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Why do CRTs cause eye strain?
- Thread starter Jospeh
- Start date
Why do LCDs cause eyestrain?
Both are valid questions, are mostly specific to each individual and can be argued about for a long, long time.
Basically, though, a good CRT should not cause eyestrain. If the refreshrate is high enough (75-85 Hz), the resolution comfortable and one isn't hunched behind it for hours on end, there should be no factors that would cause eyestrain.
LCDs, however, especially cheaper TN panels suffer from backlight flicker, polarized light (not everyone deals with it equally well), colour/gamma shift, non-equal brightness of the backlight across the screen, a trade-off between either retina-scorching brightness or awful saturation, and a very 'sharp' picture (CRTs have a smaller dot pitch and the phosphors will 'smooth' the picture a bit), which can all cause eyestrain.
Having used many CRTs and LCDs over the years, I can honestly say that CRTs are my preferred type of display when it comes to eyestrain, or the lack thereof.
Both are valid questions, are mostly specific to each individual and can be argued about for a long, long time.
Basically, though, a good CRT should not cause eyestrain. If the refreshrate is high enough (75-85 Hz), the resolution comfortable and one isn't hunched behind it for hours on end, there should be no factors that would cause eyestrain.
LCDs, however, especially cheaper TN panels suffer from backlight flicker, polarized light (not everyone deals with it equally well), colour/gamma shift, non-equal brightness of the backlight across the screen, a trade-off between either retina-scorching brightness or awful saturation, and a very 'sharp' picture (CRTs have a smaller dot pitch and the phosphors will 'smooth' the picture a bit), which can all cause eyestrain.
Having used many CRTs and LCDs over the years, I can honestly say that CRTs are my preferred type of display when it comes to eyestrain, or the lack thereof.
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Ive never had a problem with eye strain on CRT's with at least 75 and higher refresh rates. I used to run a NEC 20WMGX2 LCD as a secondary monitor and it would strain my eyes after extended use, It might of been due to the brightness of the screen but it occurred even when I lowered it (shrug). Im currently running a solo CRT and have my Plasma hooked as secondary for movies.
FoxhoundOp
[H]ard|Gawd
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I've never experienced eyestrain on any LCD. I haven't really had it on CRTs either except for crappy ones running at 60 Hz.
There's more at play here than just CRT vs LCD.
I found that I suffered eyestrain, whether CRT or LCD, if the room was not lighted properly. Using a monitor or TV in a dark room is the short path to eyestrain, at least for me. The room light doesn't need to be particularly bright, just enough. Indirect lighting from behind and to the side is ideal.
The color of the bezel may also matter. Supposedly, a light grey/silver bezel is best to reduce eyestrain, while a black bezel is the worst.
Having the sharpness set correctly on an LCD is key to making text look better and, probably, to reduce eyestrain. Use the lagom.nl Sharpness test to find the correct sharpness setting for your monitor. Each monitor has a different correct setting, and often it is not the default setting. Also, when using Windows, make sure Cleartype is set correctly.
I have been using a 20WMGX2 heavily - up to 12 hours a day - with no eyestrain whatsoever. I have the brightness set to 32% and it feels just right.
I found that I suffered eyestrain, whether CRT or LCD, if the room was not lighted properly. Using a monitor or TV in a dark room is the short path to eyestrain, at least for me. The room light doesn't need to be particularly bright, just enough. Indirect lighting from behind and to the side is ideal.
The color of the bezel may also matter. Supposedly, a light grey/silver bezel is best to reduce eyestrain, while a black bezel is the worst.
Having the sharpness set correctly on an LCD is key to making text look better and, probably, to reduce eyestrain. Use the lagom.nl Sharpness test to find the correct sharpness setting for your monitor. Each monitor has a different correct setting, and often it is not the default setting. Also, when using Windows, make sure Cleartype is set correctly.
I have been using a 20WMGX2 heavily - up to 12 hours a day - with no eyestrain whatsoever. I have the brightness set to 32% and it feels just right.
CRT 1
CRT 2
So LCD technology is preferable if you care about your health.
There are some more obvious reasons.
LCD technology provides better text rendering (higher contrast, less blurry, more readable), no irritating problems with geometry and focusing, larger working space - no need to deal with tiny objects on the screen, advanced egronomics, eye strain reducing technologies (auto brightness, dynamic brightness), screens with no reflection (unless you want it).
