Have you ever wondered what it would be like to see the world upside-down? The funny thing is, technically, you already do. When you look at something like a book or a tree, that “image” is projected onto your retinas upside-down and reversed, as a camera lens performs. It’s when the “image” is processed by your brain that it is flipped and turn around, allowing us to see the world correctly.
Now, you may have noticed that there are quotations around the word “image.” That’s because the “images” in your brains are not in fact pictures but collections of neural activations. However, without the brain we would not be able to process the “images” around us. These neural activations are relayed to the visual cortex of the brain, where “images” are reinterpreted. However, say you are upside-down, because of perceptual adaptation our brain will account for any differences in our visual field and allow us to perceive our vision as “normal.”
Numerous experiments have utilized forms of inversion glasses to test the capability of our brains to flip our visual field through perceptual adaptation, going as far back as the 1890s when American psychologist George M. Stratton wore a reversing telescope for eight straight days. One current example of inversion glasses is the Reversing Goggles, which has one plexiglass prisms for each eye. In its standard configuration, the prisms will cause you to see the world upside-down, but if you rotate the prisms ninety degrees, you will see everything reversed from left to right. At first when wearing the goggles you will feel disoriented, but, because of perceptual adaptation, eventually you will be able to orient yourself and accomplish simple tasks like walking and grabbing objects. Some studies have even shown subjects who have been able to ride a bicycle after their brain adapted to the world being upside-down.
So while you can very well attempt to see the world upside-down, because of perceptual adaptation this altered perception will eventually feel normal.