Just read a summary of the state of play on myopia (short-sightedness). It’s always been a chicken and egg thing. Do shortsighted people get that way because they do lots of close work, or do they do lots of close work because that is what their eyes like. Turns out it might not be anything to do with close work at all. Might be more to do with light levels/exposure to sunlight.

Lots of background in this Nature piece, for those interested.

http://www.nature.com/news/the-myopia-boom-1.17120

There is obviously a pretty good genetic link, but some nurture effects as well.

too much indirect sunlight would weaken the eyes, I would think

it would effect people who work outside a lot

people in flat treeless areas may be exposed to more levels of sunlight as the horizon is much brighter than the rest of the sky

I dont like brightness, I have my monitor down at 50 percent and it still looks bright to me

http://en.wikipedia.org/wiki/Myopia

Education and IQA number of studies have shown the incidence of myopia increases with level of education, and many studies have shown a correlation between myopia and a higher intelligence quotient (IQ).

A 2008 literature review reported studies in several nations have found a relationship between myopia and higher IQ and between myopia and school achievement. A common explanation for myopia is near-work. Regarding the relationship to IQ, several explanations have been proposed. One is that the myopic child is better adapted at reading, and reads and studies more, which increases intelligence. The reverse explanation is that the intelligent and studious child reads more, which causes myopia.

According to the two most recent studies, higher IQ may be associated with myopia in schoolchildren, independent of books read per week. Myopia is more common among students in gifted education.

This is to be contrasted with hyperopia, the incidence of which is associated with lower IQ and educational attainment.

Other risk factorsIn one study, heredity was an important factor associated with juvenile myopia, with smaller contributions from more near work, higher school achievement and less time in sports activity.

Long hours of exposure to daylight appears to be a protective factor. Researchers at the University of Cambridge have found that a lack of outdoor play could be linked to myopia.

Other personal characteristics, such as value systems, school achievements, time spent in reading for pleasure, language abilities and time spent in sport activities correlated to the occurrence of myopia in studies.

Another explanation is that pleiotropic gene(s) affect the size of the brain and the shape of the eye simultaneously.

transition said:

http://en.wikipedia.org/wiki/Myopia

Education and IQA number of studies have shown the incidence of myopia increases with level of education, and many studies have shown a correlation between myopia and a higher intelligence quotient (IQ).

A 2008 literature review reported studies in several nations have found a relationship between myopia and higher IQ and between myopia and school achievement. A common explanation for myopia is near-work. Regarding the relationship to IQ, several explanations have been proposed. One is that the myopic child is better adapted at reading, and reads and studies more, which increases intelligence. The reverse explanation is that the intelligent and studious child reads more, which causes myopia.

According to the two most recent studies, higher IQ may be associated with myopia in schoolchildren, independent of books read per week. Myopia is more common among students in gifted education.

This is to be contrasted with hyperopia, the incidence of which is associated with lower IQ and educational attainment.

Other risk factorsIn one study, heredity was an important factor associated with juvenile myopia, with smaller contributions from more near work, higher school achievement and less time in sports activity.

Long hours of exposure to daylight appears to be a protective factor. Researchers at the University of Cambridge have found that a lack of outdoor play could be linked to myopia.

Other personal characteristics, such as value systems, school achievements, time spent in reading for pleasure, language abilities and time spent in sport activities correlated to the occurrence of myopia in studies.

Another explanation is that pleiotropic gene(s) affect the size of the brain and the shape of the eye simultaneously.

ok I was way off

Have there been any studies in using different fonts in relation to myopia?

>>Have there been any studies in using different fonts in relation to myopia?<<

Fairly unlikely to be relevent. Did you read the link? It gives the developmental outline.

I quite like the light levels idea.

interesting read.

http://www.nature.com/news/the-myopia-boom-1.17120

“Retinal dopamine is normally produced on a diurnal cycle — ramping up during the day — and it tells the eye to switch from rod-based, nighttime vision to cone-based, daytime vision. Researchers now suspect that under dim (typically indoor) lighting, the cycle is disrupted, with consequences for eye growth. “If our system does not get a strong enough diurnal rhythm, things go out of control,” says Ashby, who is now at the University of Canberra. “The system starts to get a bit noisy and noisy means that it just grows in its own irregular fashion.”

“Rose points out that additional outdoor time “has to be mandated through the schools, because getting parents to voluntarily do this is extremely difficult”. Saw and her colleagues learned this when they trialled a 9-month programme to teach parents in Singapore about the importance of outdoor time in order to prevent myopia. They provided step-counters, organized outdoor weekend activities for families and even offered cash prizes for cooperation. But by the end of the trial, the time spent outdoors was not statistically different from that for a control group with no such campaign13.

In some places, children cannot get any more outdoor light: there are too few hours of daylight, the sun is too fierce, or the cold too intense. Animal research10 has suggested that powerful indoor lights could do the trick instead: light boxes currently sold to treat seasonal affective disorder, for example, can deliver up to 10,000 lux illumination, but their effects on myopia have not been tested extensively in humans.”

