Will Flat Screens Save Your Eyes? 49
An unnamed corrrespondent asks: "Are LCD flatscreen monitors better for your eyes than CRT's? Have studies shown that LCD's reduce eyestrain, red-eye, or other eye fatigue compared to CRT monitors due to less radiation, no flicker, or other differences in the technology?" Studies aside, I certainly find it more comfortable when working for hours at a time to be staring at a nice TFT LCD than even a high-quality CRT, which is one reason that I'm growing resigned to laptop keyboards.
Re:But what about games / movies and such ? (Score:1)
I have next to no experience with modern LCD's, but I do know that they have not used crystals that can move fast enough to keep up with video/games/animation. Though, the quality now days is, likely, not bad, I would guess that if you sat a good CRT next to an LCD and played a game on both, the CRT would win in the bluriness factor.
Something I like to do is go into a Radio Shack, Best Buy, or your local computer shop and test drive a system with an LCD on it. The shop will probably have some sort of demo movie running on the machine that will give a pretty good idea of what the screen will look like during a game.
All that aside, I would still love to get a good LCD at work (I don't game there). Staring at a CRT for 8+ hours daily gets to you after a while.
Re:May save your eyes but... (Score:2)
Re:lcd's are a so-so compromise (Score:1)
Therefore even with my monitor set at 75Hz I get annoyed by the flickering when I'm looking away from the monitor but with it still in my peripheral vision.
Re:May save your eyes but... (Score:1)
Re:my tft... (Score:1)
Re:Bring back monochrome. (Score:2)
There's one other significant difference between monochrome and color monitors.
If you look at two monitors that were produced, say, 10 years ago, you'll notice some significant differences. The color VGA monitor, even at the default 640x480 resolution, still has somewhat fuzzy text. In contrast (pun intended), the monochrome monitor has very sharp text.
This is because of the dot pitch used on those older monitors, and the whole issue of having a screen mask (dots commonly, or wires with a Trinitron display). Because monochrome monitors didn't have a mask, there's nothing that diffuses the electron beam striking the phosphor. There are also no focus and alignment issues with multiple electron guns.
Back at school, we had 19" monochrome monitors for our Xterminals, they rocked! Too bad you can't buy that kind of stuff anymore.
Of course, now I'm completely dependent on my LCD screens (SGI 1600SWs of course). I am so spoiled, I don't know how I managed without colorization of program code and color-ls.
Re:lcd's are a so-so compromise (Score:1)
Re:May save your eyes but... (Score:2)
Re:May save your eyes but... (Score:3)
It would be nice if PC vendors adopted the ADC. I'm not sure if there are any patent or licensing issues. When I got my Apple LCD display, I took it out of the box, put it on the desk and attached a single cable to the Mac. Turned on the Mac and everything worked perfectly.
May save your eyes but... (Score:1)
If I have to use one, it must be set at 800x600 just to half-read the text on the screen. My laptop has better quality fonts at 800x600.
Flicker threshold (Score:1)
I believe the flicker threshold for most people is somewhere between 60 & 75 Hz (though I don't have any references to back this.) For the same reason, the frame rate in games like Quake III don't give additional perceptual improvement beyond 75 fps. As long as you set your monitor's refresh rate to 85 Hz or higher, monitor flicker shouldn't be a problem.
Re:Cheapskates! (Score:1)
The aspect ratio is all wrong. It's like watching a movie.
When I'm doing admin work, I don't want to watch a movie. That's what the 36" TV in the den is for. %-)
CRT's definitely better! (Score:2)
I myself chose the 21" CRT over the 18". Not only is a) the resolution higher; b) the screen bigger; but c) it looks _sharper_.
Sun's 21" tube is a Sony Trinitron OEM'd. And it's probably the BEST 21" tube I've ever used.
We're split about half-and-half between the CRT's and LCD's. Truthfully, the LCD is a bit brigher (albeit fuzzier), but working a long day on the CRT tube is painless. It's a GREAT tube.
I've worked only for a few hours on the LCD's at a time, not a full, long day, but I truly missed my CRT.
