Where are all the blind people?

[JSWolf]

Originally Posted by leebase

We've had tv's for 60 years or so. Computer screens for 40.

But they don't count until they became LCD for the purposes of this thread.

[pazos]

Originally Posted by MGlitch

We can also say that the moon being made of cheese has a negative affect on our eye health. Except it doesn’t because it isn’t. People have read at night for generations, since before we had electricity. It’s not overly difficult. And it’s become less and less difficult over the years prior to frontlight ereaders.

I don't see any point there. People can read at night. Without environmental light it was impossible until thirty of fourty years ago.

Does people get blind because the reading? Nope, I didn't said so. I said that reading without any environmental light is a bad habit, that can degrade the hability of your cone cells to react to light changes.

As reading is a quite difficult task for the brain (I mean recognize and processe glyphs vs other patterns, like faces, or composing movement based on retina persistance) it needs quite a few micro-movements more (called sacchaic movements in english, or at least by google translate ).

Having a good light environment (not too bright, not too dim) is recommended for these kind of tasks. In general the recommendation is more light comming from the environment that from the source of the read. That's why I talked that both lcd and e-ink tech are allowing bad habits, because it is now possible to read in the dark. And, nope, is not possible to read without using the cones, so we're screwed .

[cfrizz]

Originally Posted by 4691mls

I sit upright in front of a computer monitor most of the day at work. That's ok because I'm up and down doing other things. But I can't imagine being comfortable enough sitting in front of my computer at home to want to do any extended reading there. Do you have a really nice chair or something?

Of course I have a nice comfortable chair, and I do get up since I usually have a drink next to me and have to get up to let it out.

I've been using terminals/pc's since 1981 when I started working at the age of 20. I have always had bad eyesight and went through a 10 year period of changing eyesight from about 30-40 which the eye doctor said was NORMAL (and welcomed me to MIDDLE AGE!) for everyone. I go every single year to have my eyesight checked, and my eyesight has been stable now closing in on 20 years since I've been reading with the same pair of glasses at least that long.

If screens were having a damaging effect on my eyes it would have been detected decades ago.

So as Lee and DD have stated, the claims of screens being bad for eye health are just wishful thinking and out right lies.

[JSWolf]

Originally Posted by pazos

In fact we could say that e-ink/lcd are both worse than a paper book because they allow bad practices, like reading in the night, which are too difficult to replicate with a real book.

That's a load of rubbish. I used to read at night with pBooks. When I was a kid, I'd do the flashlight under the covers in order to read.

[pazos]

I'm not interested too much into the discussion. Read at night without environmental light is a bad habit. Smoke is a bad habit too even if your granfather was a smoker and lived a whole century. Yeah, I know, what a poor comparation-

If you want to ditch a bit on human perception I would recommend the book https://www.springer.com/gp/book/9783319317892.

For more (scientific) knowledge about how the eye work you could read https://iovs.arvojournals.org/articl...icleid=2164197

[DNSB]

Originally Posted by pazos

I don't see any point there. People can read at night. Without environmental light it was impossible until thirty of fourty years ago.

I have memories of being told how my several greats grandmother used to spend her evenings reading and writing pamphlets for women's suffrage in the 1870's on. Candles and kerosene lamps were the lighting of choice in those days.

[MGlitch]

Originally Posted by pazos

I don't see any point there. People can read at night. Without environmental light it was impossible until thirty of fourty years ago.
.

I’m assuming there is some major language barrier here.

You initially claimed eink let us develop bad habits like reading at night. Which is a blatantly wrong claim, people have read at night for longer than anyone reading this has been alive. Nothing about eink makes this exceptionally easier just more convenient since frontlight ereaders produce less unneeded light and have sleep timers to shut off if we fall asleep while reading.

Now you’re claiming without environmental light it was impossible until 30-40 years ago. Which is again a claim which is easy to disprove. People read at night over 100 years ago.

I don’t know where you’re getting this information, but if you paid for it, you should demand your money back.

[pazos]

Originally Posted by MGlitch

I’m assuming there is some major language barrier here.

Yeah, surely! Actually my english is very bad, sorry for that!.

I'm talking about ambiental light, natural or artificial. The case mentioned by DNSB would fall in ambiental light too.

It is called ambiental because it is not looked directly (you don't look at the source of the light (sun or candle) directly but used the reflected light to see other stuff.

When I was talking about reading without environmental light I meant: read in the dark with no other source of light and that wasn't possible until computers, AFAICT.

My first claim was some sort of a joke. I didn't state that lcd / eink tech itself is bad but enable us to acquire bad habits.

My second claim still holds.

[Frenzie]

Originally Posted by pazos

When I was talking about reading without environmental light I meant: read in the dark with no other source of light and that wasn't possible until computers, AFAICT.

I don't know, is it really that different than reading by a candle or a reading light? Their ambient light seems negligible.

