NYT: Do E-Readers Cause Eye Strain?

[Verencat]

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[Demas]

So for people actually interested in the discussion rather than creating conspiracy theories not settled with the tacit statement of "none"....

Even if you reject the premise of the article- that reading habits are more controlling with respect to eyestrain than display technology- and further accept the premise that some other technology is required... the question is what features does that technology have to have in order to go mainstream?

Rather than box your desires by existing technological categories what is the feature set necessary?

Presumably the bottom line is readability [given bad habits]. Rich media, responsiveness, color, etc. are what the mainstream want on top of that, but for a reader-centric crowd, readability is first (however you get there, even if it includes better responsiveness for a better page-turning experience, etc). So better than paper in the dark, lower than reflective in bright light, and always persisting at a comfortable level of nits respective to the environment (within reason).

Looking at the feature set it seems that whatever the future is it HAS to be emissive because no reflective technology can cover that gamut of lighting conditions... so the question then turns to, "If it glows it blows... WHY?"

The eye is merely an organ that takes in light and transmits the signal via electro-chemical impulses... so what is the qualitative empirical difference between reflected light and emissive light that should cause a [non-psychosomatic] response in the reader?

Presuming an emissive display were to project a perfect hologram of a piece of paper... would that be acceptable?

[DawnFalcon]

"what is the qualitative empirical difference between reflected light and emissive light that should cause a [non-psychosomatic] response in the reader?"

This question is still unanswered, of course. There is clearly by the studies a difference which goes beyond ambient lighting, but the exact cause - and why some people are more affected than others - remains an open question. I keep up with the literature on this, and there is no proposed mechanism which survives serious scrutiny as far as I know. (And if there's a paper I've missed, please feel free to link it to me)

However, to say that screens "must" be emissive because only it can cover a wide range of light conditions is utterly missing the point. Not only are many emissive screens utterly unreadable in direct light (and hence cannot "adapt" beyond a certain level), there are also minimum brightness levels which even LED lighting can make. You have to look at how often people actually tend to read in different light levels - reflective epaper screens are suitable for a wide range of them, including in direct sunlight.

What you can't really do is dismiss the effect given it's wide reporting by a subset of people, even if you yourself don't suffer from it. People's personal choice of reading device is up to them, and why "if it glows, it blows" is a histrionic turn of phrase, the eyestrain some people suffer does make reflective, non-backlit devices their only real choice for on-screen reading.

More than that, you can use a dedicated frontlight to light a reflective screen, but a non-reflective screen has few options when outside it's designed ambient range of illumination. While epaper is not ideal for everyone, there is no evidence that it will become extinct in the near or even mid-term.

In the long term, certainly, as displays advance then it's likely dedicated epaper screens will fade out, but it'd be premature to say which specific technologies will do.

(And it's not a "conspiracy theory" to wait - and to dismiss early hype about a product - until there are actual end-hardware samples and reviews from a company with zero track record before accepting any statements on their product's marketworthyness!)

[m-reader]

Originally Posted by kjk

http://bits.blogs.nytimes.com/2010/0...er=rss&emc=rss

Proper scientific study. Not!
This is nothing but difference in opinion argument. Everybody is right, of course. I would like to see some proper scientific data on this subject.

[AprilHare]

Okay. I didn't read the article, but:
- Human eyes get strained if you stare intently too long at anything. E-paper, paper, LCD, CRT, rock - anything.
- Human eyes get strain from staring at a intense light source, such as LCD, a light globe, etc.
- Human eyes get less strained when looking at reflected light. So E-paper and paper have the advantage here (as long as the reflected light is at a reasonable level - staring at the Moon not so much).
- Human eyes can get strained by flashing lights. Bad refresh rate LCD, CRT, lights flickering at the supermarket, whatever. E-paper and paper have the advantage here.
- Human eyes get strained when looking at excess detail. Looking at far distances without optical assistance can do this, and I suppose 1080i displays for the wrinkles on a baby would do this.

