It is known that the human eye anatomy makes it so that all images we see with our eyes are flipped upside down. Without noticing it, at an early age, the brain is adjusted to this. What I mean is that we at an adult stage don't walk around troubled with everything we see being upside down, even though this is the technical reality.

My question is that I remember hearing somewhere that if a person, at a later age (adult), were to start wearing glasses that flipped everything back around (so that the eyes now captures the image of how the reality actually looks in our mind) that person would eventually after some time be totally adjusted. The person would eventually see no difference between how his vision worked before he started wearing the glasses compared to how it works now after.

Is this feasible?

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    The technical reality is that the orientation of the image on the retina is completely irrelevant. It's as irrelevant as, for example, the orientation of the DRAM chips that store the video frame buffer on your computer's motherboard.
    – Kaz
    Dec 11, 2012 at 2:30
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    @Kaz: you are right, but as it turns out it was part of the inspiration for the experiment.
    – Oddthinking
    Dec 11, 2012 at 3:04
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    @Kaz Just because you don't find it relevant doesn't mean that it isn't. As Odd said, that's what triggered the experiment. As long as people ponder a notion, it's relevant. You're welcome. Dec 11, 2012 at 8:32

3 Answers 3



You are referring to a classic experiment in Perceptual Adaptation from 1896:

Here's a video from a BBC documentary reproducing the experiment. You can also check this book as it might contain other examples.

There have been more advanced experiments, such as

These days, the inversion goggles are easily available - I found several examples on Amazon, Ebay and Etsy by searching for that term.


TLDR : Yes. A person wearing glasses that inverted the vision would in a few days adapt and perceive the vision as normal.

George M. Stratton, a psychologist, was intrigued by the idea of perceptual adaptation. Because the retina receives images upside down, he was intrigued to see what happens when the brain receives an image that is right side up. Stratton conducted experiments in the 1890s, in which he tested the theory of perceptual adaptation. In one experiment, which Stratton conducted, he wore a reversing telescope for 21½ hours over three days. To his disappointment, his vision was unchanged. After removing the glasses, "normal vision was restored instantaneously and without any disturbance in the natural appearance or position of objects." Determined to find results, Stratton wore the telescoping glasses for eight days straight. By day four, his vision was upright (not inverted). However on day five, images appeared upright until he concentrated on them; then they became inverted again. By having to concentrate on his vision to turn it upside down again, especially when he knew images were hitting his retinas in the opposite orientation as normal, Stratton deduced his brain had reprocessed his vision and adapted to the changes in vision.


Perceptual adaptation is an element that has been researched extensively by George Stratton. All of his experiments failed to falsify the theory of perceptual adaptation. Perceptual adaptation is a theory that proposes the notion that our brain and senses collaborate. Our vision can be altered, but our brain corrects this alteration to seem correct. Our brain allows us to live a normal life with an altered perception of a normal life

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    Wow! It only took five days?! That's incredible. Thanks for your answer. Dec 10, 2012 at 14:02
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    Smarter Everyday even tried someone adapting to a "reverse bicycle", where the steering has gears that reverses the direction that the tires turn. His son adapted much faster than he did, but after couple months, he did it. Then he realize he couldn't ride a normal bike anymore, and took about 5 minutes to readjust back to a bicycle.
    – Nelson
    Aug 24, 2021 at 2:58

Yes, but partial-rotations have more severe effects when transitioning between one perceptual mode and the other.

See this wonderful exposition by Steve Mann who spent many years immersed in a virtualized perceptual environment. He found that using a 90 degree rotation of the visual field eased transition from normal vision into the apparatus-space.

Pic of Mann on the left of a group photo in this page

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