Yeah I wish we had the organization to do some more objective testings. It's a few years of anecdotes and opinions that we are trying to kludge together into some solution.

Both new SW on older HW AND old SW on newer HW lend credence to the "make things pretty with flickering" idea being a problem. The former because the HW can't do those pretty things to the degree the SW asks, and the latter because the SW isn't asking the HW to do them. But without some controlled testing who knows? Also we have seen dithering on the Dasung panels so we know its happening, just not if its the problem since we cannot turn it off.

So far every time I swore I had solved it for myself there was an example proving it wasn't the issue...like with PWM. So until we can definitively swtich dithering on or off I don't see how can know...and I've not heard any other plausible theories put forth so far. It's so incredibly frustrating not having ANY solution that works for even a number of people. It's just unexplainable single cases at this point but symptoms are so similar it HAS to be rooted in a similar cause.

In my experience and for my eyes, yes the facts are simple: CCFL is always good, LED is always bad.

For the past 20 years (working a minimum of 8 hours every day, stylesheets, coding, photo, video):

CCFL: desktop, laptop, Windows XP to W10, Linux Mint or Ubuntu => no problem, no strain no headache. And my old CCFL screens do flicker a lot and it's not a problem (though CCFL flickering is "softer" than LED flickering).

LED: smartphone, external monitor, laptop, TV, same operating systems (Windows, Linux), Low Blue Light, Flicker Free, Asus splendid blue light filter, Android filter, Windows night setting, Iristech software, all kinds of settings, low saturation, low brightness, zero contrast, ...
=> immediate pain, headaches, brain pressure, heart beat too high, etc...

In fact, contrast, brigthness, ambient light don't matter with CCFL. Even with not-so-good settings and a bad environment, CCFL do not hurt. While LED, even in a perfect environment with fine tuned settings always hurt.

So I still don't know what it is but I can draw a practical conclusion from that: LED is bad for me, no matter the software or hardware around it.

There must be something else "in" LED light, something beyond blue light.

    2 years later

    Alexandre Alexandre, VA is a significantly different panel technology. I'm testing out a unit that has ghosting just dragging windows and scrolling through text. My question to you is if you've tried a VA panel and had the same lousy experiences you've had with IPS screens. Agreed LED isn't ideal, but VA seems to allow one to use the screen with less exposure to the backlight.

    Edit: just read your profile and see that even VA doesn't work for you.

    So why is it so difficult to find new CCFL units? Why can't manufacturers make just one current generation unit with CCFL backlighting for niche users like you? What is it about LED that has manufacturers believing it should completely phase out CCFL? After all, we have TN, VA, IPS, and the consensus is that each panel type has its strengths and weaknesses and warrants production for different users.

    Edit 2: the ghosting experienced is only when my Ubuntu Night Light is enabled at a strong warm setting. Not sure why that makes the ghosting noticeable when dragging windows and scrolling, but the problem seems solved when I disable it or when I make it less strong. For what it's worth, I quite like the Ubuntu Night Light feature in manual mode where I can enable it and disable it any time, and slide the Color Temperature from less warm to more warm as I see fit.

    For reference, even on the warmest Color Temperature in Ubuntu Night Light, my IPS comparison model exhibits no ghosting during the same activities.

      11 days later

      NightWolf149 , I also have a bad experience with GW2255. Within seconds I feel eye pinching sensation and some kind of numbness in the brain. I noticed this an year back as well as again a week back. In between, I tried a couple of Dells.

      BL2420PT does not present such problems for me. Although its supposed to be flicker free and true 8-bit, I do not seem to have benefited by it, with respect to avoidance of strain.

      I use KDE Plasma on Arch LInux.

          ravipra Why might the GW2255 cause pinching and brain numbness? And why do you think the BL2420PT is better?

          I had a look at reviews and don't see anyone else complaining of eye or brain issues with the GW2255. From users, it reviews very well.

          One returned the 27" WQHD version of the BenQ IPS, saying:

          I realized in the first minutes using this that the text in the screen was blurry, tried every configuration but no success. I had to return it to the store. If you're going to code or must see small text in your screen, I don't recommend this.

          I recognize at the GW2255 price point users are bound to be less picky, but if they were getting pinching and brain issues I should be able to find an anecdote or two, so I'm wondering what about that unit triggers those symptoms in you and in the original poster. Most don't seem affected.

              K-Moss, I am not sure, really! I bought GW2255 after reading several reviews. One difference, though, is that it does not support displayport, so used VGA. The other 3 monitors (2 Dell and 1 BenQ) support displayport.

