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Comment by progfix | Hacker News Reader

I am not sure if this is related, but I am heavily short sighted and facing the sun with closed eyes for a couple of minutes sharpens my eyes.

I suspect it is just because I tend to spend too much time in dark rooms and in front of screens and being in the bright sun "fixes" that for a while.

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Your pupils become narrower and probably stay that way for a while when you open your eyes. This gives you a sharper image.

Look up "pinhole camera" for a good explanation of this effect. These cameras don't even need a lens!

Yes, I asked an optician and he said the same thing. He said pinhole effect. It goes away after a few minutes.

It's forcing your pupils to constrict. Decreasing the aperture size on a lens increases the field of view. So, while your eye might not be able to accommodate at the correct distance given the current convergence point, there is more room for error. It's a fairly common method in photography, in cases where one might have difficulty getting a correct focus on a subject. It's not a "fix", but a compensation.

Depth of field is what expands with smaller apertures, not field of view. The former is the range of distances that are "in focus", and the latter is the angular width of the the scene.

> Decreasing the aperture size on a lens increases the field of view.

No, the aperture has no effect on the field of view. They are orthogonal features of how a lens works.

I think the commentator meant "depth of field"

yes, didn't have my first coffee yet

There's a theory that one cause of myopia is lack of high intensity light due to indoor living:

https://pubmed.ncbi.nlm.nih.gov/29371008/

dr andre huberman on JRE a couple days ago talked about this as well as OP's article.

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