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Comment by User23 | Hacker News Reader

Exactly. For some reason this upsets people.

On the contrary, there's nothing people love more than blaming any problems on what the kids these days are enjoying, regardless of evidence.

The evidence is actually pretty clear, what's causing this vast increase in myopia is not spending enough time in bright environments (i.e. outside) during one's formative years. In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.

If we actually cared about fixing the problem, we'd be making it easier for children to spend time outside and making outdoor environments more welcoming for them. But that would require parents to allow children some freedom, or maybe even actually make some lifestyle changes of their own, whereas the revealed preference of parents is to lock their children up indoors all day and night doing something that looks like "studying" (i.e. pointless drills).

> what's causing this vast increase in myopia is not spending enough time in bright environments (i.e. outside) during one's formative years.

I'd like a source on that. AFAIK the leading factor is so called "near activities", or more specifically, lack of "far activities" (i.e. lack of looking at a distance, which makes your eyeballs get and keep proper shape and characteristics).

> In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.

Again, environment brightness, AFAIK, is way less important than the distance at which you are looking. Hence, looking at the TV is better than at your phone. And I suspect both are better than reading a paper book.

https://pubmed.ncbi.nlm.nih.gov/34142457/

No that's not it at all. It's amazing how people in this thread act like this is a new frontier in health care or something, thinking that genetics and exposure to light are the causes.

It has been determined very conclusively that myopia is caused by spending too much time looking at close objects. That was in my highschool textbook like 20 years ago.

Yes kids should spend more time outside but it has nothing to do with bright environment.

But is it the intensity and spectrum of the light or the fact that being outdoors means your eyes are looking at far more distant objects?

It's purely the brightness. If you're in ambient bright light you don't develop myopia even if you're looking at nearby objects the whole time (e.g. reading books or a phone), if you're in a dim environment you still (are at statistically elevated risk to) develop it even if you're looking at distant objects. This is something they've had to keep doing bigger and bigger studies on because everyone who hears about it has the same kind of thoughts as you did.

OK. A dumb question. So I've been using dim screen brightness to my computer monitor every since I started using glasses. Should I be increasing screen brightness?

Cos I am very serious about having proper lighting on the room I work in. But always thought the screen should be dimmer than the room for some reason.

The short answer is I have no idea. As a matter of personal speculation, I doubt screen brightness makes much difference compared to the huge range that ambient light level can have (about four orders of magnitude IIRC). Most screens look bright at night even on their dimmest setting, and are too dim to read in sunlight even on their brightest setting.

Interesting. Mine has been the least possible brightness with which I can read. Just turned it up a notch to match the room brightness. Let me experiment with it for some days.

Thanks for taking the time to share your POV.

Wouldn't it be brighter settings = less stressom focusing muscles because smaller pupil = higher depth of field.

I can say this anecdotally based on my observations of my elders in my village in India while growing up. They used to avoid getting glasses and eventually their eyesight became worse. I don't think the hypothesis that wearing glasses is causing near sightedness epidemic.

Well, the optometrists I know seem to think this explanation doesn't make sense.

Optometrists are not medical doctors. It's better to consult ophthalmologists (plural) on this. They are better educated and the ones that actually do all the hands-on work on your eyes

I'm an ophthalmologist. Optometrist are very well educated and very competent. They tend to be better at things optics related like refractions, contact lens fitting, etc. and are perfectly capable of managing bread-and-butter medical ophthalmic issues.

Ophthalmologists tend to be better at complex medical management, especially when there are systemic manifestations and own anything requiring surgical intervention.

Optometrists do a 4-year doctorate. Ophthalmologists do a 4-year MD that includes the full spectrum of medical training (gen surg, ob-gyn, neurology, etc.) and then a 1 + 3 residency that includes 1 year of general medicine or surgery and 3 years of medical and surgical ophthalmology.

There are, of course, optometrists who are very good at medical management and ophthalmologists that are very good at refractive issues (e.g. refractive surgeons). We mostly work cooperatively although things occasionally get spicy. I I enjoy working with and learning from my optometrist colleagues. I go to an optometrist friend when I need a refraction and an ophthalmologist friend for my annual.

PS.: ophtalmology residency candidates compete for an absurdly small number of seats in Canada/US, so an ophtalmologist’s opinion on optometrists should be weighed relatively heavily (they’re very smart folks). Commenter is being very humble.

Imagine doing surgery on a pile of wet tissue paper is how I’ve heard retinal surgery described. I’m no expert, but I’d bet it’s even more challenging than most brain surgeries.

I know that. But technically, optometrists have a "professional doctorate" in optometry ("doctor of optometry" or OD), just like doctors have a "professional doctorate" in medicine ("doctor in medicine" or MD). Neither MDs nor ODs are traditional doctors, which is what you would traditionally call someone with a PhD, and not someone who takes care of your health.

I just don't happen to know any ophtalmologists, or anyone with a PhD who specializes in this, and in any case a good optometrist has overlapping expertise and concerns with ophtalmology and current research. Take it for what it's worth, no more, no less.

Why is that? Also what do you mean “seem to?” They do or they don’t, right? Have they not actually told you what they think?

I'm modulating my language simply because I don't have a firm grasp on expert consensus, I only have a handful of optometrist friends, and I usually like to defer to consensus.

I'm not sure why you'd think they wouldn't be honest with me: you should assume good faith.

I am assuming good faith. I wouldn’t ask you why they believe that if I didn’t. Incidentally you didn’t answer my question: “why is that?”

I thought I did answer it with my first paragraph, but if that still seems odd to you we can probably chalk it up to English as a second language or to a misunderstanding.

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