5 ms·

That's just nature making the best it can of a historical accident. If you were designing the eye from scratch, you'd have the nerves coming out the back like

That's just nature making the best it can of a historical accident. If you were designing the eye from scratch, you'd have the nerves coming out the back like in squid. Then if you wanted something that concentrates the red and green wavelengths, you could put something else in front of the light sensing cells. You'd end up exactly where you are now, except you'd not have a huge blind spot, and wouldn't have to spend as much brain power compensating for it.

dekhn 11y ago
The blind spot is not huge. It's easily compensated for, and it appears the mammalian eye has other attributes that make it work well. We just don't have enough data to understand whether mammalian eyes embedded a major problem that had to be compensated for, or if this design has attributes that make it desirable.
- protonfish 11y ago
  Maybe, but either vertebrates or cephalopods have to have sub optimal design. My money is on the backwards retina being the kludge.
  - dekhn 11y ago
    No, neither is required to have a suboptimal design. Why do you think that? Mammals are quite successful.
    - mikeash 11y ago
      They can't both be optimal. The probability that both are exactly equally good is so remote as to be ignorable. Successful does not imply "no flaws." It's interesting to see this argument brought up in the context of biology. It's frequently applied to software, for example it shows up in basically every discussion of PHP.
      - breischl 11y ago
        >>They can't both be optimal. They could both be optimal for their respective uses. Humans don't spend a lot of time on the seafloor, and cephalopods don't spend a lot of time in the open air. Certainly there are other tradeoffs to be made as well.
- ghostberry 11y ago
  It's 7.5° high and 5.5° wide. If you don't consider that huge, then that's up to you. But for me, that counts as huge, especially since it's fairly near the middle of vision. That's over half the width of my hand at arms length.
  - dekhn 11y ago
    So... this makes a difference in your daily life as a nomad hunter or software engineer how? None at all. You just don't perceive it unless you go out of your way to.
    - juliangregorian 11y ago
      The way you're carrying on it's almost like you were the project manager who delivered the blind spot. It's a feature, not a bug. ;)

dekhn 11y ago

The blind spot is not huge. It's easily compensated for, and it appears the mammalian eye has other attributes that make it work well. We just don't have enough data to understand whether mammalian eyes embedded a major problem that had to be compensated for, or if this design has attributes that make it desirable.

protonfish 11y ago
Maybe, but either vertebrates or cephalopods have to have sub optimal design. My money is on the backwards retina being the kludge.
- dekhn 11y ago
  No, neither is required to have a suboptimal design. Why do you think that? Mammals are quite successful.
  - mikeash 11y ago
    They can't both be optimal. The probability that both are exactly equally good is so remote as to be ignorable. Successful does not imply "no flaws." It's interesting to see this argument brought up in the context of biology. It's frequently applied to software, for example it shows up in basically every discussion of PHP.
    - breischl 11y ago
      >>They can't both be optimal. They could both be optimal for their respective uses. Humans don't spend a lot of time on the seafloor, and cephalopods don't spend a lot of time in the open air. Certainly there are other tradeoffs to be made as well.
ghostberry 11y ago
It's 7.5° high and 5.5° wide. If you don't consider that huge, then that's up to you. But for me, that counts as huge, especially since it's fairly near the middle of vision. That's over half the width of my hand at arms length.
- dekhn 11y ago
  So... this makes a difference in your daily life as a nomad hunter or software engineer how? None at all. You just don't perceive it unless you go out of your way to.
  - juliangregorian 11y ago
    The way you're carrying on it's almost like you were the project manager who delivered the blind spot. It's a feature, not a bug. ;)