I really don't know what the agenda here is and frankly I don't care. I'm satisfied my Sony Reader isn't wrecking my eyes any more than paper reading does.
If you're concerned about sore eyes with your epaper, stop blaming the epaper.
Use common sense people!

[Demas]

You didn't provide a balanced view however...
- Human eyes get strained by poor contrast, where LCD has the advantage.
- Human eyes get strained by dim lighting conditions, where LCD has the advantage.
- Human eyes get less strained when looking at poor text rendering which can occur with low DPI, small manufacturing lots, only 16 levels of grey, and proprietary software coming from consumer e-ink devices as opposed to LCD APIs for mainstream OSes (this very issue occurred with the Kindle 2, though eventually patched).
- Human eyes won't get strained by anything with a high refresh rate, including LCD... equivocated ones with poor refresh rate is like equivocating low-quality e-paper solutions like TFT with e-ink.
- Human eyes get strained with too little detail in attempting to resolve text, but neither too much nor too little detail is trouble for a versatile LCD which can use non-native resolutions.

[AprilHare]

Demas, I thoroughly disagree.
Dim lighting conditions are when there isn't enough light to allow the eye to easily resolve detail. That's not a problem with paper/epaper as long as you use a light source LCD is a poor light source as it is typically too bright, and human eyes don't cope well with reading (or indeed viewing) a bright light source intently or for long periods.
The contrast on epaper is perfectly adequate and is at no practical disadvantage.
I hold that the text rendering on epaper is typically excellent and not an issue with respect to DPI. Can you tell the characters apart? Of course you can, easily. Therefore, no 'poor text rendering'. Hell, you can even increase font size with a push of a button! Try doing that with paper! Greyscale count, small manufacturing lots and 'proprietery software' are utterly irrelevant.
E-paper does not have low refresh rate. It has no refresh rate. It only refreshes when changing the display from one page to another. Which is good, as poor refresh rates can make viewing hard. Most modern displays do not suffer from poor refresh rate.
Human eyes *love* low detail. If we're talking about 6 pixels to describe a symbol then yeah there's a problem. But this is hardly the case.

Originally Posted by Demas

You didn't provide a balanced view however...
- Human eyes get strained by poor contrast, where LCD has the advantage.
- Human eyes get strained by dim lighting conditions, where LCD has the advantage.
- Human eyes get less strained when looking at poor text rendering which can occur with low DPI, small manufacturing lots, only 16 levels of grey, and proprietary software coming from consumer e-ink devices as opposed to LCD APIs for mainstream OSes (this very issue occurred with the Kindle 2, though eventually patched).
- Human eyes won't get strained by anything with a high refresh rate, including LCD... equivocated ones with poor refresh rate is like equivocating low-quality e-paper solutions like TFT with e-ink.
- Human eyes get strained with too little detail in attempting to resolve text, but neither too much nor too little detail is trouble for a versatile LCD which can use non-native resolutions.

[DawnFalcon]

Originally Posted by Demas

- Human eyes won't get strained by anything with a high refresh rate, including LCD... equivocated ones with poor refresh rate is like equivocating low-quality e-paper solutions like TFT with e-ink.

A common view, but based on a false premise, that Human eyes work like an electronic device. However, in actuality even high "refresh rates" can cause eyestrain. This is because the eye does not update in a linear fashion, unlike electronic devices.

More, one identified issue is not how bright the device is, but the difference in lighting levels between the device and the ambient light. Matching for a TFT device is often badly done, and backlighting (and on non-reflective devices, you cannot simply turn it off...) has a minimum illumination level. This is less of an issue with LED-lit screens than CCFL-lit ones, but the issue does still remain.

You persistently refer to ereader screens as "low quality", when in fact e-ink displays are typically higher ppi than most laptop screens (handy table, most 6" epaper readers being 166 ppi).

You are showing a clear bias here: Greyscale does not per-se cause higher levels of strain, assuming a reasonable handling of the fonts in the rendering engine (and ADE does, although Apple's does not), small batch production has nothing whatsoever to do with eyestrain (regardless, E-Ink screens are now in mass production, and SiPix screens will be from day one, hence this objection is invalid), and so on.

