Hi
Was curious if anyone was aware of any studies on eyestrain for plasma vs lcd screens.
Is there a difference, or are other factors (brghtness of image, closeness to screen, ambient room lighting, etc) more important?

A lot things can play a role with eye strain. Motion, lighting, brightness of a display, proximity to screen, field of view, and so on.

I think that how close you sit will play the biggest part.

Hi
Was curious if anyone was aware of any studies on eyestrain for plasma vs lcd screens.
Is there a difference, or are other factors (brghtness of image, closeness to screen, ambient room lighting, etc) more important?

I've noticed more eye strain on LCDs and Plasmas compared to good old fashoned CRTs. I wonder if it's the extremely slow response time of LCDs and the mildly slow response time of Plasmas as well as huge green phosphor lag of the Plasmas that result in eye strain. On computer CRTs I get no eye strain if I run it @ 85khz, and on 60I CRTs I don't really ever get eye strain.

I've noticed more eye strain on LCDs and Plasmas compared to good old fashoned CRTs. I wonder if it's the extremely slow response time of LCDs and the mildly slow response time of Plasmas as well as huge green phosphor lag of the Plasmas that result in eye strain. On computer CRTs I get no eye strain if I run it @ 85khz, and on 60I CRTs I don't really ever get eye strain.

The flicker on CRT's was unbearable. Especially through a video camera.

I've observed that running a display too bright or too much contrast for the viewing room is hard on the eyes. It can be like trying to concentrate on picking out details in the image while a bright flashlight fluctuates into your eyes.

When someone (whoever "that guy" was) proposed that the human eye can accommodate light to dark in the millions to 1 range, flat panel displays were not what they had in mind. ;) The human eye can adjust to take a limited piecewise bit anywhere in that range at one time, but trying to "see" that kind of range on a flat panel display is really not a comfortable experience.

I don't know if this will help but I'm still struggling with my eye problems. Mine are not realted to just the TV but some interesting points were brought up here.
http://www.avsforum.com/avs-vb/showthread.php?t=1076968

I went to Lowes today and bought a 21" under cabinet light fixture and a 6500k bulb to put behind the TV and will give it a try for a few nights. I'm on some eye drops now that have helped some but the set still seems awful bright even with reduced settings.

I came from a 58" Pioneer Elite CRT RPTV to a 55" Sony SXRD and now have a 50" Panasonic Plamsa. I miss my bigger screen size but I'm struggling so bad now that I'm afraid to go any bigger. :( I still want a 58PZ800U. If I find a big sale on Black Friday I may have to bite the bullet and try it anyway. I'm still sitting 15 to 16 feet away.

Jim

From my experience, the reasons for any fatigue that can be traced to TV viewing are:

1. Watching in a dark room. The eye tends to adjust to the low average light intensity just to be whacked with a bright screen. It's like being blinded by the headlights at night.

2. Sitting too close. This leads to sensory overload, further aggravated by fast action.

3. Watching standard definition picture from a short distance. The eye is trying to adjust to reduce the "out-of-focus" perception in vain. This is why I get really pissed off when a station uses a soft lens to cover up the wrinkles on the face of an aging TV personality.

4. The idiotic technique of making action artificially more exciting by resorting to what has been called "shaky hand camera". Our brains are not used to that crap in real life.

Did I overlook anything?

A bias light might help. I'm in the process of putting my own but in reality my eyes don't get fatigued since I'm used to viewing test patterns for 10 hrs. a night when I worked on DLP's...but I'm hoping for a percieved PQ increase with the bias light.

4. The idiotic technique of making action artificially more exciting by resorting to what has been called "shaky hand camera". Our brains are not used to that crap in real life.

You are sooo right! I wish people would not only boycott movies with that idiotic kind of camera action, but there should be a Web site where movies are rated according to that nonsense. This has been my beef for years, and I finally had enough, and borrow DVDs from the library for free now instead of buying them. No way I will spend another dime and support that kind of insane "art."

There have been studies on this: http://www.advanced-pdp.jp/fpd/english.html#2

http://www.advanced-pdp.jp/fpd/img/en_027.jpg

However, I do not agree with their findings. They have all of the displays set to a peak white of 500cd/m², which is ridiculously bright. (I would actually be surprised if most CRTs/Plasmas can reach this without problems…)

Their conclusion is that the power/brightness limiter is a good thing, as it lowers the brightness to a reasonable level when the screen is supposed to be bright, therefore causing less eyestrain. Certainly, if peak white was set to 500cd/m² I would be glad of this “feature” of PDPs.

When calibrated to a brightness of 80cd/m² using a 1% window as specified by the EBU (this is actually lower than the brightness they measured for a full white screen, therefore not a strain on the eyes) things change considerably in my opinion.

I had a calibrator take measurements of a Pioneer LX5090 (UK 9G) as I didn't have access to one myself, and compared that to readings I have taken from two CRTs I have—the G90fb being an average (at best) CRT monitor, and the TX-28DT40 being a five/six-year old Panasonic CRT television that I have never considered to be that great. (I was actually expecting the monitor to outperform the television, which is why I measured it)

http://i36.tinypic.com/2nqty69.png
(note: if you use a 5% white window rather than 1% to set brightness on the plasma, it tracks almost identically to the G90fb up to 25%)

While I do not have LCD measurements here, they will be exactly the same as the ‘reference’ line. That is, the brightness does not change with the size of a white window. White is white, no matter how large an area it covers.


While this behaviour from a plasma display may be desirable in an uncalibrated state, as it means it's hard to set a screen to be too bright with bright scenes, when calibrated to a reasonable brightness, it results in the display becoming far too dim with very bright images — much dimmer than even a half-decent CRT, and significantly dimmer than a good CRT, which only loses around 5% brightness rather than almost 60%, and I find that to be a strain on the eyes.


There are other factors to consider as well. I find the flicker and phosphor trails that you get on plasmas to strain my eyes.

LCD isn't without issues either. The poor motion resolution/motion smearing makes it very difficult to track objects properly, which also strains the eyes.

Plasmas don't have great motion handling either, but it is much better than LCD. In that regard, CRT is much better than either, though the flicker of a 50/60Hz CRT is very hard to go back to after being used to PDP/LCD or other modern display technologies.

Ramazur has some good points as well, I would agree with all of those, though I do find that watching in a darkened room is ok as long as you have the display set to a reasonable level (I find bias lights to be a distraction) and you have it filling up enough of your field of view. (viewing at three screen heights is recommended)


I would say the main reason for eyestrain with these display is that they can be set to go much brighter than CRTs (even though plasmas lose a lot of brightness, peak brightness can go higher) and most people have their screens set far too bright for their viewing conditions.

As LCD can go brighter than Plasma, it's usually a lot more of a strain on the eyes if it's not set up properly. (at a proper brightness, most people think the image looks dull initially, and don't give their eyes a chance to adjust to it, turning it back up)

... and most people have their screens set far too bright for their viewing conditions.

...and they play their car radios and the MP3 players too loudly, too. If everybody would also learn how to speak at the lowest level needed to carry on a conversation we would have fewer divorces, lower delinquency and crime rates. I am digressing but I couldn't resist this one. We seem to be a society of excesses from the brightness of the TV sets to the size of our cars, loud TV commercials, flashing icons when we browse and on and on. No wonder some of us go nuts.

I had a lot of eye strain with my 650 LCD until I used CNET's settings which include brightness at 3. now it's fine, even in a dark room.