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  • How many of you get symptoms from flicker within a fraction of a second?

I'm similar to this. Things like OLED iPhones, modern OLED Android phones, certain monitors (not just OLED) give me symptoms immediately within seconds. Weird and uncomfortable sensation behind eyes, dizziness (but not like room spinning dizziness), foggy feeling, body warmth, sort of nausea feeling etc. It's a horribly uncomfortable feeling. LCD iPhones on later iOS versions also give me similar feelings but not exactly the same and maybe not quite as immediate. I don't seem to get the headache that many of the people here get but maybe I'm getting migraines just without the headache part. The symptoms take some time before they go away. Usually a few hours of gradually getting better.

For me I'm not entirely convinced it's pure flicker. As I've tried to figure this out I realize that many devices I've used for years have a TON of flicker and have never bothered me. And the LCD iPhones/iPads that were ruined after the iOS updates don't seem to have "flicker" in the same sense as something like PWM. I've also started getting symptoms from screens in many new cars. But I tested my current vehicles (a 2013 and a 2020) and realized that the interior lighting/dashboard and screens flicker like CRAZY. But I get no symptoms at all.

    AGI

    Interesting, I had started to wonder if maybe this was a form of epilepsy and was going to potentially explore that with a doctor.

    Did the Lamotrigine work for you?

    • AGI replied to this.

      Abeabe

      Actually, I'm reading about blood circulation and a medical/electrical concept called "zeta potential". Having poor zeta potential is indicative of circulation problems.

      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576907/

      That link is about how grounding/earthing might help with circulatory issues but make of it what you will.

      I do think getting more circulation to the head and eyes is important. Also, I've heard raisins can help with ocular issues through polyphenolic nutrients as do deep breathing exercises, etc.

      ocean10

      It seems many new cars interior and exterior lights have some sort of flicker. Been spending a lot of time trying to find or fix the right setup on this forum starting last year but from 2006 to 2013 when I was still using CRTs and an old laptop with TN PWM screen, I had no eyestrain issues. I have brought up EMFs and chemical smells (VOC, etc) in vehicles as contributors to symptoms but that is not the focus of this forum.

        photon78s I had BMW x3/x5 and now have ioniq 5. I don't have/had any problems driving those cars even with their crazy display or led interior lights PWM. I think its because i'm not focusing on display that much as when using laptop or phone screens.

          madmozg

          Not to mention that your eyes are focused mostly on the road and distant objects and when you look at the screens you shift focus to near field. This shifting does not happen as much or not at all when one is staring at the phone or computer all day. Possibly other peripheral vision, blinking rate, and convergence and accommodation factors too.

          From a brief test drive, I know some volvo xc90 heads-up display projection have significant flicker and that is always in your line of sight.

            photon78s 2017 Cadillac Escalade and 2016 Corvette z06 both have wild flickery HUD too. Even interior control lights too but I don't think I am bothered by them like I would be on a screen

              jordan

              Cool cars! I shall add that the different posture of sitting in the car and the physical and mental activity of driving itself might also affect eyestrain differently than in other contexts but this is just my hypothesis.

                photon78s agree. My 3 prev. cars all had heads up display, I had no issues fortunately.

                ocean10 For the moment I decided to not take any medication.

                The epilepsy thing...I am not the only one on this forum who got tested. From my recollection, most people tested negative. Not sure what the frequency of the trigger was in their case, though. I feel like a high frequency test has not been conceived yet. I also have no idea if a sufferer of "classic" epilepsy, e.g., from stroboscopic lights etc, develops symptoms while watching a screen as well.

                photon78s

                I recently rented an Audi Q7 and a Land Rover Defender. In both cases the screens behind the steering wheel didn't seem too bad but the actual infotainment screens in the center gave me symptoms even if just in my periphery. Became very uncomfortable until I covered them with construction paper.

                  ocean10

                  That is really unfortunate and those are also high end vehicles. Hopefully you can at least access most needed functions without using the infotainment screens?

                  I think these developments may likely bring more issues from PC and phone arena to vehicles:

                  https://www.amd.com/en/solutions/automotive/in-vehicle-experience.html (amd radeon graphics powering car infotainment include video games for car displays)

                  https://nvidianews.nvidia.com/news/hyundai-motor-group-selects-nvidia-drive-infotainment-and-ai-platform-for-all-future-hyundai-kia-and-genesis-models

                  Would be interesting to know if current displays in cars are already FRC types but it looks like the trend will continue for more and more "immersive" displays.

                    photon78s thanks! Unfortunately they aren't mine haha. I hope cars eventually eliminate bad pwm

                    4 days later

                    photon78s

                    I suspected the same thing. Was thinking that the dashboard screens behind the steering wheel potentially weren't using GPU's while the center console ones were. Might be an OLED vs. LCD issue as well since when an OLED screen is "bad" I seem to be more sensitive to it in my periphery than an LCD.

