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Will Flat Screens Save Your Eyes?
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.
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.
user@host:/usr/bin$ whatis
java: nothing appropriate.
I think you might want to checkout the reccomended resolution for the monitor. If the fonts look screwy, then it's just that the video card is running the monitor at a different resolution than the monitor runs natively. Switch the videocard's resolution to match the monitor's resolution.
Peripheral vision is more sensitive to flickering than regular vision.
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.
SGI 1600SW - 17" extra-wide display for ~ $1500 direct from SGI, ~$1400 from dell.com (out of stock). Make sure you get the multi-link adaptor. You'll also need a video card that supports DVI (and LCDs, some cards have DVI but can't run some LCDs).
The T86's are down to ~ $1k USD. See ubid.com and pricegrabber.com.
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.
Dead pixels are not all that frequent, at least for me. My Dell 1024x768 display has one bad pixel, and I notice it only rarely.
You might want to look at the Apple LCD display. It uses a digital interface (Apple Display Connector) between the video card and display, avoiding the problems inherent in LCD displays that are driven by analog video.
Mea navis aericumbens anguillis abundat
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.
Mea navis aericumbens anguillis abundat
I don't know about you folks, but all of the desktop flatscreen LCDs that I've seen have terrible font quality! Everything is all blurry!
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.
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.
Meldroc, Waster of Electrons
They _would_, if I wanted it.
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. %-)
As someone who works for a rather large telco firm, we get our hands on decent displays. All of the admins in my group have one of two monitors: Either Sun's 21" premium flat CRT or Sun's 18" LCD.
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.
One thing I've heard is that CRTs give the appearance of an image where it really isn't (either in front or behind), therefore making it impossible for the eyes focus in the image. With LCDs, this doesn't occur and they should theoretically be easier to look at. I know I prefer my 12" laptop LCD over a 15" Trinitron any day.
...is super easy on the eyes.
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.
Newer CRT's don't radiate more than the wires we've all got running through our walls. and that too is significantly less than the 60W light bulb you've got hanging over your head, emmitting a faint glow.
Geek rants since like... 2000 or something.
I used to be a fan of big heavy PCs with huge CRT screens. Then I was forced on day to go for a laptop, so I bought what was a nice and expensive Dell laptop with 14" TFT screen.
:) Although the resolution seemed to be a little too high for the screen size, it's still much more readable than anything else and provides plenty of screen real-estate. Now going back to work on a CRT, even a good one, is a real pain. Also I like the ability to have one and only one PC at work and at home (no more syncing of files and emails to do)
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
You tend to see the flicker when you move your eyes, which can hurt quite a bit if you're reading for a long time.
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Genius dies of the same blow that destroys liberty.
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.
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].
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I don't want free as in beer. I just want free beer.
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 :)
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.
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Knowledge is power
Power corrupts
Study hard
Time is Nature's way of keeping everything from happening at once... the bitch.
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!).
-- @rjamestaylor on Ello
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.
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 ...
flickers noticably when refresh rate is set too low
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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From: http://www.feds.com/nll_lib/ctd/ctd0706.htm
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.)
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.
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
A properly driven [read: digital] LCD, say the Apple Cinema Display, is brighter and clearer than a CRT. A good quality CRT (Sony Trinitron or Mitsubishi Diamondtron) will be the next best thing, and as far as price/performance goes, the CRT wins hands down.
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.
Specialist Mac support for creative pros, Melbourne
One thing I notice is that there's considerably less glare with an LCD screen. Possibly because, unlike a rounded CRT tube, I can find a position for the LCD which doesn't reflect the ambient light. Whatever the reason, it helps my eyes considerably.
"If I have seen further than other men, it is by stepping on their glasses." - Michael Swaine
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.
::I will not moderate my opinions for your stinking karma
I prefer my 14.1" TFT laptop screen over my 19" IIyama CRT, because it is much sharper and easier on my eyes. I'm considering buying a large TFT (18") for my regular PC, but I'm hesitating because I also want to play games on it. Is TFT suitable yet to play games or watch DVD movies ??
My experience with these devices is good, and almost everyone sells them. While you may not find them easily for larger size monitors, that shouldn't be a problem if you've been working with laptops. Or if you're not opposed to paying more, get one of the Phillips flat HDTV's. We've got one at work and it's spectacular. Expensive and not the best with every video card (we had to use an ATI to get it to work well *cringe*), but when you get used to it, it's hard to go back.
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
One factor of the issue that I have not seen addressed, is the fact that CRTs produce a whole bunch of electromagnetic radiation. I don't know how much, and it would be nice to see it quantitized. I would guess it would be a pretty large amount. I mean, think about it, the CRT is mostly a big phreakin electron gun, aimed at your head. Even if most of these electrons stay on the right side of the glass, a few must slip through. -------- Off topic: I am suprised Nikolai Tesla remained as healthy as he did when he was letting AC pass through him all the time. I think he also found X-rays to be relaxing, and would bathe in them for long periods of time. Mmm, nothing like some good eccentricity. By the way, Tesla was much more influential to today's uses of electricity than Edison was. There was actually a rivalry between the two. If you read about it, you'll find that Edison was a bastard, and does not deserve half the credit he gets in today's sad failure called "public school".
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loosing all hope is an ideal
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Incite and flee.