Might be a combination of lack of broad daylight and lack of need to focus on faraway objects.

According to that article the incidence of myopia in four Asian countries (Hong Kong, Singapore, South Korea, and Taiwan) increased 400% in 40-60 years. That’s staggering.

Thanks buffy. Interesting article.

thought this was interesting “has to be mandated through the schools, because getting parents to voluntarily do this is extremely difficult”, that children might get something (more) of childhood back (the outdoor experience), and that school at the same time would provide sunshine.

‘m longer boats

btm said:

According to that article the incidence of myopia in four Asian countries (Hong Kong, Singapore, South Korea, and Taiwan) increased 400% in 40-60 years. That’s staggering.

Thanks buffy. Interesting article.

It is quite amazing. Started to be noticed some 15 to 20 years ago when the grandparents were fine and the grandchildren were becoming myopic. Mad searching going on for ways to slow it down, ‘cure’ it, prevent it. Without anyone really knowing what was causing it. Atropine has been used, with only minimal effect, although it might help if it is a light level thing as it dilates the pupils and would increase the amount of light hitting the retina.

It’s been difficult reading myopia research in the last 20 odd years because you have to be careful to see where it was done and on what population because what has been happening in Asia has not been happening here. So all sorts of discussions about race characteristics and stuff.

It would be so simple if it’s just a matter of making sure kids spend some time outside in the sunshine. There will still be myopes because of the genetic bit. (I should state my position…..I come from a line of myopes, it’s most certainly genetic in my paternal line)

I’ve been personally suspicious of quite a lot of the things offered by way of amelioration.

buffy said:

btm said:

According to that article the incidence of myopia in four Asian countries (Hong Kong, Singapore, South Korea, and Taiwan) increased 400% in 40-60 years. That’s staggering.

Thanks buffy. Interesting article.

It is quite amazing. Started to be noticed some 15 to 20 years ago when the grandparents were fine and the grandchildren were becoming myopic. Mad searching going on for ways to slow it down, ‘cure’ it, prevent it. Without anyone really knowing what was causing it. Atropine has been used, with only minimal effect, although it might help if it is a light level thing as it dilates the pupils and would increase the amount of light hitting the retina.

It’s been difficult reading myopia research in the last 20 odd years because you have to be careful to see where it was done and on what population because what has been happening in Asia has not been happening here. So all sorts of discussions about race characteristics and stuff.

It would be so simple if it’s just a matter of making sure kids spend some time outside in the sunshine. There will still be myopes because of the genetic bit. (I should state my position…..I come from a line of myopes, it’s most certainly genetic in my paternal line)

I’ve been personally suspicious of quite a lot of the things offered by way of amelioration.

Maybe it has just become cool to wear glasses?

No, they are definitely myopic. It’s easy to measure and generally can’t be fudged.

:)

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

buffy said:

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

a case of short sightedness is probably better than ocular melanoma. Not that I know what the rates of cancer sunnies v no sunnies is.

Ocular melanoma is very, very rare. And probably like the ones like liver and other internal organs. Because they tend to be on the optic nerve (not exposed to sunlight) or in the peripheral retina (exposed to much lower levels). Sometimes external on the conjunctiva though.

http://www.sciencedirect.com/science/article/pii/0039625788901737

Quick summary of epidemiology of uveal melanoma. It’s rare.

I saw someone recently (in the last three years) with it – eye removed. Patient still alive. But has to be constantly monitored….they are a bit nasty in being a bit metastatic and I think his was right on the nerve. Had another lady many years ago who also had her eye removed. Some 20 years on she is still going and looking like old age will get her rather than her melanocyte’s’ wild children.

buffy said:

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

At my sprogs primary school they mandated that they were all to have, and wear, sunglasses during the summer whilst outside. It only lasted one year, and I must admit I have no idea why its implementation was dropped.

sibeen said:

buffy said:

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

At my sprogs primary school they mandated that they were all to have, and wear, sunglasses during the summer whilst outside. It only lasted one year, and I must admit I have no idea why its implementation was dropped.

Well durr, all the kids became too kool for skool.

sibeen said:

buffy said:

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

At my sprogs primary school they mandated that they were all to have, and wear, sunglasses during the summer whilst outside. It only lasted one year, and I must admit I have no idea why its implementation was dropped.

—

http://www.davidicke.com/forum/showthread.php?t=122562

sibeen said:

buffy said:

I did wonder about the wearing of sunglasses in the young. When I graduated we had the attitude that we had evolved in sunlight and kids didn’t need to wear sunglasses. I wouldn’t be surprised to find that coming the full circle.

At my sprogs primary school they mandated that they were all to have, and wear, sunglasses during the summer whilst outside. It only lasted one year, and I must admit I have no idea why its implementation was dropped.

If all the kids are, well, kids, their parents got fed up with lost, damaged sunglasses that were only worn for two days.

