The Astounding Magnetic Sensor in the Human Eye

“Yeah, b—h! Magnets! Oh!” —Jesse Pinkman, Breaking Bad

In A Nutshell

Birds, sea turtles, bats, and an assortment of other animals have the ability to navigate by sensing the Earth’s magnetic field, yet it’s long been assumed humans are devoid of this skill—after all, we do have an ungainly habit of getting lost in the woods. However, researchers have recently discovered that humans have the same magnetic-sensing protein in our eyes that’s found in all types of other animals. How, exactly, we’re using that protein is still unclear.

The Whole Bushel

Animals sense magnetic fields in a variety of ways and one of those ways is by using an eye protein called cryptochrome, which uses light to detect the tiniest of geomagnetic differences. Migratory birds, fruit flies, and butterflies are known to rely on this protein to accurately get where they’re going, and, surprisingly, the human eye contains cryptochrome too. Of course, this raises the question: If we have magnetic sensors in our eyes, why are we buying pricey GPS navigators and still managing to get hopelessly turned around? Well, it turns out, scientists aren’t entirely sure.

What we do know is that if you “knock out” a fruit fly’s magnetic sensing gene and then replace it with human cryptochrome, the fruit fly’s geomagnetic vision is restored. Scientist Steven M. Reppert and his colleagues discovered this after first swapping cryptochrome in monarch butterflies and fruit flies. Being able to seamlessly switch the fruit fly cryptochrome for the butterfly version let the researchers know that both animals were using the protein for the same purpose—magnetic navigation. Then, after noticing the remarkable DNA similarities between monarch and human cryptochromes, they decided to see if the eye protein from people would also work in the fruit flies. And it did.

Reppert’s findings don’t prove we have some kind of latent or unknown magnetic sense, but he did conclude his study by saying, “A reassessment of human magnetosensitivity may be in order.”

Before Reppert’s work, no one had done any significant research in human magnetoreception since the 1980s when Dr. Robin Baker of the University of Manchester performed a series of experiments suggesting people can indirectly sense magnetic fields. In his experiments, he would get blindfolded volunteers, take them on long, convoluted journeys, and then ask them to point their way back home. He performed the study on thousands of participants and found that most people could point in the correct direction. The only time their accuracy dropped was when they wore magnets on their heads. Unfortunately, no one other than Baker has been able to repeat his study and get the same results. Consequently, Baker’s human magnetoreception findings were heavily ridiculed, and he eventually moved on to other research. The new information about cryptochromes, however, is causing some to give Baker’s work another look.

Previously, it was thought people used cryptochromes strictly for maintaining our bodies’ circadian rhythms, yet now some are wondering if it might also work as an optical compass. Perhaps we are better navigators than we thought but aren’t utilizing our full capabilities. Or maybe, a long, long time ago humans did use geomagnetic orientation and somehow lost the skill through evolution, or our modern, electromagnetic world is blocking our abilities. The most likely and commonly accepted explanation is that humans might simply use cryptochrome in a different way than fruit flies and butterflies. Maybe so, but that common sense hypothesis won’t stop us from trying to unleash our Magneto-like superpowers.

Show Me The Proof

Discover: Humans have a magnetic sensor in our eyes, but can we detect magnetic fields?
NY Times: Magnetic Field Sensed by Gene, Study Shows

  • AdalineBrashier

    which type of sensor fitted in the Human eye?when the sensor is fitted in the Human eye even Human is feels different .

  • percynjpn

    My eyes must be missing them – I get lost in my own yard.

  • oouchan

    Yeah…not me. Put me on a freeway/highway and I will find where I’m going with my eyes shut. Put me in parking lot and I can’t find the exit. How dumb is that?

    Cool info.

    • i can never remember where i parked my car in the multi story parks, i put it down to alcohol abuse

  • I can get lost in an empty square room with one door.

  • Lisa 39

    I never get lost, I take the scenic route!

    • Clyde Barrow

      …and then you ask for directions.

      • Lisa 39

        Pfft, that takes the fun out of it! My magnetic eye thingy usually gets me back on track. I have asked for directions twice, both were out of state and before I had a snazzy cellphone with maps and directions!

        • Clyde Barrow

          I could be lost in the middle of the Gobi Desert and still manage to find a drinking establishment.

          Of course Bonnie will insist I ask for directions….

          • Lisa 39

            Yay for drinking establishments with alco beverages! In the middle of a desert!

            I’m surprised that Bonnie would do that, I would think with her sense of adventure she wouldn’t be a typical woman about asking for directions. ( please don’t tell her I said that, I don’t want to get my ass kicked or get shot 😉 )

    • good attitude

  • edzyl blane

    i love the quote

  • EmilieSeltzer

    It will be good sensor fitted in the human eye.

  • Samuel Auditama

    LOOK AT M!! I HAZ MAGNETIC COMPASS IN MAI EYES! im still not sure thou about all this and where it is leading to, but its interesting to know more stuff about yourself. Maybe there will be some awesome technological breakthrough on this, lol what am i saying, of course there will be, i just hope it would come out soon.

  • Iminurbase

    My eyes can see the magnetic attraction between people, but my brain cannot replicate the action…. Forever Alone