Cyberbeing
Gawd
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The only time I have gotten eye-strain was from my old CRT (which soon after failed completely), when I had a LCD sitting right beside it.
My eyes are very photosensitive. With one right beside the other, and the CRT set to 120Hz, I could still see flicker on the CRT. Moving my eyes back and forth between the two monitors seeing that flicker difference, along with the difference in text readability and brightness (which LCDs excel at), caused me eye strain. I wouldn't be surprised that if I would have calibrated the luminance on the LCD to match the CRT, the problem would have gone away, but at that point I hadn't invested in a calibration puck, so I'll never know.
My LCD started having issues and was eventually returned to Dell for a refund as they were unsuccessful in providing a working replacement. Soon after that, my old CRT failed. Once I bought a brand-new CRT and had it as my only monitor, by eyes eventually adjusted. I can still see the flicker even at very high refresh rates, but I no longer get eye strain. Me being able to see flicker seems to be more of an issue on larger CRT monitors. For a short time before I bought a new monitor, I was using a small crappy non-flat 15" CRT, and I didn't have much of an issue with seeing flicker.
As evilsofa mentioned, using any monitor in a dark room, without the luminance turned way down (say <85cd/m2), will cause eye strain during long term usage for most people if sitting very close. Having a bit of background light goes a long way in reducing that effect.
My eyes are very photosensitive. With one right beside the other, and the CRT set to 120Hz, I could still see flicker on the CRT. Moving my eyes back and forth between the two monitors seeing that flicker difference, along with the difference in text readability and brightness (which LCDs excel at), caused me eye strain. I wouldn't be surprised that if I would have calibrated the luminance on the LCD to match the CRT, the problem would have gone away, but at that point I hadn't invested in a calibration puck, so I'll never know.
My LCD started having issues and was eventually returned to Dell for a refund as they were unsuccessful in providing a working replacement. Soon after that, my old CRT failed. Once I bought a brand-new CRT and had it as my only monitor, by eyes eventually adjusted. I can still see the flicker even at very high refresh rates, but I no longer get eye strain. Me being able to see flicker seems to be more of an issue on larger CRT monitors. For a short time before I bought a new monitor, I was using a small crappy non-flat 15" CRT, and I didn't have much of an issue with seeing flicker.
As evilsofa mentioned, using any monitor in a dark room, without the luminance turned way down (say <85cd/m2), will cause eye strain during long term usage for most people if sitting very close. Having a bit of background light goes a long way in reducing that effect.
Gorankar
[H]F Junkie
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With CRT's running at an appropriate, for screen size, resolution at 75 to 85Hz or better, in a properly lit room, typically ends the issues.
However, CRT's can get fuzzy looking at higher resolutions with refresh rates over 100-120Hz. Not usually noticeable in games, but if I try reading for a bit it will give me a headache.
However, CRT's can get fuzzy looking at higher resolutions with refresh rates over 100-120Hz. Not usually noticeable in games, but if I try reading for a bit it will give me a headache.
Because most people were unable to set proper refresh rates, many were even sitting in front of monitors with 60Hz, not able to see that flickering!
With my 19" CRT I used 1152x864@100Hz, which caused no headaches for me.
And of course, bad lightning conditions.
But I think also LCD marketing had played a role in persuading people, that CRTs are actually a health damaging piece of junk.
With my 19" CRT I used 1152x864@100Hz, which caused no headaches for me.
And of course, bad lightning conditions.
But I think also LCD marketing had played a role in persuading people, that CRTs are actually a health damaging piece of junk.
novemberrain
Weaksauce
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I don't know, but I suppose it's the flicker, visible on not. But I've never had any problems, even when playing at 60hz. On the other hand I've seen many lcds flickering so bad (PWM brightness control I suppose) that they are really pain to watch. Also many lcds are so bright even on the lowest setting that you must leave lights on or your eyes will get burnt.
btw. I've sit thousands of hours in front of a dual CRT screen setup and never had any problems. Actually when I think of it, they're very comfortable on the eyes.
btw. I've sit thousands of hours in front of a dual CRT screen setup and never had any problems. Actually when I think of it, they're very comfortable on the eyes.