It’s hard enough to get my kids to wear their hats and not lose them. Sunglasses were a complete nightmare. It’s only now that they’re getting close to their teens that they’ll even attempt to look after something like sunglasses.

Well I’ve never worn sunglasses and have spent most of my life outside in bright sunlight. The other parts of my life have been involved in doing lots of close work. So close in fact that magnification is a necessity. Yes my eyes have deteriorated to the point where I now need magnification of 1.5 to read street signs. However I have been a smoker for longer than many people live. I can no longer count the hairs on a roo’s nose at 100 m and I need magnification greater than 4 to read the phone book. I was diagnosed with the affliction of high IQ at a tender age and have read lots of books by torch or candlelight and spent a lot of time inches away from flouro lights with 12x loupe in one eye.

Nobody has ever described me as being myopic. Perhaps it was the luck of my genetics.

buffy said:

Just read a summary of the state of play on myopia (short-sightedness). It’s always been a chicken and egg thing. Do shortsighted people get that way because they do lots of close work, or do they do lots of close work because that is what their eyes like. Turns out it might not be anything to do with close work at all. Might be more to do with light levels/exposure to sunlight.

Lots of background in this Nature piece, for those interested.

http://www.nature.com/news/the-myopia-boom-1.17120

There is obviously a pretty good genetic link, but some nurture effects as well.

Is there any mention that myopia can sometimes improve without warning? Mine improved by 1 dioptre in one eye and 0.75 dioptre in the other eye over a period of less than three weeks during a mid-life crisis. I have the optometrists reports to prove it filed somewhere. It turned out that I had been unable to relax before then and was keeping part of my bodily tension in my eye muscles.

I concluded that it’s exceptionally important for optometrists to get patients to completely relax their eye muscles before testing for myopia.

It’s even more important to get hyperopes (long sighted) people to relax. A myope will usually not be holding their accommodative muscles in spasm. Your description sounds like you might be an accommodater and were never actually a myope. You are right that we need to be careful when refracting. An accommodator will just accept more and more minus power lenses as they accommodate over them. It can be difficult, but there are ways of refracting. Interestingly, if you are refracted with an autorefractor – a machine that shines light in and works out your prescription by optics equations – you are more likely to be given a myopic reading. This is “instrument myopia”. A tendency to focus close when you look into a machine/instrument because your brain says what you are looking at must be close because it is inside the instrument.

All these things are supposed to be in the mind of the optometrist when refracting. It’s a bit of an art.

Isn’t there evidence that submariners tend to become myopic? They never look at the horizon for months on end.

buffy said:

It’s even more important to get hyperopes (long sighted) people to relax. A myope will usually not be holding their accommodative muscles in spasm. Your description sounds like you might be an accommodater and were never actually a myope. You are right that we need to be careful when refracting. An accommodator will just accept more and more minus power lenses as they accommodate over them. It can be difficult, but there are ways of refracting. Interestingly, if you are refracted with an autorefractor – a machine that shines light in and works out your prescription by optics equations – you are more likely to be given a myopic reading. This is “instrument myopia”. A tendency to focus close when you look into a machine/instrument because your brain says what you are looking at must be close because it is inside the instrument.

All these things are supposed to be in the mind of the optometrist when refracting. It’s a bit of an art.

I like that. Thanks for the explanation. “An accommodator will just accept more and more minus power lenses as they accommodate over them.” I’ve had periods in my life like that. By the way, that sudden 0.75 and 1 dioptre improvement in myopia was slowly lost over the next 10 to 20 years.

mollwollfumble said:

buffy said:

Just read a summary of the state of play on myopia (short-sightedness). It’s always been a chicken and egg thing. Do shortsighted people get that way because they do lots of close work, or do they do lots of close work because that is what their eyes like. Turns out it might not be anything to do with close work at all. Might be more to do with light levels/exposure to sunlight.

Lots of background in this Nature piece, for those interested.

http://www.nature.com/news/the-myopia-boom-1.17120

There is obviously a pretty good genetic link, but some nurture effects as well.

Is there any mention that myopia can sometimes improve without warning? Mine improved by 1 dioptre in one eye and 0.75 dioptre in the other eye over a period of less than three weeks during a mid-life crisis. I have the optometrists reports to prove it filed somewhere. It turned out that I had been unable to relax before then and was keeping part of my bodily tension in my eye muscles.

I concluded that it’s exceptionally important for optometrists to get patients to completely relax their eye muscles before testing for myopia.

Probably assisted by staring blankly into the distance.

And thinking further on this today, I realized we’ve known about form deprivation myopia for a very long time. It was a subject of research with animals when I was a student nearly 35 years ago. This link give far more information than you could ever want, but it is all there:

http://ilarjournal.oxfordjournals.org/content/40/2/59.full#content-block

It’s well written and has further refs if you want to go further. It’s about animal models of myopia, but it covers the basic human stuff as well.