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Cephalopod precursors evolved eyes and then brains developed from the eye so their eye is structured correctly.

Vertebrate precursors evolved the brian first and the eye evolved out the brain as a sensory stub. So it’s upside down and inside out like in picture.

The nerve cluster goes through the back of the eye splits and folds back to end in light receptors. Light hase to go through the nerves before hitting the sensor.

There is even a reflective layer after the sensors that gives the sensors a second chance at picking up the light. This is what causes the red eye or green eye you sometimes see in flash photography.

It would require a genetic rebuild to fix this and the intermediate steps evolution usually use would be so disadvantageous they are selected against. So the right combo of mutations to give us a working octopus eye is VERY unlikely to happen.

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ArmchairAce1944@discuss.online ⁨2⁩ ⁨days⁩ ago
Hypothetically, if we managed to make a genetically modified human with the eye that you are talking about, what advantages/disadvantages would it have over our current eyes?

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- squaresinger@lemmy.world ⁨2⁩ ⁨days⁩ ago
  No blind spot and probably better light sensitivity. But it’s not like we really need higher light sensitivity as land-dwellers.
  
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  - nymnympseudonym@lemmy.world ⁨2⁩ ⁨days⁩ ago
    
    better light sensitivity
    
    I like to think of it as “colors and light so brilliant and pretty it’s like tripping shrooms”
    
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  - Quadhammer@lemmy.world ⁨2⁩ ⁨days⁩ ago
    It says vertebrae wouldn’t that include cats who have insanely utilitarian eyes
    
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    squaresinger@lemmy.world ⁨2⁩ ⁨days⁩ ago
    It does, but their eyes still have blind spots and their eyes could possibly be even better if their photoreceptors were oriented towards the incoming light.
    
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- Semjaza@lemmynsfw.com ⁨1⁩ ⁨day⁩ ago
  No red eye in photos!
  
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Tattorack@lemmy.world ⁨2⁩ ⁨days⁩ ago
Hypothetically, what would be the advantages of “correcting” this evolutionary mistake in humans?

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- captainlezbian@lemmy.world ⁨2⁩ ⁨days⁩ ago
  Bragging rights
  
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- scratchee@feddit.uk ⁨2⁩ ⁨days⁩ ago
  I believe no blind spot, which is the place where all the nerves bundle together and pass through the sensing layer, leaving a hole in our vision (the brain works hard to hide this hole from our perception, but it’s still there and can cause accidents) Also maybe better vision in general?
  
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- Hugin@lemmy.world ⁨2⁩ ⁨days⁩ ago
  No blind spot and better light detection. The light having to pass through the nerves causes a lot to be lost.
  
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prole@lemmy.blahaj.zone ⁨2⁩ ⁨days⁩ ago
Is this at all related to why the part of the brain that does visual processioning is way in the back?

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- Hugin@lemmy.world ⁨1⁩ ⁨day⁩ ago
  Not a dumb question. I think it’s because the Occipital lobe is an evolutionary old part of the brain. It’s right on top of the brain stem the oldest part.
  
  The newer parts developed between the eyes and the older parts of the brain. Pushing the eyes forward. That’s my understanding but I might be wrong.
  
  Hopefully if I am wrong someone jumps in and provides a correction.
  
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- Valmond@lemmy.world ⁨1⁩ ⁨day⁩ ago
  It’s not in the back IIRC, but the nerves go all the way back and enters the brain there.
  
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