If the image formed on a retina is inverted, then why do we see things upright?
Vision is an amazing sense and it takes a lot of different steps to allow us to see what we see. First, let’s talk about why the image in the retina is inverted in the first place. The eyes work as lenses and light must pass through a very tiny hole (the pupil) and make it to the retina. By inverting the picture the eyes allow us to see images that are way bigger than the size of the pupil. Thus the part we consider as “up” crosses to the bottom and the part we consider as “down” crosses to the top (use the picture bellow as guide). Our brains, though, are amazing organs and know the image has been inverted; they flip it back so that we can experience the world the right way. At the same time the brain is processing this upside-down image, it is also putting together information from both eyes so that we can have one complete picture instead of two parts. Vision involves many different parts of the brain, including the optic nerve, the corpus callosum, and the occipital lobe.