Comment by AstixAndBelix | Hacker News Reader

Comment by AstixAndBelix | Hacker News Reader

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LCD screens are a wonderful technology that has unfortunately been adopted for a whole range of unsuitable applications.

this article talks about writing, but I want to highlight the viewing part.

LCDs were not made to be stared at for hours on end, e-ink displays on the other hand were made exactly for that purpose. they don't tire your eyes more than a piece of paper and they require external light to be visible. this is very much in tune with how every single object has worked in the whole history of humankind until the invention of artificial illumination.

in my opinion working for 8 hours in an office starting at an LCD screen should be considered as damaging as sitting at a computer for 8 hours with an incorrect posture. you end up with a headacke and your eyes burn, and the rest of the day is just painful to continue.

this wouldn't be the case if some technology was invented that had the refresh rate and color palette of standard LCD screens while having the pleasant viewing experience of digital paper. I think many people would drop their books or even their e-book readers if normal tablet or computer monitors weren't painful to look at.

If your LCD is tiring your eyes, it's set too bright. E-ink has the advantage that it automatically shows the correct brightness for the lighting conditions, but there's nothing inherently less tiring about it. I have keybinds set to change my monitor brightness using DDC, so I can easily adjust my LCD's brightness as needed.

> If your LCD is tiring your eyes, it's set too bright.

The race for brightness considered harmful :)

The problem that LCDs have and CRTs didn't is that you lose color reproduction/contrast if you turn down the brightness to healthy levels.

Hopefull OLED fixes that and becomes affordable. But I'm afraid manufacturers will still race for brightness even on a technology that doesn't need it.

> E-ink has the advantage that it automatically shows the correct brightness for the lighting conditions

Tbh I find eink very readable in bright sunlight and it's all downhill from there, to the point that i prefer reading on a tablet with brightness way down and the lights off to eink with a lamp on. But that may be a consequence of staring into LCDs most of my life.

There's even software that can adapt that DDC brightness automatically using the ambient light around you. I develop Lunar (https://lunar.fyi) that can do that for macOS.

For me, the screens I use are always at the brightness where white regions are as comfortable as a piece of paper. Sure, colors aren't reproduced "as the artist/developer wanted" at those values, but neither do I need that, nor do we have e-ink screens that can reproduce color more accurately.

I just want to create software, research stuff on the internet, arrange my music etc. and if I feel like doing that for 10 hours straight, I only want the screen to tire my eyes as little as possible.

I also read a lot of books and research material, both on Kindle and paper. My eyes get tired after hours of doing that as well. Light is not the only factor.

So although it's good to try to be optimal about the light that gets in your eyes over large periods of time, it's best to also try periodic rest and moving some activities to non-screen mediums instead of fretting endlessly over the last 5% of screen light optimization.

I've been looking for this software for ten years. My eyes thank you!

> E-ink has the advantage that it automatically shows the correct brightness

It doesn't because e-ink is a non-light-emitting technology so has no concept of brightness. Ambient light is what lights it up usually (unless one turns an entirely optional backlight on to read in the dark). So you don't need to adjusts as there's nothing to adjust, it's literally ambient light bouncing back, so is the same brightness by virtue of being the same light source.

Conversely, typical displays (TN, IPS, OLED, CRT even...) being a light emitting technology, one needs to turn backlight up as ambient light increases as both compete. (That is, unless it's a transflective LCD, but even then it's quite dim in ambient light).

> there's nothing inherently less tiring about it

e-ink really is more like paper, while typical displays are like turning a flashlight straight towards your eyes.

but the e-ink displays have a dull gray background. While printer paper is the bright bleached white which a lot more pleasing and easier to read.

>there's nothing inherently less tiring about it

e-ink doesn't flicker.

I know that past a certain number of Hz our brain just mushes the images together and we magically perceive that the motions on the screen are fluid, just like we believe our electric lights are completely on all of the time. But even though our final perception might be continuous, maybe there are steps in the image processing pipeline in our brain where something gets overloaded by the discrete refreshing of the screen.

My LCD doesn't flicker either. Some LCDs use pulse-width modulated backlights, which do flicker, and there are gaming LCDs with optional strobing to improve motion clarity, but these are not inherent to the LCD technology.

> not inherent to the LCD technology.

actually they kinda are

Blue light from close distance screens is the enemy of your eyes and has many other side effects.

https://health.ucdavis.edu/blog/cultivating-health/blue-ligh...

The amount of blue light emitted by an LCD depends on the backlight used. Some brands advertise low blue light. You could even build an LCD with zero blue light emission if you wanted to, at the cost of being unable to display blue. And even with a conventional backlight, you can reduce the blue light to very low levels in software, e.g.:

https://en.wikipedia.org/wiki/Redshift_(software)

E-ink reflects light over a broad spectrum, so the amount of blue depends on the amount of blue it's illuminated with. It can be higher than the LCD in some conditions.

not disagreeing, but you can't chose the display of the laptop most of the times.

Besides, in the last 2 years people reported many more cases of eye strain and blurred vision (at least in my country), because "home" is not really the best work environment for 95% of the people.

There's a reason why offices are always well illuminated.

e-inks are usually used with lights turned off and when ate not I use the red light because it's better for reading.

Maybe you're misunderstanding the usage of "flicker" here. I'm not saying that I can see my monitor flickering, because nobody can past a certain refresh rate. What I'm saying is that any monitor inherently flickers because of its refresh rate, independently of our perception.

Refresh rate is not the same as flicker.

Refresh rate is the rate at which new information is displayed. Flicker is things turning on and off.

