The primary monitor I am able to use successfully is an Asus VS247H-P (23.8" 1080p TN panel) monitor manufactured in July 2012 (the manufacture date is marked on the back). Since I've had such a problem finding monitors that don't trigger my eye strain symptoms over the past ~8 years, I had purchased two backup copies of this same Asus VS247H-P model: one copy manufactured in January 2015, and one copy manufactured in August 2018.

The Asus VS247H-P copies built in 2012 and 2015 cause me no symptoms, I can use them for 8 hours a day no problem. But I discovered that within 10 minutes the Asus VS247H-P built in 2018 causes the serious eye strain symptoms that I experience with all modern monitors! What's more, the colors of the 2018 Asus VS247H-P are noticeably more vibrant than the other two, even though the monitor is the same exact model and specs on paper.

I intend to keep digging to see if I can determine what changed- because whatever they changed causes my eye strain symptoms! I currently suspect the broader color profile somehow enabled in the newer copies is achieved by dithering (as I have also experienced my symptoms with non-LED flickering projectors). But meanwhile just felt it was worth mentioning in case it helps anyone that even within the same model# the technology has changed.

    Gemsand

    TN panels are normally 6-bit and use dithering to achieve 8-bit, it would be somewhat special for a tn to be natively 8-bit and not need to dither (though it probably would still dither). So I suggest looking elsewhere for differences between your two monitors.

    Perhaps try to research what model the panel itself is? Monitor manufactures typically do not make the panel itself and buy these in from a third party, so its possible the model of the panel changed in the newer version.

        Seagull

        The spec sheet for this monitor has always been 6 bit + FRC to get 8 bit color- which I expect means it has always had some dithering. This is the main reason I discounted dithering as the cause of my symptoms for so long. Yet now, in the newer 2018 copy, the color is so much more noticeably vibrant. If some new type of dithering isn't the cause, I'd be super interested to understand what it is.

        I like the idea of figuring out which panel the different copies use- though I'm currently not sure how to do that without damaging one of the good copies through disassembly (I strongly suspect any spec sheets will likely all still say the same panel for that model number). Determining the panels somehow though does sound like a logical next step. Thanks for your valuable thoughts!

          Hi @Gemsand , why don´t you try to compare both monitors with an spectrometer?, to detect the difference in the light emission.

          One of my good monitors is a Dell U2720Q produced in August 2021 and I recently got another produced in May 2023 and this thing burns my eyes even on very reliable safe GPU like the Quadro K4200, pretty sure its a completely different panel since the way the image is presented is completely different looking.

          It's almost certainly down to the different characteristics of different panels used.

          Identical models of devices can be completely different internally an use completely different parts. This is incredibly common in the smartphone world, I have disassembled two "identical" smartphone models and could see the different manufacturers of the components printed on the chips.

          5 months later

          @Gemsand How is your search going? I read through your entire posts on your search for a monitor you can tolerate. I am in the same boat! Ordered the monitors you can tolerate but they sent me a 2019 version instead. Will keep looking.

            From what I remember there can be two major culprits to the "different copy of same device causing issues" situation.

            1) Internal components being quietly swapped with different models, while the model number of the product is the same.
            2) Per unit variance of the internal components, which can be explained by quality control (or lack thereof)

            Also if there's internal firmware used for any image processing or similar, a differing firmware version could impact the resulting image output.

            So what to do what about it? Maybe consider negotiating with your work if you could buy some monitors off them?

            kgharvey

            Unfortunately my monitor search has come to standstill: I have still not found any modern computer monitors I can tolerate. I do keep trying.

            I will say in my own case I feel I have narrowed down the primary cause to flickering (not too big of a surprise there for many here but I'm glad to narrow it down). What gave that away for me was I tried to use an incandescent bulb projector that used pixel shifting to achieve 4K resolution, and that flicker caused the same symptoms.

            (On a different topic- Right now I am actually dealing with the same issue in a new format: I recently bought a new car and the LED headlights cause the same symptoms! I am now trying to figure out how to replace the headlights, or I will have to sell the car and buy one that uses older headlights! This problem can be very frustrating!)

                Gemsand

                You sure it’s the lights and not the displays in the car? I’m noticing that in a lot of new cars the screens give me the same symptoms as most (all?) modern monitors. I rented a car recently where the screen behind the steering wheel (with speedometer etc) seemed okayish but the center infortainment screen was giving me symptoms even with it just in my peripheral vision.

                    ocean10 carplay seemed to really bother my eyes compared to the plain OS on the radio screen.

                      9 days later

                      ocean10

                      Yes, in my case with my current vehicle (a 2024 Mazda 3) I am sure it is the headlights and not the internal displays. They affect me within seconds, even just the light bouncing off the road! I have been investigating options to change the headlights (with both a knowledgeable aftermarket parts mechanic and also my Mazda dealership) but because the bulbs are integral to the headlight assembly, and because the headlight assembly apparently has a computer in it, there appear to be no options to change it. It seems to me there's got to be a way, so I am going to keep digging.

