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Index > Heap > Do LCD monitors really save your eyes?

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proveren



Joined: 24 Jul 2004
Posts: 68
Location: Bulgaria
proveren
I just recently paid 180 euros for a 17 inch lcd monitor (second hand), hoping to save my eyes since I am starting university right now and I would have to spend much time in front of my computer. However, my eyes still get tired after the same amount of time in front of the CRT montor, or even sooner. Reaction time is noticeably slower, 3D games are disturbing to play due to the slow reaction of the pixels. While people say that there is no radiation in the lcd, doesn't the slow reaction harm the eyes just as bad by teasing them?
Post 01 Sep 2005, 13:42
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comrade



Joined: 16 Jun 2003
Posts: 1137
Location: Russian Federation
comrade
maybe the resolution is too small
Post 01 Sep 2005, 14:10
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Artlav



Joined: 23 Dec 2004
Posts: 188
Location: Moscow, Russia
Artlav
180Eu for 17 inch LCD???
I got one for ~2000$!
Post 01 Sep 2005, 14:13
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UCM



Joined: 25 Feb 2005
Posts: 285
Location: Canada
UCM
I dont find that it has a slow reaction - plus, they're more useful for me (cause i like being perfect to the 1th pixel which is harder with a CRT.)
Post 01 Sep 2005, 14:21
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bogdanontanu



Joined: 07 Jan 2004
Posts: 403
Location: Sol. Earth. Europe. Romania. Bucuresti
bogdanontanu
It is another technological Myth's area Wink

LCD save your eyes by the fact that once establised on screen the image is static . So, unless there is an animation on screen you always see the whole image. This mostly helps the brain because it perceives the other objects in the world in the same way. It helps the eys only a little by the fact that the light intensity is constant and not having huge spikes like in CRT. This somehow helps eye's focusing.

The CRT image is actually just a single dot moving over the screen in an orderly fashion. It hurts your eye in 2 ways:
1)The brain has to integrate the image "in software" and depending on your brain's "speed" and "power" you might get tired of doing it all over again.

2)To get overall intensity hummans adjust the intensity of the single "dot" / beam up to huge levels and in fact this spike of light can make trouble to your eye receptors.

But the main problem of the CRT is the fact that it does emit a lot of radiations right into your face/head.

The CRT monitor emits a lot of radiation because it has a an electronic beam hitting an metal grid (for color CRT at least) and this is the standard Roentgen radiation emission setup.

The CRT is also bigger and heavyer and consumes more electric power.

However there are many disadvantages of the LCD also:

1)The colors are very far away from perfect or professional. In fact typesetting and color calibration can be done only with CRT monitors.

2)It has a fixed native resolution and much too aften this is fixed way too big for the sizeof the monitor. This is forcing the eye to adapt to very small dots with little light intensity and too far away relatively... this generates eye strain.

3)It has an perception angle... (and a relatively small one compared with CRT) The image intensity changes by the angle...this is a very un-natural behaviour that again generates eye straing and astigmatism.

4)it does not emit light in the pixel's point ; instead it lets light pass thru from behind... The maximum intensity is limited. And the emited light is strongly polarized and thus unnatural and hard to perceive by eye detectors.

5)Its speed of image/pixel change (refresh) is PATHETIC.

Basically a CRT can change each adiacent pixel at MegaHertz speeds but a LCD can only do it every 7-12ms on average... this means arround 100Hz. because of this fast changing or moving images leave trails.


Playing games that change the screen a lot (FPS, 3D) is not for the LCD Razz static pictures on screen it is ...

6)AFAIK the chemical materials inside the LCD (the switching liquid crystals inside) are toxic... so toxic that a break/leak could kill you and hummans near you easy ...
Post 01 Sep 2005, 17:25
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bogdanontanu



Joined: 07 Jan 2004
Posts: 403
Location: Sol. Earth. Europe. Romania. Bucuresti
bogdanontanu
Ooops, how is it possible to pay 2000$ for a 17inch LCD?

