DescentBB

I just got a new monitor, Nec MultiSync 20WMGX2, and I’m finding it hard on my eyes. Everything appears glowy and its very hard to focus on the screen. I even turned the brightness to 20% and that didn't help. I never had this problem with my old Sony Trinitron crt.

Has anyone else had this problem with eyestrain with an lcd? Any Solutions?

Thanks.

Here are some crappy pics of my setup.


Pics of ghosting on screen which on my crt was almost not noticeable. The Nec has a 6ms response time which is supposedly pretty good and comparable to some 2ms monitors.

DVI or analog?

And are you running the native (maximum) resolution?

I'm using DVI-D and running native 1680x1050. Everything is very sharp and clear. It just feels like the colors are shimmering a little. But they aren't. I think my eyes are having trouble focusing. Florescent lights bother me too. Maybe it's the same problem with this type of LCD?

Up your refresh rate to 72hz. LCD's usually run at 60hz, which is the same as flourescent lights (flourescent lights kill my eyes). Your eyes operate at 60hz, and some peoplecan't take the same frequency in the hardware. I know I can't.

The max my lcd can go is 60hz My crt i was running at 80hz

are you using incandescent or fluorescent lights?

it might be a good time for the eye doctor.

Testiculese wrote:Your eyes operate at 60hz

Much as I'd like to agree with you Dave, on this occassion I believe you're incorrect

The human body operates at 50Hz - which is exactly the reason that New Zealand power (240V AC ~50Hz) is so dangerous: it causes muscles to contract and because of the frequency, if your hands are grabbing a live wire, it is impossible to let it go. At 110V AC ~60Hz (Like you guys sensibly have!) then you could let go of the live wires.

Eyes operate at the same frequency.

What he may be seeing is some effect of the harmonic of 60Hz not being perfectly in-sync with the lights. That could cause eye strain of some type.

I hate to say it Cyclone, but I think you should have researched the unit more before buying. All LCDs should have at least 72Hz available in refresh rate - 60Hz is useless for anything which requires frame rates: the monitor is very limited to low data rates at 60Hz. (It may give the illusion of smooth, non-jerky movement, but gaming requires more than the illusion.)

50? Oh ok.

If that's the case, then why do florescents bother me so much?

Mobius wrote:The human body operates at 50Hz - which is exactly the reason that New Zealand power (240V AC ~50Hz) is so dangerous: it causes muscles to contract and because of the frequency, if your hands are grabbing a live wire, it is impossible to let it go. At 110V AC ~60Hz (Like you guys sensibly have!) then you could let go of the live wires.

Wow. That much inaccuracy from Mobi

ELECTRICITY-PHYSIOLOGICAL EFFECTS wrote:Relatively low currents can cause muscular contractions that may prevent a victim from letting go of an energized object. The threshold of this current is a function of condensity, contact area, contact pressure and individual variations. Virtually all men and almost all women and children can let go at currents up to 6 mA. At 10 mA it has been observed that 98.5% of men and 60% of women and 7.5% of children can let go. Only 7.5% of men and no women or children can let go at 20mA. No one can let go at 30mA and greater.
[..]
The frequency of the electrical signal responsible for electrical accidents is generally known. In Europe, it is almost always 50 Hz and in the Americas, it is generally 60 Hz. In rare cases involving railways in countries such as Germany, Austria and Switzerland, it may be 16^(2/3) Hz, a frequency which theoretically represents a greater risk of tetanization and of ventricular fibrillation. It should be recalled that fibrillation is not a muscle reaction but is caused by repetitive stimulation, with a maximum sensitivity at approximately 10 Hz. This explains why, for a given voltage, extremely low-frequency alternating current is considered to be three to five times more dangerous than direct current with regard to effects other than burns.

See http://www.ilo.org/encyclopedia/?doc&nd=857100207&nh=0

Besides that, your eyes operate analog. So does an LCD BTW -- the background light is steady, so is the picture when there are no changes. There are no interferences w/ fluorescent light unless the picture changes constantly at 60Hz. If he sees stuff w/ a steady LCD picture I would indeed recommend a visit to the doctor. Ghosting happens when there's a change in the picture and is caused by the time the crystals need to realign themself to the new condition.