                    Every time I think I have this somewhat figured out something throws me for a loop. For example I originally thought for sure it had to be flicker that I was sensitive to. Still might be the case but it's definitely not ALL flicker. My 2020 Toyota Land Cruiser flickers like CRAZY everywhere (I'd post a video but doesn't seem to work, anyone know how to upload a video to Ledstrain?) But it also uses "old" technology since Toyota didn't update the infotainment in the Land Cruiser for many years.

                      ocean10

                      I used dropbox link for my microscope pixel flicker videos and others use imgur. Thanks for another data point. I'll have to microscope and measure with oscilloscope some infotainment systems when I get the chance. You also have to consider the shape of the waveform of the flicker. Is it a gentle slope or abrupt and how random or not it looks. These all can cause different effects. I'm thinking as well their are more reasons than only PWM, temporal dithering, OLED dips, etc.

                      3 months later

                      Seagull I saw your other posts about adaptation to devices, and I was wondering if you concluded some devices to be acceptable for adaptation if they gave you immediate symptoms? Or did you choose only devices that gave you delayed symptoms?

                        Ivan_P

                        Hi Ivan,

                        Most of the devices gave me immediate symptoms. I found I could adapt to those which gave me eye pain/conventional headaches, but I could not adapt to those which gave me migraines, immediate or not. However, my screen issues have improved massively since then and now I can also adapt to screens which give me migraines. My advice would be to experiment and see how it works for you.

                          Seagull thanks a lot for the answer!

                          What about devices that give you red/dry eyes? Have you found them also acceptable for the adaptation?

                          For me, I don't get immediate symptoms from PWM (it takes about 20 minutes to feel it), however, if a device has that specific kind of "fake 3D" feeling to its display output I get symptoms and brain fog immediately.

                          Devices with really strong PWM can certainly be really straining and painful to use for too long, like an old CRT — but… I can tell that's an entirely different kind of strain compared to the even worse type of eye pain + constant double vision that I think is induced by color and contrast post-processing that can totally disable me and prevent me from concentrating or smoothly reading, even on devices that are otherwise PWM-free.

                          I'm unsure about temporal dithering, because most screens and devices affected by dithering also have many other issues related to post-processing.

                          Even an ancient CCFL TN 4:3 monitor from 2005 I own, which also uses temporal dithering, adds really obvious "extra" white halos around all text regardless of what device is connected.

                          I definitely feel a decent bit better after disabling dithering on devices — but as long as there's no strobe-like PWM which causes its own set of issues, it really seems like it's way more about the colors and amount of post-processing that makes or breaks a screen for me (compared to the temporal element).

                          One example is my single "perfect" laptop, which still has a mild flicker depth version of PWM (looks more like incandescent flicker instead of fluorescent flicker in a slow motion video), and potentially has some pixel flicker and pixel inversion too, because it doesn't feel as still as e-ink. It's even WLED-backlit and not CCFL!

                          BUT… despite all of this… I can use that laptop perfectly with nearly no Issues, no other laptop screen I've tried yet even comes close to how good this one is.

                          When I look close up at the pixels on that one laptop —at least while running the specific Windows 8.1 version that's currently on it — it's apparent to me that the amount of post-processing is very minimal, compared to bad screens where I immediately see e.g. obvious halos, blue and green glows around contrasting objects, and "extra red color fringing" everywhere.

                          Side note, the pixels on my 2004 Nintendo DS top screen (interestingly, not the bottom screen, which does cause some mild strain) look even more "pure" and unaltered compared to the laptop! I notice essentially zero post processing or anything resembling edge enhancement on that DS top screen! However, the specific old laptop is already "pure" enough to cross that "perfect screen threshold" for me, which very few devices have achieved.

                          It really seems to be connected to the "simplicity" of the output on each, the pixels are displaying something very precise to the exact unprocessed colors that would appear in a PNG screenshot, and doing very little "extra", e.g. colors seem to not be "leaking" in a fuzzy way into nearby pixels.


                          What I think the solution is:

                          Therefore, I think the longer term solution truly lies in figuring out how to build a custom LCD controller, TCON, driver board from scratch that ensures the signal it receives is reproduced as purely as possible, skipping every possible enhancement, to the point where doesn't even do any gamma correction or color calibration —

                          (of course, also connecting it to a safe GPU, or even better having the computer just take constant "simple" screenshots like VNC and then transferring it to the controller in a different way like USB… similar to how DisplayLink works.)

                          I feel like this side of the hardware is way more important to put the effort into trying to redo from the ground up… compared to building a new type of physical pixel or backlight module, but then pairing it with a generic off-the-shelf controller board that still creates "bad output", such as dithering, inversion, messing with colors/contrast/edges, oversharpening…

                            DisplaysShouldNotBeTVs

                            Interesting proposal for what to do next. Just adding that I was experiencing problems despite using my DIY incandescent backlit panel paired with the cheap off-the-shelf DP controller board before losing almost everything including my test equipment in a house fire (lithium ion battery exploded).

                            dev