’s the plagiarism: why are the sclera and iris maps so similar, with bowels below and brain above, and heart central lateral and lungs central medial? It looks like someone invented a pattern for one part of the eye, and then a copy cat con artist stole it and redrew it for another part of the eye. And look at the pretense of precision! Do you believe the pituitary is associated with some specific point at about 11:30, while the ego is found at 11:10?

I confess, my ego compelled me to go look in a mirror for my ego. Couldn’t find it. My ego is just shattered now.

It’s still impressive in a pseudoscientific way. None of these maps are constructed by scientific methods — carefully replication of meticulous empiricism — and are totally lacking in any kind of observational foundation. You can just sit down and make stuff up, and if it’s flashy enough and apes the lingo of real scientists, someone will believe it enough that they’ll pay real money to a quack.


  1. chigau (違う) says

    When these maps meet the reflexology maps, is there a feedback loop?

  2. Rich Woods says

    Pah, eyes are nothing. Ears have a fetus within them.

    I like the way they claim that the heat from smoking makes it harder to stop smoking. Does the ice in my glass of whiskey conversely make it easier to stop drinking?

    You also have to note the quack miranda in the footer. It’s almost like they know they’re talking shit.

  3. Ed Seedhouse says

    I do like the idea of having an extra brain in each eye, but the extra penises probably won’t get much use.

  4. Ed Seedhouse says

    P.Z., I see you replied to me at 11:54 a.m. to my post timestamped 10:53 a.m. but my infallible “atomic” clock says it’s only 09:00 as I write. Apparently Pharyngula is a time machine! Wait, give me back my three hours!!

  5. zetopan says

    It does not help that ultra-credulous news reporters and the press peddle iridology as “scientific” and even claim that it is used by Harvard Medical school. Years ago I watched Tracy “bubble head” Barry (a TV news anchor who may even believe in the Tooth Fairy) “interview” an idiot iridologist on TV and not question a single ridiculous claim that he made, including the Harvard Medical school nonsense. A credulous scientific illiterate press is part of the reason why the US is now being run by so many anti-science flakes.

  6. wzrd1 says

    The worst one I’ve heard of being peddled actively is homunculus models for acupuncture, both in the VA and “battlefield acupuncture”, with the homunculus being parts of a wounded service member’s ears.
    What is astonishing is how many physicians who are embracing that nonsense!

  7. vucodlak says

    @ wzrd1, comment #10

    Peddling homunculi!?! But the formulae for homunculi has been ‘lost’ for generations, and with good reason. They’re hardly the sort of thing people should be able to purchase from the valise of a vagabond salesperson. Or order from the back of a comic book. Wherever one purchases arcane curiosities, these days.

    I mean, the damn things are almost always homicidal, not to mention unstable. The Frankenstein incident was a fluke; usually the vicious buggers try to tear you apart from the word ‘go,’ and get themselves worked up into such a froth that they explode. Suddenly, messily, and all over the place. Considering the reagents involved in their creation, this is hardly ide…

    Oh, homunculus models. Erm, sorry about that. Carry on.

  8. Crudely Wrott says

    Why, I had no idea that my irises were so smart.
    All the little bumps on my head are suddenly rearranging themselves in a frantic effort to comprehend this new paradigm.
    Finally, I have a use for that illuminated magnifying mirror I found at a garage sale.
    Thanks, PZ. I’m a better, and better functioning, human now.

  9. wzrd1 says

    @vucodlak #11, see Orac’s blog at Respectful Insolence for more details and the idiotic maps being promulgated for “Battlefield Acupuncture”.
    I’d have lost two grades of rank had that physician tried to ply that crap when I was over in the sandbox.

    Little angers me more than when someone tries to introduce idiotic crap that would harm one of our soldiers! Had a National Guard medic come by, trying to ply reiki. That got stepped on hard, once I learned what his BS was about.

    Yeah, there is an energy metabolism, it involves, for animals, glucose, oxygen and water, for the most part.
    Human photosynthesis is real as well, vitamin D is *really* cool. Somewhat recently, I learned of some immune effects that can massively (read: an increase of a “massive 12%”) increase immune function against pathogenic viral infection with proper levels of vitamin D (somewhat deficient in northern latitudes).
    So, I supplement by hanging my arm out of the car window while driving in spring and summer, retrieve mail without my shirt (I’m a guy, so it’s legal in states that fear female nipples, of which I currently live in (well, they *are* dangerous, they might feed a hungry child of that woman. Children are to be born, not fed, if the mother is poor)) and go outside as often as possible in shorts (laughable, as I have, other than the shirtless tan, a farmer’s tan on my legs) and garden.

    Note the sarcastic notes to idiotic views, very real science news that I eagerly await replication on and surprise at a 12% increase in immune response, which makes me almost mistrust, but hope for that modicum of success in a “boost”, but laughing at the level of “success”.

    I do have a sense of humor though, it’s best experienced firsthand, when I’ll say something horrific, seemingly serious, while my face displays the polar opposite. Doesn’t do well online, where my face would simply cause monitors to freeze.

    Example: In real life, a recent Quora question was asked about killing terrorists families. My personal answer would be a request for information on precisely how to kill an infant and avoid the negative publicity, suggesting flamethrowers, giant ovens inside of detainment camps, etc. With a horrified, loathing expression on my face. Couldn’t do that in a text forum, so I attacked it on Article 3, Section 3 grounds, history, being civilized and providing aid and comfort to the enemy.
    Thanks all here for that help. Previously, I’d have gaffed. Badly, beyond Poe’s Law gaffe.
    See some responses here for examples.
    What I honestly wanted to do, when seeing that Question was, well, vomit.

  10. blf says

    The mildly deranged penguin has just scientifically discovered, by means of a carefully consumed large barrel of brandy, that snot from the left nostril, after being processed by commercially-secret patent-pending method known to include being fed to a blue whale, is a prefect predictor of, well, something — she hasn’t quite deduced what yet, and has gone off to fetch another barrel for more experiments — and plans to begin selling “it”, whatever “it” is, via a worldwide franchise of licensed websites featuring delivery by USB, Bluetooth, and, for those in a hurry and at a premium price, cuddly walrus. This, she predicts, will rapidly put the iridologiers and sclerologists out of business, since it’s even more stupid.

  11. says

    In the late ’70s, I was so sick with stomach problems. The doctors had me so doped up with pills that I couldnt get out of bed. Thier last step was to take part of my colon.
    I was given the name of an M.D. who also practiced irodology. Durning my appointment there was no prior medical history taken. When the Dr. Examined my iris, he was am to tell me past injuries and illnesses. He changed my diet, took me off all pills, started me on supplements and different teas. Within thirty days, I was pain free and have had only 1 attack since then. Im a total believer!

  12. says

    Type 1 diabetic here. There is indeed a real diagnostic relationship between a part of the eye and the health of other major organs. But it’s not the iris, it’s the retina.

    The fine capillaries of the retina can be digitally photographed with astonishing resolution, particularly if they inject you with contrast dye. Trouble seen there is the proverbial canary in the coal mine for a cascade of typical diabetic circulatory complications, and an indicator of kidney health, for example. Not to mention blindness.

    But there is no retina “map.” FFS.

    I go every 3-4 months for scans. And that has NOTHING WHATSOEVER to do with the fact that my ophthalmologist is a hottie, I tells ya.