I've often noticed that on stretching my eyes to the side I see a lot better. On searching, I read that this happens because the cornea reshapes itself (due to the ciliary muscles). But is that all, or is there a more accurate biological explanation for this?

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    $\begingroup$ It is indeed because you're distorting the cornea. I don't think the ciliary muscles are involved (source?) Also, it depends on your vision. Some people with perfect vision will see less perfectly. $\endgroup$ Aug 3, 2017 at 15:26
  • $\begingroup$ You might get pinhole effects in some circumstances, but for me this technique just makes my vision much much worse (and certainly wouldn't be the best way to introduce a pinhole). $\endgroup$
    – Bryan Krause
    Aug 3, 2017 at 19:31
  • $\begingroup$ @BryanKrause - Although changing the transmission of lightwaves is altered in both pulling the eyelid and looking through a pinhole, the mechanisms are very different. Pulling your eyelid is akin to squinting in the effect it has on the cornea. Pinholes limit the area over which lightwaves can reach the retina. $\endgroup$ Aug 3, 2017 at 20:10
  • $\begingroup$ @anongoodnurse Squinting does both; a quick look around the interwebs suggests the pinhole effect predominates, though I didn't look for actual peer reviewed publications. $\endgroup$
    – Bryan Krause
    Aug 3, 2017 at 20:12
  • $\begingroup$ @BryanKrause - You're right! "So basically, squinting allows us to see better in two ways: by changing the shape of our eye and letting in a limited amount of light that is more easily focused." TIL. (And I didn't look on Scholar either. But two science pages stated this. Good enough for me for comments. :)) $\endgroup$ Aug 3, 2017 at 20:16


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