... was it gold plated?
Post 01 Sep 2005, 18:17
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proveren



Joined: 24 Jul 2004
Posts: 68
Location: Bulgaria
proveren
wow bogdan thanks for the reply, very thorough.
2000$? Prices on ebay are around 200-250 euros for a second hand lcd monitor (around the same price are new ones, too). MIne is philips, has DVI, however it has one dead pixel (another disadvantage of LCD monitors), and no warranty.
Post 01 Sep 2005, 19:10
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Artlav



Joined: 23 Dec 2004
Posts: 188
Location: Moscow, Russia
Artlav
Hm. But i bought it about 5 years ago.
Post 01 Sep 2005, 19:33
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Hicel



Joined: 09 Sep 2004
Posts: 55
Hicel
Quote:

bogdanontanu:
6)AFAIK the chemical materials inside the LCD (the switching liquid crystals inside) are toxic... so toxic that a break/leak could kill you and hummans near you easy ...


I opened my LCD to repair it.. well I touched the foil more than once.. just a year ago .. Am I going to die now??
Post 02 Sep 2005, 00:48
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Matrix



Joined: 04 Sep 2004
Posts: 1171
Location: Overflow
Matrix
hi
lcd tft s around here are about $300-$500
for a 17" 16ms response time samsung super monitor


hm,
well as far as i know in lcd tft the background lights could be the only thing that can hurt your eyes, if it emmits radiations below 400 nm (UV, gamma, röntgen) but i think we can hope from a $1000 monitor to disallow the UV, Röntgen radiations to viewers eyes. ;>

so i recommend buy one not too cheap, look for some quality instead.
i think the primary advantage of LCD TFT is not its price.
Post 02 Sep 2005, 01:28
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comrade



Joined: 16 Jun 2003
Posts: 1137
Location: Russian Federation
comrade
i bought mine ~2years ago and it was for around $400
Post 02 Sep 2005, 03:17
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bogdanontanu



Joined: 07 Jan 2004
Posts: 403
Location: Sol. Earth. Europe. Romania. Bucuresti
bogdanontanu
Hicel,

Nope, touching the foil is no problem... however if it breaks into pieces and the liquid spills out in some eye detectable quantity then I would not put my hands into it... neither breathe too close... in fact I would leave the room at once and let somebody else in there Razz
Post 02 Sep 2005, 06:03
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f0dder



Joined: 19 Feb 2004
Posts: 3170
Location: Denmark
f0dder
Bogdan, sounds like you've only used very old TFTs?

It's true that they're slower and don't have as good contrast and brightness as CRTs, but current 8ms models are quite fine enough for games and movies - I don't have any ghosting on mine. (I can, however, see that intensity lowers if move a bright-on-dark window around with "show contents while dragging window" enabled, but this doesn't seem to affect games or movies).

Don't be fooled too much by the low-ms (ie., fast) TFTs - some 8ms TFTs are worse in use than 12ms because they have worse brightness, contrast, etc.

I find that switching to TFT monitors have put loss let strain on my eyes. You do need to buy a decent quality one though, or you risk having a fuzzy image, or a way too sharp image that's hard on the eyes. Also the physical size versus resolution is important - 17" at 1280x1024 seems to work out nicely for me (remember that TFTs have larger viewable area than a CRT of the "same" size).
Post 04 Sep 2005, 04:09
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bogdanontanu



Joined: 07 Jan 2004
Posts: 403
Location: Sol. Earth. Europe. Romania. Bucuresti
bogdanontanu
f0dder wrote:
Bogdan, sounds like you've only used very old TFTs?


No, i have used all sorts of TFT's old and new. I have 2 somehow old laptop's TFTs and a new 17inc Samsung TFT and another very new 17inch TFT; in time I have used many other models.

The problems with TFT's presented here are conceptual ones.
The producers try to improve those issues with every now models but some of them might never get improved (like the fixed 1 native resolution issue).

I have consciently choosen to use TFT's because of their non-radiation emission... but that does not mean that I also have to blur my "mind eyes" and stop "seeing the truth" just to make my choice look good.

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Post 04 Sep 2005, 14:14
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