I don't mind you holding a bias, but it does need to be clear that you are holding one against current epaper devices: while they do have very real issues...

[Demas]

My point is that you're being disingenuous by leaving out the issues with e-ink expressly highlighted by the article, but to address the points

- Dim lighting is contentious because now that you're introducing a light source it isn't dim lighting anymore. Reflected light to overcome the dim lighting is no different that backlighting to overcome the dim lighting unless you stack the deck.
- The contrast is lower than quality newsprint which is an issue for me, but if you want to add subjective modifiers like "perfectly adequate" and "practical" then LCD gains that benefit with the refresh rate.
- Text rendering was EXPRESSLY an issue with Kindle users, just check their support forums. The DPI is lower than magazine print, again an issue, and small lots mean the level of QC either results in higher costs or lower quality displays (compared to mass produced LCD which can afford a higher discard rate).
- I'm well aware of how e-ink works, my point is that raising a negative that "most modern displays do not suffer" is disingenuous; as if I were to raise TFT as an equivalent reflective technology (the example I gave above).
- I disagree about the detail, please read this study: http://billhillsblog.blogspot.com/20...f-reading.html

[Demas]

As an addendum, I'm not entirely sure you understand what is meant by text rendering since you said levels of grey is irrelevant, when that's arguably one of the most relevant aspects to antialiasing text (unless you have sub-pixel rendering which e-ink does not). The issue isn't the ability to interpret text, but to resolve the edge detail of individual characters. With poor text rendering, your eye can't help but attempt to autofocus something that will never resolve, resulting in fatigue.

(Kindle text rendering problem; source: Wired)

[DawnFalcon]

Actually, there's a massive difference between lighting just the screen and lighting the surroundings. The second will cause lower eye strain: this has been studied.

Text rendering was an issue on the K2, yes. Amazon's custom rendering solution had issues which have not affected the used-by-many-readers ADE: it's incorrect to draw any conclusions beyond a software bug on a single model of reader. And while the DPI is "lower than magazine", it remains higher than all but a few specialist TFT panels.

And that's not a study, it's an opinion on Slate and a journalism school's website.
This is a study, about the lighting issue I mentioned.

[Demas]

Originally Posted by AprilHare

Okay. I didn't read the article, but:
- Human eyes get strained if you stare intently too long at anything. E-paper, paper, LCD, CRT, rock - anything.

Use common sense people!

In fairness, you did say this, which coincides with the article and debunks any attempts to take non-comparative eyestrain out of context. It is irrelevant that eyestrain exists on any one object, what's relevant is comparative empirical differences which you started a list of... and hopefully I've completed.

We can do rocks and paper if you want too.

[AprilHare]

I wonder what the Notion Ink Adam will be like to view?

[m-reader]

Seriously boys and girls.
This is a "How long is a piece of string" argument.
Does anyone know of any proper scientific study on this issue?
For me personally (and for my wife), EPD wins hands down. This however is hardly a scientific argument ...

[LCF]

Originally Posted by DawnFalcon

Except of course eyes don't have a linear refresh rate. So that comparison is nonsense*.

*Actually, I'd use far FAR stronger terms.

Very well said!
Also worth mentioning - by staring into the LCD you forget to blink. So this strains the eyes most of all, because of the thin liquid layer infront of your eye which just evaporates. So much about science.

My personal opinion and study:
I read 8h on the CRT monitor - I feel like crap.
I read 8h on the LCF monitor - I feel like a smaller crap.
I read 8h on my LBook - I feel tired, but nothing compared to reading on screen.
I read 8h on paper - Somewhere around the LBook, somethimes better, somethimes worse, depends on paper color, light, if I'm studying or just reading for fun ( ).

To summarize: Every time I think about the moment, when I had to decide if I give 330 € for an eBook reader or for a Netbook, I congratulate myself for making the right decision.