Possibly (Score:1)
my tft... (Score:1)
last semester worked on an AI project for 61 hours, with only minor sleep. my eyes were fine, whereas my buddy had a brutal headache. his 19in crt had done him in.
even tho i've had my IBM T86 for 6 months now, i'm still impressed how good it looks.
if you can afford one, don't hesitate, go an get one. it'll be worth the money. paid $4000 (canadian) for mine with not a single regret.
peace.
Re:my tft... (Score:1)
Re:my tft... (Score:1)
don't live with the folks either, don't think i could handle that, hahahah.
Re:What about radiation? (Score:1)
Re:CRT's definitely better! (Score:1)
TFT are the way to go (Score:1)
Now I have never looked back at desktop PCs again ! My latest work machine is another Dell laptop with a 15" 1400x1050 TFT. The picture is so beautifull and sharp
Re:lcd's are a so-so compromise (Score:1)
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Genius dies of the same blow that destroys liberty.
Re:May save your eyes but... (Score:1)
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Genius dies of the same blow that destroys liberty.
But which LCD? (Score:1)
But on the 15" LCD, you pay about $300 more for XtraView than for the simpler display. That difference alone would pretty much pay for a 17" CRT with a similar viewing area.
Re:Bring back monochrome. (Score:3)
And my eyes were never as bad when I was 15 years younger either. What's your point?
Black on white displays...just another thing that we have Mr. Jobs to thank for. Yet another Apple innovation that looks looks cool and really doesn't serve much purpose [especially now that screens don't burn in so easily].
_____________
Re:Bring back monochrome. (Score:1)
The really optimal colors are black text on a wheat background. It's not as bright at white, and still has a very good contrast to it.
I'll also bet your eyes were younger when you were on monochrome displays :)
Re:Possibly (Score:2)
Looks like behind (just try to focus on a piece of dust on your screen and compare to where the image is: looks like some 3mm behind).
Solution: keep your screen dust free, so your eyes won't find any point of reference on the glass surface, and the only thing it notices is the image. If the image is at the "wrong" place, make sure the eye does't know where the right place should be...
Static flicker isn't the only issue (Score:1)
Motion of the eye introduces the problem of stroboscopic effects. A refresh rate which is more than fast enough to be undetectable to a single detector cell your eye is quite a different matter if your eye is panning fast enough. Instead of seeing shapes and edges moving across the field of vision, bright areas in dark fields leave a string of bright dots on the retina while dark areas in bright fields do something similar to (but not exactly) the opposite. Motion-detector cells, which are evolved to deal with more or less constant illumination, don't work properly under such conditions. The motion cues and other little details which your eyes ought to have to aid their tracking across the page are subtly wrong. What this leads to I don't know, but I am aware of some research which showed that people's eyes take longer to scan to particular words on a printed page under flickering fluorescent light than under incandescent light (no word on what effect high-frequency electronic ballasts might have had).
So far as stroboscopic effects are concerned, there is little difference between 60 Hz and 85 Hz. You could eliminate this with long-persistence phospors, but nobody wants to watch their screen smear into an indecipherable blur every time something scrolls. Face it, the CRT is far from an optimal display interface to the human eye.
--
Knowledge is power
Power corrupts
Study hard
Re:my tft... (Score:1)
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Ancedote (Score:1)
I don't know the science or the stats, but I know my eyes: TFT LCD bests any CRT I've used.
That said, unless I could get 1024x768 resolution I would even dream of using a LCD (I need the space!).
Re:Ancedote (Score:1)
Perhaps they do, but you failed the reading comprehension test: my point was not the relative merits of the CrystalScan, but how short-term exposure to the Toshiba LCD changed my appreciation of what had been satisifactory previously.
Re:my tft... (Score:1)
University education is ALOT cheaper here in Canada, the Government pays 80-90% of tuition fees. Some people live with their parents too, so they don't have to pay rent/food/bills/etc, leaving them with money to spend on toys.