Edit: I hate fluorescent light as well, makes me edgy. Possible explainations:

Fluorescent lamp wrote:Many people find the color spectrum produced by some fluorescent lighting to be harsh and displeasing. It is common for a healthy person to appear with a sickly bluish skin tone under fluorescent lighting. This is due in part to the presence of prominent blue and green lines emitted directly by the mercury arc and in part to the type of phosphor used. Many pigments appear a slightly different color when viewed under fluorescent light versus incandescent. This is mainly the case with fluorescent lamps containing the older halophosphate type phosphors (chemical formula Ca5(PO4)3(F,Cl):Sb3+,Mn2+), usually labeled as "cool white". The bad color reproduction is due to the fact that this phosphor mainly emits yellow and blue light, and relatively little green and red. To the eye, this mixture looks white, but light reflected from surfaces has an incomplete spectrum.
[..]
Fluorescent lamps do not give out a steady light, instead they flicker (fluctuate in intensity) at a rate that depends on the frequency of the driving voltage. While this is not easily discernable by the human eye, it can cause a strobe effect posing a safety hazard in a workshop for example, where something spinning at just the right speed may appear stationary if illuminated solely by a fluorescent lamp.

And of course the interference w/ CRTs.

See http://en.wikipedia.org/wiki/Fluorescent_lamp

Edit2: maybe the reason for the strain is a broken backlight -- if you "drag" your eyes quickly accross the picture, do you see a stroboscope effect ? If so, return the monitor and get a replacement.

It should also be noted (IIRC) that most florescent light fixtures these days use transformers to drive the lamp somewhere around 10,000 to 20,000 Hz so replacing an old fixture will often eliminate the visible flicker from a florescent lamp, it will not correct the poor color range from the lamp though.

Thanks for the replies.

Ok. So this is very hard to explain. Have you ever looked directly at a black light? Well my eyes kinda feel the same way after looking at my monitor for a few minutes but not as bad? My eyes just feel strained and everything appears to shimmer a little bit making it hard to focus on anything but at the same time everything looks sharp and not blurry. Maybe a good way to expain it is if you look directly at a light bulb and turn it off while still looking at it there is an after glow. And yea I tried turning the brightness down.

The blue text on the black background of the dbb is really hard on my eyes. The blue text seems to glow and the edges kinda shimmer?

On my crt anything lower then 80 hurts i could notice flickering and my eyes were only tired after staring at the screen with no brakes after 8 hours. I don't notice any flickering on this lcd.


I tried moving my eyes across the screen while looking at a white background and I did notice very faint curvy lines on parts of the screen out of the corner of my eye but when i tried to look at them they would dissapear? It could be my imagination though. I noticed that when I manually adjust the focus on my camera and take a picture I can really see these curvy lines. Maybe it’s the polarizing filter on the lcd panel? I don't notice this affect while looking at the screen but my camera sure does?

moire pattern...

try moving the speakers somewhere far away.

That kind of pattern should never show up on a LCD, especially one running on DVI, make sure it is tuned to digital input, if you don't even have an analog VGA cable connected it should be fine. And magnets shouldn't have any effect on a LCD at all.

yea. using direct dvi, no vga converter. That pattern only showed up when i tried to focus my camera right at the screen.

I dunno. I'm probably going to return it and take a look at other lcds in stores.

Does anyone know of very high end graphic lcds that have very good colour gradients and white color? Maybe one with a 80hz refreshrate if that's what my problem is?

If you have a DVI-I (or even a DVI-A) cable and the monitor may be picking up the analog signal from it. If so, there should be a setting on the monitor somewhere to select the digital signal. Or try a DVI-D cable.

Viewsonic Pro series has very good color reproduction and goes up to 75Hz.

Krom wrote:It should also be noted (IIRC) that most florescent light fixtures these days use transformers to drive the lamp somewhere around 10,000 to 20,000 Hz so replacing an old fixture will often eliminate the visible flicker from a florescent lamp, it will not correct the poor color range from the lamp though.

Transformers don't do anything to frequency, they change voltage and current.

Where are you guys getting this nonsense that the human body operates at 50 Hz? Last time I chacked, I didn't have a magnetic generator spinning around inside me, chemical reactions give rise to direct current, not alternating .......

Cyclone
Try playing with the light in your room. When i feel like my moniter is giving me eyestrain - i turn on the room light, so the room around me is brighter and it feels less like i'm staring into a laser beam.

Also, try sitting further away from the screen. when i see your desk i think \"hmm, that screen is pretty close to your face\"

Yea someone else suggested shining a desk lamp at the monitor. This actually helped but not to a degree that felt comfortable in using the monitor.

The screen is 22inches from my eyes. My crt setup it was 20inches from my eyes. In the manual they said the best distance was 20inches.

Oh well. Thanks anyways. Hopefully I can find a solution.