Of course I'm assuming a low brightness there; if you set it to 100 % then there's a rather obvious difference with a candle.

[pazos]

Originally Posted by Frenzie

I don't know, is it really that different than reading by a candle or a reading light? Their ambient light seems negligible.

Of course I'm assuming a low brightness there; if you set it to 100 % then there's a rather obvious difference with a candle.

The main difference is that the fovea is looking at the screen while reading, not at the candle. The rest of the eyes, composed mainly by rodes, have almost no role in visual acuity, but there are a few cones there too that serve for acommodation purposes.

In short: light distribution over the retina matters.

I'm talking about the behaviour of the eye, not really about our perception of it. If the brain/experience has some role then we're talking about constructivism and that's another topic.

Links:

Wikipedia article about the fovea
visual axis of the fovea

ergonomics: lux levels for outdoor/indoor

[jj2me]

Originally Posted by pazos

The main difference is that the fovea is looking at the screen while reading, not at the candle. The rest of the eyes, composed mainly by rodes, have almost no role in visual acuity, but there are a few cones there too that serve for acommodation purposes.

In short: light distribution over the retina matters.

I'm talking about the behaviour of the eye, not really about our perception of it. If the brain/experience has some role then we're talking about constructivism and that's another topic.

Links:

Wikipedia article about the fovea
visual axis of the fovea

ergonomics: lux levels for outdoor/indoor

I was about to give my worthless anecdote before I came upon your posts (I had no idea of this science).

So I'm guessing if we want to read at night, it's better for our eyes to:
a. read in a lighted room,
b. prefer using a non-frontlit e-reader over a frontlit reader or LCD. If the ambient light where you are seated is not enough, then attaching an auxiliary booklight to the non-frontlit e-reader is slightly preferable to a frontlit e-reader with its more uniform light (the auxiliary booklight generally won't reflect evenly across the e-reader, so the distribution of light over your retina is more varied.

In your judgement are those the correct best practices for e-reading at night?

[AnotherCat]

Originally Posted by jj2me

I was about to give my worthless anecdote before I came upon your posts (I had no idea of this science).

So I'm guessing if we want to read at night, it's better for our eyes to:
a. read in a lighted room,
b. prefer using a non-frontlit e-reader over a frontlit reader or LCD. If the ambient light where you are seated is not enough, then attaching an auxiliary booklight to the non-frontlit e-reader is slightly preferable to a frontlit e-reader with its more uniform light (the auxiliary booklight generally won't reflect evenly across the e-reader, so the distribution of light over your retina is more varied.

In your judgement are those the correct best practices for e-reading at night?

You are letting yourself get confused by amateur fabricated "science", or grasping at something that suits your agenda.

The comparisons regarding the fovea only apply to looking directly a strong concentrated source of light, such as looking directly at the candle itself very close up or into a larger strong light such as a lamp. What has been described would apply, for a device example, if looking into a phone or tablet's camera's/torch high intensity flash LED.

Nothing to do with low level light emitting or reflective displays because they have comparatively large plane surfaces relatively evenly and lowly lit and in the cases of E Ink and LCD also diffused.

But like drowning men there are some who will hear nothing that is contrary to their claims of danger and will continue to try to convince people by quackery and fabricated "science" in order to support their argument. Nothing will change their minds but hopefully threads lead by a claim such the OP has stated will encourage those of more rational thought to question scaremongering claims as to the safety of displays.

[murraypaul]

Originally Posted by MGlitch

If you’re setting the bar that low, we’ve seen an increase in the number of people who need glasses.

Being pedantic, but we've seen an increase in the number of people getting and wearing glasses. That isn't the same as an increase in the number of people who need them, in an objective way, such as measuring vision on an eye chart.
Perhaps it is just that there are fewer people who should get glasses, but don't?

Sure there could be any number of causes there, but the uptick in using screens more follows that same trend.

Could also be cause and effect is reversed here.
People want to play on their clever new gadgets, but realise their eyesight isn't good enough, so get glasses.

[Frenzie]

Originally Posted by murraypaul

Could also be cause and effect is reversed here.
People want to play on their clever new gadgets, but realise their eyesight isn't good enough, so get glasses.

That doesn't seem like a very plausible explanation for the worldwide increase among school-attending children, which has always been based on those silly eye charts.

[murraypaul]

Originally Posted by Frenzie

That doesn't seem like a very plausible explanation for the worldwide increase among school-attending children, which has always been based on those silly eye charts.

No, but it might be a contributing factor for older people.

https://www.theweek.co.uk/93139/myop...n-need-glasses

This hypothesis holds true even for populations with little exposure to screens - studies in Israel show that orthodox Jewish boys who spend long days poring over printed religious scripture suffer from a far higher rate of short-sightedness than their secular counterparts.

Spending all of your time focusing on something at a fixed, close distance at a young age may be bad for your eyes, whether it is a screen or not.