As for the LCD vs. CRT thing, I have a laptop with a 15" 1400x1050 display, it's crisp like you wouldn't beleive. The viewing angle thing is the only negative that I have with them. Though, it's advantages more than makes up for its for it's disadvantages (lighter, smaller, no alignment/rotation/focus problems, no flicker-headaches, etc.).
Re:Flicker threshold (Score:1)
Re:lcd's are a so-so compromise (Score:2)
Yes, there is a speed beyond which the human eye cannot track changes in briliance (ie ammount of light) fast enough. Basically nervous conections have a minimum recovery time between passing two nervous impulses - if i'm not mistaken, for neurons it's about 18 ms (i got this from my neural networks class some years ago).
So, even if the optic nerves were faster than this, the information couldn't get to the brain any faster.
EMP Scream (Score:3)
The basic principle of CRTs is to produce light by firing high speed electrons against a "brick wall" (actually lead and glass if i'm not mistaken). The problem is that, when a high speed electron is quickly decelerated (as in hitting a solid surface), it will release energy across the whole Electro-Magnetic spectrum (what i call an EMP Scream).
Guess what - i'm siting just behind one of those brick walls, getting bombarded by thousands of bilions of electrons per minute. The tought is not very conforting ...
Re:lcd's are a so-so compromise (Score:2)
I've always been a little curious about this; I know the brain can subconsciously (and sometimes consciously) see the image refreshing if the refresh rate is too low, but does it really get that much better if the refresh rate is set really high? Does the eye ever get physiologically incapable of seeing it refresh?
Personally I like my flatscreen at work, simply because I have to look at it for 12 hour stretches at a time, and it's a lot easier on the eyes. A good crt has much better image quality I think though.
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TFT versus CRT (Score:1)
From: http://www.feds.com/nll_lib/ctd/ctd0706.htm [feds.com]
cyberFEDS - CTDNews - Vol. 7, Issue 6 - June 1998
>>Comments interspersed are mine.
Ergo jury on flat panel displays still out
The emergence and initial success of flat panel displays have raised question about their ergonomic design and health impact, particularly in comparison to the conventional computer monitor.
Most, if not all monitors, bundled with computer systems today are cathode-ray tubes, which project a beam of electrons onto a screen to produce an image.
Flat panel displays (FPDs), which remain secondary purchases for computer users, produce an image when an electrical current passes through a liquid or gas contained between two plates. Variations include liquid crystal, gas plasma and electroluminescent FPDs.
The benefit of FPDs, according to manufacturers and some ergonomists and researchers, is the visual improvement over cathode-ray tubes and maximized desktop space.
On the matter of size, FPDs are designed to be more "flat." They are not as deep as conventional VDTs and, therefore, allow computer users more workstation space. For example, a 20-inch cathode-ray tube could be about 20-inches deep, while a comparable FPD could be only a couple of inches thick.
Like a mirror, FPD could be mounted on a wall or the back of a cubicle.
That flexibility and the reduced area to accommodate monitors pleases many ergonomists, particularly as computer workers are being asked to work around CPUs, keyboards, mice, printers, modems, telephones, external hard drives, etc.
>>Amen. I just bought my first laptop last year, and I can't say enough good things about the TFT monitor. The display certainly seems easier on my eyes. The flexibility component may have more to do with the fact that it's a laptop, though.
However, the health impact is not as convincing. James Greeson, president of Ergonomic Solutions Inc. and editor of the International Standards Organization's FPD standard, said, "It's a kiss-your-sister kind of story. There's no conclusive scientific evidence that flat panel displays are visually more dangerous or superior to cathode-ray tubes." (The flat panel display standard is ISO 13406.)
He also noted the FPD image is pixelated, meaning images -- letters, numbers, symbols, graphics, etc. -- are made up of tiny dots, which can be seen in some cases.
"This is not an ergonomic defect. It's not dangerous. But it is an image quality detractor," said Greeson.
>>This effect is noticeable on my screen, but not terribly distracting, IMO.