As the parent mentioned, some screens use fast cycles of turning on/off to modulate perceived brightness, but this is not always the case.

I'm not entirely sure if what's being said is true but I believe the intention is to stay:

All LCDs "flicker" in the same way all movies "flicker". The technology simply displays or flashes a series of still images quick enough to be perceived as fluid motion or video.

I'm not sure that's the intention, because they said that "e-ink doesn't flicker". But e-ink certainly has a refresh rate. So I think they attribute some other form of flickering to LCD.

(And in fact, some of the e-ink readers with optional display lighting will use PWM to modulate its brightness, and then exhibit flicker. This is a super dumb engineering choice, though, so it's not very common. The Kobo Forma was an offender.)

Fair point. E-ink does refresh the entire screen though, correct? It's closer to a old-school slide projector than a monitor. I admittedly know little about this topic.

As an aside, I'd love a secondary e-ink monitor. Hopefully the technology improves so prices come down.

> E-ink does refresh the entire screen though, correct?

No, e-ink displays and controllers support partial updates.

Thank you for the correction.

>But e-ink certainly has a refresh rate

of course it has a refresh rate when there is a change in the image, but if I'm reading something completely static then literally nothing changes whereas an LCD screen still does things in the background

On an LCD also nothing changes when the display image is static.

When the image is not static, because an LCD updates line by line, if you don't coordinate your data updates to the refresh rate you can get artifacts such as "tearing", where different sections of the monitor show different data that doesn't fit together. However, e-ink displays doing differential or fast partial updates have similar problems (and some exciting new ones, making refresh overall quite bad). You just usually don't try to display fast moving imagery on them.

e-ink displays are what is known as "bi-stable", meaning you don't need to apply a voltage to keep a pixel in a particular state, only when you want to change that state. This is not true for LCD, where you do need to keep supplying a voltage. This however doesn't result in any visual change if the voltage isn't changing.

The real difference here is that LCDs aren't reflective, unlike e-ink. So you need a backlight, and that light shining at your eyes is more tiring than how things work with an e-ink display. That either doesn't need a backlight (in a bright ambiance), or the LED lighting isn't behind the display and doesn't shine directly at you, but rather bounces through the display surface. This is a nice quality.

If you lower the brightness on an LCD screen, it's going to have terrible contrast even if you use the lowest possible black because the "black" on that kind of screen is achieved by filtering out polarized light. Additionally on some screen models, low brightness is obtained by flickering the backlight which only adds to the discomfort.

When lowering the hardware brightness (either through the monitor OSD or through DDC), the voltage of the LED backlight gets lowered and thus the LEDs get dimmer and less light passes through the crystals. Polarization doesn't come into effect here.

What you're describing happens when lowering the brightness through software (either Gamma adjustments or a dark overlay) because in that case you're only changing the software pixels to be darker.

Although even in that case, newer miniLED/quantumDot LCD screens also lower the LED brightness when pixels get darker, because they have more granular control and dimming an LED doesn't cause shadows over a large area of the screen anymore.

Changing the brightness of an LCD screen does not affect the contrast of the emitted light. The lowest possible black is some percentage of the backlight brightness, not a fixed value. You can see this by changing the brightness while displaying a pure black image. LCDs do also reflect some ambient light, so turning down the brightness will reduce the contrast slightly in most environments, but many LCDs have anti-reflective coatings to mitigate this.

LCD typically has higher maximum contrast than e-ink.

[citation needed]

You make many unsubstantiated claims. I don't get headaches from staring at an LCD even 14h/day.

> I don't get headaches from staring at an LCD even 14h/day.

You are probably a young person (sorry for assuming)

I didn't get headaches when I was 18 and stared for 14 hours straight at a 1024x768 14 inches CRT monitor at 85Hz interlaced.

p.s.: the term you're looking for is "screen headaches"

p.p.s.: http://oaxis.com/lcd-screens-harmful-effects/

I’m 51 and have been staring at screens for 40 years, on average rather close to the amount of time I’m awake, and I can’t really connect that to headaches.

I’m in my 40s and don’t get these. How old do you have to be before they set in?

I have glasses— without those, I’d probably get a headache. I also use a very high quality 5k monitor and proper lighting. Maybe those make a difference? Maybe I won the genetic lottery? Dunno.

I don't get headaches, but know many people who do and the frequency have increased lately during covid.

What I suffer from since Covid restrictions settled in and had to work from home all the time, confined in a space that cannot be easy illuminated properly, is blurred vision.

I don't suffer from it after reading an ebook on an e-ink in natural light, but I do after a day of work in front of my laptop display (can't easily move the 30 inches display I had at work because insurance, laws, bureaucracy etc) so mine it's not exactly a scientific study, but a close friend of mine she's an optometrist and she said to me that people reporting eye strain, blurred vision and headaches have almost doubled.It affects older people much more than the younger ones of course, but are treating kids too, that were a rarity before.

They all have in common spending a lot of time in front of an LCD displays at home.

I'm middle 40s.

Same, never got any headaches from any screens. Regardless of the type of the screen, lighting or viewing position. Have been using computers for almost 25 years, with many 10h days and occasionally 15+ hours.

As I got older I started getting neck pain though, if I sit too awkward. But still no headaches ;)

I am 30. I guess that is young-ish. I try to take care of my health.

Even basic colour support (like 3 colours in addition to black, no grayscale) with a 1Hz refresh rate might be enough for me...

And I would have expected us to have them by now, considering how colour e-paper has passed the prototype stage and is now widely used in supermarkets for labels ??

Working for 8 hours in an office is already considered damaging, staring at LCD or a pile of paper.

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