Comment by ChuckMcM
4 years ago
kind of, kind of not. To the extent that brightness contracts your pupil, and the depth of field available to your eye increases with smaller pupil size[1]. People with focus issues find they can always focus when the light is bright enough (assuming normally functioning pupils).
So there are optical properties that are affected by bright light, and your eyes respond to that. What the mechanism is for affecting overall focus range of your eye? I would agree that is unstated/unknown.
[1] Which, as a science project, is fun to demonstrate that a pin hole camera doesn't need a lens for this reason.
Please do research on myopia progression. It's not unknown. This entire thread is full of people guessing at things they don't have any experience in.
A brief look at citations on Wikipedia seems to contradict everything you've said. Maybe you'd like to link some research?
Your reply is a good example. I haven't seen anyone in this HN post's comments talk about how myopia works. I legitimately do not understand why so few people know even the basics of myopia progression. All of these comments are, pun intended, the blind leading the blind. I especially don't understand it given how common myopia is and how important it is for parents to understand it for their children.
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1. Glasses that blur what's on peripheral vision https://abc11.com/amp/4176773/
> too much time spent in front of a screen confuses the eye, since everything is in focus. The eye keeps growing, leading to myopia.
2. Glasses to stop myopia are successful in multi-site trial https://newsroom.uw.edu/news/glasses-stop-myopia-are-success...
Glasses with fogged edges prevent over focus:
> What’s supposed to happen as your eye grows, is that things should begin to go out of focus in the periphery of your vision. That’s a signal for the eyes to stop growing.
3. Multifocal contact lenses slow myopia progression in children https://www.nih.gov/news-events/nih-research-matters/multifo...
> Animal studies have shown that focusing light in front of the retina cues the eye to slow growth.
4. Putting contact lenses on monkeys _causes_ myopia and removing them slows myopia growth https://www.nature.com/articles/s41598-019-48009-3
5. "How Atropine Eye Drops Can Slow Myopia Progression" https://www.myopiainstitute.com/eye-care/how-atropine-eye-dr...
> Applying atropine eye drops dilates the pupils and temporarily paralyzes the focusing muscle inside the eye. It also relaxes the eyes’ focusing mechanisms.
Your eye grows without your brain's involvement. Sharp focus on the back of the eye, especially in the periphery, tells the eye to grow longer because it's overfocusing. This leads to the worsening of myopia. Things that cause sharp focus on the retina and fovea: contacts, glasses, and holding things close to your face that keep everything in focus. This may be why being outside is correlated with slowing myopia progression, because you wont have things constantly in focus in your peripheral vision from it being close to you.
I have a serious question: did you not come across any of this research? No one seems to have familiarity with these concepts in this HN thread. Did you see articles like these and skip over them? Or, maybe, were you only googling for myopia and sunlight, which is unlikely to return results like these?
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