Comment by navjack27
1 year ago
The heck? My earliest memories before I was walking I couldn't see far away. I was born nearsighted and with a lazy eye that caused me to see double. There wasn't anything anyone could do to prevent this. This article is bringing up a whole lot of data but it's not passing the scrutability test. It almost sounds like it wants to blame people for having nearsightedness.
There wasn't anything anyone could do to prevent this.
Maybe they are not talking about you personally. There seems to be strong evidence for time outside being a contributing factor, as one example. That doesn't automatically discount your personal experience, but at the same time any HN reader is well aware the label placed on data from one's personal experience.
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A guy who also has probably been near-sighted since birth
In early elementary-school I would memorize what color clothes my friends were wearing each morning, so that during outdoor recess I could find them without meandering between clusters of kids trying to get close enough to check faces.
Then with glasses: "You mean everybody sees like this!?"
So I was already nearsighted when I still cared about climbing trees and trampolines etc., the books and computers phase came later.
I have been nearsighted nearly my whole life. I started wearing glasses in 2nd grade, probably needed them before then but who knows. I played outside a lot -- we had recess 3x day in school and most days I played outside until dark when I got home. Had very little "screen time" as the only screen in the house was a 12" black and white television.
My suspicion is a lot of it is due to Winter, and shortening recess times, plus increasing reluctance of schools to send kids outside in anything but perfect weather.
Go to school just as the sun’s coming up -> inside recess because it’s too cold or it’s raining a little -> sunset around 5:00PM.
Schools get kids five days a week for most of the winter, so as parents it’s damn hard to get them outside much while the sun’s up on those days if the schools won’t do it consistently. And you need lots of time in very-bright light to cut your odds of myopia to something very low.
Yeah, I think there is a genetic component. I had glasses from the third grade, and I recall spending lots of time outdoors as a youngster. There wasn't much else to do.
> This article is bringing up a whole lot of data but it's not passing the scrutability test.
I disagree. The environmental causes of myopia are very well understood, and have been an area of research for decades and the treatments have been known for nearly as long. Exposure to sunlight at an early age will reduce prevalence of myopia.
They are not saying it's the only cause of myopia. There are people with congenital myopia, such as yourself. But the the bulk of myopia cases are not congenital, they are developed. This is why myopia prevalence increases as a country industrializes, and children spend more time indoors.
Most mammals are born with eyes that don't have a depth (and hence optical focus) set correctly for sharp focus on the retina.
The eyes need to use auto focus mechanisms to tune growth rates to correct for this. If something goes wrong you end up with vision problems.
The brain isn't born able to process visual images and needs training data. If the input from one eye is much inferior during learning image fusion it's input is just discarded and you end up with a lazy eye.
I read that vitamin d deficiency might be related to myopia. It seems controversial though.
Nothing controversial, but it is more likely a correlation, not causation.
If you're vitamin d deficient, that means you're not spending time outdoors (in the sun).
If you're not spending time outdoors, it probably means you're focusing your vision on short-distance objects, like screens and books. Which naturally leads to myopia for most people.
Obviously, vitamin D supplementation is highly unlikely to do anything to improve the condition, because vitamin D deficiency is just a symptom.
Similarly seasonal affective disorder is also very rarely improved by vitamin D supplementation alone.
.. what, how does that track? The article is inscrutable because you happen to have been visually impaired at an early age? What's the logic here?
people weight their anecdotal evidence higher than scientific evidence. shrugs
i.e. "proof by example"
If the article was about people who've lost arms in childhood and you were born missing an arm, would you still assume it were about you?
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