                4 days later

                Hello people, i wanted to update this post since i received email that you brought it back from death and i'm glad you did since i forgot about it. 😃
                So for the past 2 years for my PC i am still using DELL E198wfp and my eyes didn't got worse from it at all it's been stable....but i still have BenQ GW2255 (my sister is using it) and she also had said to me that her eyes hurt from it and she is using it only for 2 months. There is definitely something wrong with that monitor because i have used it also when i was installing windows on my sisters computer and for those 30 minutes i had eye pain,eye dryness and headache which i don't have when i am using old DELL CCFL monitor. On my old Dell i can play games for hours and everything is ok.
                BUT KNOW I HAVE SOMETHING REALLY INTERESTING!
                2 Months ago i have bought 2 LED 55" Smart TV's,one for myself and one for my parents but they are not the same.
                Mine is SAMSUNG with VA panel and PWM flickering and the other one is LG with IPS screen (don't know if LG use PWM)
                And what i have noticed is that i can watch my Samsung normally like i can my Dell monitor but if i try to watch LG TV from my parents after only 20-30min my eyes get dry and start to hurt, I will continue to use my TV and try and see if it will hurt me later but for know it doesn't but i am using it only for 2 months and not very often so i can not guarantee that it is good. Also one interesting fact is that BenQ monitors are using LG panels and they hurt my eyes like LG TV does, no matter if it's VA or IPS, while Samsung does not, at least for know, even while it's VA panel and it even has PWM flickering and i am not using it at 100% brightness. My old Dell monitor also flicker but for me that doesn't present a problem,something else does and i still don't know what it is.

                  NightWolf149 Which panel is in the BenQ? Do you know exactly? And I'm surprised it makes no difference for you whether the panel is VA or IPS, just the whether it's LG or not. According to some, LG does have a history of using the cheapest possible junk, but that BenQ you say is problematic tends to review very well.

                      K-Moss BenQ GW2255 has VA panel,but i also used GW2406Z which was an IPS,that one was maybe a little bit better but it was still very bad, i don't have it anymore,i have sold it 2 years ago but i still have GW2255, my sister is using that one.

                          K-Moss From the day i sold my GW2406Z i didn't bought any LED monitor, i was too scared. I am using old 19" DELL E198wfp, i had plans to buy DELL Ultrasharp monitor (U2419H) since i am using old DELL now without problems for 2 years.

                            NightWolf149 i used to think it was all about PWM and flicker but for me its not. Its the screens native contrast ratio. Ensure the screen has a ratio of less than 1000:1 ( my sweet spot seems to be 850:1). Most Dell screens are about 600:1 which is great. the BenQ GW2255 has a ratio of 3000:1 and Dynamic ratio of 20million :1 which is disgusting eye poppingly dangerous. Hope this helps as its taken me about 26 years to figure this out and cost me a lot of money buying and then having to sell screens, TVs and mobile phones.

                                dell U2419 has a contrast ratio of 1150:1 so you might be ok but i personally wouldn't chance it. If you do get it let us know if its ok 😃

                                But wait,....GW2406Z has only 1000:1 and that was also bad for me and my current DELL e198wfp has also 1000:1 and that one is ok. Am i missing something?

                                it could be a Hz issue. I can't look at TVs with a 120Hz panel but 60Hz is fine. The GW2406z is 75Hz panel and the Dell is 60Hz. Also the Dell has anti glare coating which may help. Reflections can be really aggravating for me. Its a possibility. Also turn sharpness down if that is an option on your monitor.

                                Actually BenQ GW2406Z was 60Hz and my current Dell is 75Hz....but interesting thing is that all off the people are complaining at discomfort but my main problem wasn't that, my biggest problem is that my vision got worse permanently after using LED monitors....i am bothered by discomfort too but CCFL monitors didn't ruined my vision while BenQ LED did. I still need to try other ones but for now i am using 60HZ 4K Samsung TV with VA panel and it's ok for now, i don't feel imidiate discomfort like i did with BenQ monitors and my vision is still stable.It could be something whit backlighting,my TV is Edge lit while BenQ monitors and LG TV which i also have and which i also can not watch for long is direct lit.

                                DiscoDave So your experience contradicts those who find VA panels more comfortable than IPS. VA always has native contrast of at least 3000:1. You've never found a VA panel that works for you?

                                  I have Acer nitro laptop with IPS panel and it has 600:1 ratio and I can stare at it all day. I did have a VA panel in my Samsung eh5300 TV and loved it but sadly broke 🙁

                                  NightWolf149 I will add my experience... Lately I wanted to play assetto corsa on my 49 SONY 4k TV and after 30-50min I was getting INTENSE pain between eyes and later on headaches which lasted for 1-3 days just after that shor gaming time... I really wanted to play this so I tried couple of times witch changing contrast, balance white/blacks and other settings and different game FOV, settings etc. which always ended with symptoms...
                                  One time tho it ended with vision change in left eye I was scared like you then thought I will have to go to a hospital. I quit the screen right now and went outside... still vision was same. Fortunately for me after like 40mins outside it went to normal but thats a warning: IT'S DANGEROUS , DONT PUSH... 🙁
                                  Really hoping it will get back for you stay heathly guys!

                                    dev