Why do our brains flip what we see?


i’ve heard that because of the way light works, our eyes actually perceive images upside down and our brain works to correct this.

but why does our brain even do this? why not just make the flipped image the normal way we see? if we grow up with ‘upside down’ vision, wouldn’t we just adapt like those born with abnormal senses? shouldn’t leaving visuals undoctored just cut out some unnecessary work for our brain?

In: Biology

You’re both right. The flipping is a consequence of your eye’s lens refracting the light and it being projected past the point where refraction hits its zero scale. The brain interprets this signal pretty directly, there aren’t neurons “flipping” anything, but your brain is interpreting an image where down is basically up.

Experiment has shown that if you pre-reverse the image using glasses, [the brain adjusts in a handful of days](https://www.theguardian.com/education/2012/nov/12/improbable-research-seeing-upside-down). It even works with a mirror image where left and right are reversed.

It thus shows the brain can handle whatever image — flipped or not — that’s thrown at it, and mentally maps what’s physically low-right to the lowest and rightmost part of the image we end up “seeing”.

So that flipping is not hardwired, it’s just an interpretation of our brain; just like hearing something louder in your right ear makes you interpret the sound source from coming from your right, and if you flipped your ears you’d eventually adjust and perceive a louder sound in your left ear as coming from the right.

So your confusion comes because you are imagining, perhaps unwittingly, a place in the brain where everything “comes back together” after the photons are converted to nerve impulses in the eye. If that was the case then you would need to flip the image, like you imagine.