                        It's a shame that your 2018 monitor is giving you symptoms. Today I've been experiencing some problems with my Hisense TV that was made in 2018. I've been using it for 3 years nearly daily sometimes for many hours to watch films. I've driven it with my good laptop at 720p resolution with a refresh rate of 59hz. It is very comfortable at 720p.

                        But today I changed its resolution to 1080p 60z (its native resolution is 1080p 50hz) and symptoms began automatically. I then changed the refresh rate to 50hz and then it was much more comfortable to look at. I then watched Netflix for several hours and the picture at 1080p seemed more clear, detailed and vibrant than at 720p, but it was uncomfortable to look at when it was on this 1080p resolution and sometimes it gave me this pressure in the chest and a bit of a headache.

                        I'll try a film with VLC in the next few days to see if it's a Netflix problem, but I've used both Netflix and VLC on this TV at 720p with no symptoms at all for 3 years, so I think I have some problem with the TV's 1080p resolution. I hope the symptoms are simply stemming from what seems to be a bit of lag from using an Ideapad that has a very weak GPU and probably can't drive the TV at 1080p very well.

                        Some people here at ledstrain have had laptops that they can't use at the native resolution but they can use them at a lower resolution. I'm experiencing the same thing with my TV.

                        Anyway, I'm hoping that merely switching the TV back to 720p will bring things back to normal.

                        UPDATE: Changing the resolution to 1368x768 (720p) at 59.88hz makes the picture completely comfortable to look at again. On 1080p the picture was a little clearer and there seemed to be more depth to the backgrounds, but 720p looks just as good otherwise.

                        If anyone is having issues with their 1080p TVs or monitors, you could try changing the resolution to something like 1368x768 to see if the picture is more comfortable.

                          orangepeel On 1080p there seemed to be more depth to the backgrounds

                          this is usually an indicator that something will cause strain (which was true in your case since 1080p caused strain) because TV screens are physically flat — if you percieve "3D depth" that's very frequently an indicator of pixel flicker that is confusing your eyes into percieving depth even though there physically shouldn't be any.

                          EDIT: it's not just pixel flicker. It's very likely an intentional technique. See https://ledstrain.org/d/2686-i-disabled-dithering-on-apple-silicon-introducing-stillcolor-macos-m1m2m3/1283 and my other replies after it

                          a good rule of thumb is that in a lot of cases, whichever configuration gives the most "flat/2D" image is the best.

                          on the most comfortable screens i've ever used (for example, the 2004 Nintendo DS), even totally 3D games will look like a "flat projection" of the 3D environment instead of giving me any false sense of depth.

                              nothing to do with the LCD panel itself.

                              the newer screen simply has a new timing control (TCON) chip, which is likely programmed to time signals to individual pixels differently.

                              DisplaysShouldNotBeTVs Thanks for your input. I think you're right. There's some sort of pixel flicker or dithering or something tricking me into thinking there's a powerful vibrancy and depth. My mum didn't actually experience any symptoms when watching at 1080p, but I did.

                              Do you have any idea as to why this occurs on 1080p resolution but not at 720p?

                                  orangepeel Do you have any idea as to why this occurs on 1080p resolution but not at 720p?

                                  one possible theory is that maybe the scaling algorithm that is used to upscale 720p to 1080p is performance-intensive for whichever chip is in the TV, so the TV disables some other elements of the post-processing chain (such as FRC dithering) when it's not running at native resolution in order to have enough performance left to be able to upscale 720p without too much latency

                                  that's just one theory though

                                    2 months later

                                    I previously used a monitor model similar to the OP (although with an IPS panel) for several years without issue. In my case they were two ASUS VS239H(-P, I think) manufactured in 2015. This monitor uses the LG LM230WF3-SLN1 panel.

                                    After buying a Dell E2416Hb monitor and replacing the AUO M240HTN01.2 panel with a new one (this panel is apparently still being made), I determined that I was getting bloodshot eyes after using that screen for extended periods. I recently reverted to my ASUS VS239H, and so far, so good. Interestingly, the LG LM230WF3-SLN1 in my ASUS monitor is listed by Panelook as having true 8-bit depth, although DisplaySpecifications says 6-bit+FRC so I'm not sure. It was not a particularly high-end or expensive monitor.

                                    The Dell monitor felt comfortable at first (especially the backlight tone, which seems to be my main issue), so I really wonder what else is going on with modern panels that bugs me, whether flickering or otherwise. The other possibility is that I may have "good" screens going "bad" due to environmental factors or issues with the input quality. More on that later…

                                    dev