Leading manufacturers like DTI (an IBM-Toshiba partnership), Fujitsu, NEC and others argue FPDs are vastly superior to the tubes. In their promotional literature and posted on their websites are claims of how FPDs dramatically reduce eye strain.
Recent studies have highlighted increased glare and reflection problems associated with FPDs, but the studies also reveal general user preference of FPDs over CRTs.
>>The glare issue is easily resolved. Tilt the screen away from the light. I had lots of trouble with glare in office buildings. The clunky CRTs were difficult to move. Beyond that, there are only so many positions possible with something that heavy and ponderous. Fluorescent light is also tremendously hard on my eyes, which is why I avoid office buildings these days.
No less important in the debate over whether to upgrade to flat panel displays is the price. They command a hefty price tag in comparison to a CRT. Market researchers estimate an FPD to be about five times the cost of a comparable CRT, though it may be only three times the price by the end of this year.
>>All of my praise aside, were I to buy another desktop computer, I would not now shell out the extra dough for a flat panel display.
FPDs are gaining popularity in the desktop publishing, medical financial and military fields, the research indicates.
>>Perhaps that statement indicates a preference for FPDs by those who work with graphically-based applications. Perhaps the sharp text is more desirable to those who code. (My work leans more toward desktop publishing, so maybe this explains my preference for the TFT monitor.)
Bring back monochrome. (Score:2)
At home I use text-mode applications exclusivly, with all text in a single primary colour. I'm on the lookout for a cheap dumb terminal (preferably green on black) for the spare room.
My eyes were never as bad when we used monochrome monitors and text only apps.
Re:Flicker threshold (Score:1)
IIRC, 72 Hz is considered the lowest flicker-free frequency. Personally, I can catch my console flickering only in my peripheral and only when the screen is solidly colored (like with ntsysv), and that's 68 Hz. X is fine at 75 Hz, and horrendous at 60 Hz.
Cheapskates! (Score:1)
Actually, I've been lusting over one myself, but I can't begin to justify the $2200.
Hey, I just noticed the 24" crt is LESS than the 18" lcd. So why not opt for the bigger crt?
24" Sun Monitor [sun.com]
Re:May save your eyes but... (Score:1)
-mdek.net [mdek.net]
LCD vs CRT (Score:1)
I spend all day looking at a LCD, even if it is only a passive matrix, and i find much easier on the eyes than a CRT, the exception being when stuff moves around, and a good active matrix pretty much eliminates this problem.
As far as EMF and power consumption goes, LCDs come out far better.
If price was no object, then i'd much rather have a high quality LCD (have you actually looked at a Cinema Display with your own eyes, rather than reading reviews) but for my home PC, there's no way i'd fork out the $$$, and instead will get a flat screen trinitron.
-- kai
Verbing Weirds Language.
Less glare (Score:1)
lcd's are a so-so compromise (Score:3)
but what really matters most to me is the fidelity/luminence of a given display's ability to show red. this is where tfts fall short.
But what about games / movies and such ? (Score:1)
Re: (Score:1)
Re:May save your eyes but... (Score:1)
Re:May save your eyes but... (Score:3)
If you use Windows and don't want to download Microsoft Reader, I suggest trying out Steve Gibson's ClearType Sub-Pixel Font Rendering Demo, available here [grc.com], which is a small application to demonstrate ClearType technology.
Also, Slashdot (last year) ran an article on ClearType technology here [slashdot.org].
Are LCDs better for you? (Score:4)
Quoted directly:
21. Are LCDs better for you?
There is some research work that has been carried out that suggests that LCDs should be easier on the eye than CRT monitors, because the eye finds it easier to focus on the sharply-defined pixel edge. One or two small research projects have found evidence to support faster reading speeds on LCDs. Anecdotal evidence also points to users being happier to spend longer periods looking at LCDs. There are also reports from users that they can find it difficult to constantly switch between the two technologies.
In the future, LCDs are likely to run at higher resolutions than CRTs, with consequent improvements in reading speed and accuracy.
-snellac
What about radiation? (Score:1)
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loosing all hope is an ideal