MagnuM I get a sharp pinch in the center of both eyeballs, feeling like it's coming from the back of the eye. If I continue to look at the display, this sharp pinch will seemingly travel "into" my head towards the back, as if they were rods. If I continue to ignore this, and continue looking at the display, I will then have very sharp pain in the eyes, center, and back of the head, as if I'd been skewered by rods. This is a sharp and intense headache that can last for days before finally settling down. It feels like my brain is "fried" in this state, as if the visual processing center is totally overwhelmed.

Yup. I know what that's like. That happens mostly with PWM for me.
Actually, once eliminating PWM, eliminating dithering helped a lot. Dithering is a slower process that affected me to a lesser degree for a shorter period of it, but similar "brain fried" feeling.
You might not like seeing red, but I've found setting all monitors I get to the "warm" setting can help.

      MagnuM
      Fun to try new things. I read a review of this TV, here is an adjustment you can make: "To enable Chroma 4:4:4 support, first go in the 'General' menu, then enable 'HDMI ULTRA Deep Color' for the HDMI port that you are using. After, change the input icon to PC in the 'All inputs' menu, accessible thru the remote input button." Note that this chroma of 4:4:4 will be 60 hz not 120 hz, which is fine if your video source is 60 hz. The TV also should not be in HDR (high dynamic range) mode as chroma 4:4:4 will not work in that mode, and will instead revert to 4:2:2, etc. I would also disable motion interpolation by changing "trumotion" away from "user" (which turns it on).

          MagnuM Did you test the TV for PWM yet? This would be very interesting. If OLED TVs use low frequencies like current smartphones do (240 Hz), it should be very easy to detect with any digital camera or smartphone/tablet camera. Maybe there is a brightness level which doesn't use high amplitude PWM but only the 60 Hz low amplitude flicker that might remain when PWM is off (like on the OnePlus 3 or the Galaxy S7 with PWM-free custom kernel).

              Slacor I'm sure PWM doesn't help much, especially on an LED, but I have my Dell U2410 on 0% brightness, which means maximum backlight flicker, yet it doesn't seem to bother me (perhaps from the fact that fluorescent lights "glow" a bit from the "off" mode of the PWM duty-cycle). Detecting PWM flicker was always easy with the pencil test, or even recording the screen with my iPhone 6S+ on "SLO-MO" video mode. Are there similar easy methods of detecting this second form of flicker in temporal dithering? How would I be able to tell if the new OLED TV has dithering?

              What's interesting about the color of my Theraspecs lenses is, if you set f.lux to a low-enough Kelvin level, the screen almost looks the same as if you were wearing the lenses! That must mean FL-41 is quite good at subtracting blue light from the visible spectrum! It's always been a good tint for migraine sufferers for many years.

              Sunspark I don't know what "Chroma" is exactly. All I know is that I sensed inconsistent frames when it came to the actual motion of video itself. I chalked this up to that MotionPlus or MotionFlow artificial algorithm that would make movies look like a soap opera. I can't stand this mode. When I bought a Samsung 40" TV in 2008, this mode was turned on by default, and it gave me nausea or motion-sickness, as my brain knew it wasn't real. Once I disabled this mode on my Samsung, that nausea went away and never came back.

              What is 4:4:4 versus 4:2:2? Is that talking about frame "judder"? The whole 60 Hz versus 120 Hz deal? I must be a bit behind in my research! I think I also did have that TruMotion turned off, as from my experience in the paragraph above

              KM Aside from the "pencil test" or recording the screen with "SLO-MO" mode on my iPhone 6S+, both of which I have done, I have not seen any evidence of a PWM-flicker myself. As earlier stated, I am sensitive to both PWM LEDs and PWM-free LEDs.

                    I have the same headache and symptom pattern. I call it an eyegraine.

                    All LG OLED TV's have PWM. Some reveiw sites report that they would not have, but it is easily confirmed by a smartphone camera or DSLR. Set the shutter speed to 1/4000 and take a picture, you will see multiple black bands in the picture, revealing that PWM is used.

                    I had one of the LG OLED TV's at home for a couple of weeks, but due to the PWM, I had to return it. It did not cause severe eye strain, but still caused enough that I couldn't use it.

                    I replaced it with a Sony Android TV, which does not have PWM above 35 % brightness. I also need to disable Motionflow, as that causes similar flicker as PWM. (I did try the LG OLED without truemotion too, but it still caused eyestrain, as there is the PWM)

                    I think all OLED displays have the PWM, some at the lower frequency and amplitude, like the One Plus 3. The reason I think is that the pixels will start to burn in, if they are not flickered. Other reason of course is the dimming.

                      degen Rtings is pretty good at measuring stuff, you might want to check their site out. None of the Sony 2015 and 2016 models they tested except for 2 had PWM.

                      Maxx Motionflow doesn't cause PWM, it's the soap opera effect caused by synthetically interpolating frames. What you're probably picking up on is BFI, black frame insertion. This is something you can switch off by changing the "Clearness" slider.

                            I went to BestBuy to check out the Sony 2016 TVs. According to Rtings, the X850D is the highest end model that doesn't use PWM. The PQ was very average, mostly because the blacks were poor. That would undoubtedly improve with proper calibration, but probably not enough to my liking (I was a fan of plasma for black levels before my eye problems, as I like to watch at low brightness in a dark room, something plasma's absolutely excel at). There was a X700D next to the X850D and my mom pointed out the dithering on the X700D to me! I didn't even mention it to her! After inspecting both it was clear that there was heavy dithering on the X700D, but not on the X850D, which was very stable. The X700D uses an IPS panel and the X850D uses a VA panel. Perhaps that is the explanation? The programming was the same on both TVs.

                            The X930D, which Rtings says has a PWM frequency of 730 Hz, was miles better in PQ. It's what I would consider to be a good TV. I don't care about 4K or HDR so at this price point I would rather score myself a good plasma second-hand if it were for personal use (something I'm thinking about doing in case my TV fails). Anyway, at this point my eyes were hurting from the overhead lighting so I can't tell if that level of PWM was acceptable to me. Also the demo mode calibration is of course very bright on all the TVs and that will cause me problems regardless.

                              8 days later

                              MagnuM Could it be possible the source of your eye strain is not the TV but the device that is attached to the TV?

                                  @MagnuM Wow, we must be two alter-egos. I happen to have a Dell U2410 as well (it's a great monitor!), and I have almost the exact same setup as you do with f.lux and the brightness and contrast levels. I've used this monitor for many years now and have not experienced any problems.

                                  I have a Sony LCD-LED TV ( KDL-55W950B ) and while it's great for movie-watching, the "eyegraines" are a big problem when gaming. Just like you, these "max headaches" can last for days and can seriously hamper my productivity at work. I recently purchased a PS4 and this is very noticeable, while PC gaming has never been much of a problem on my old U2410, although I do still get fatigued faster than most people.

                                  I've since connected my PS4 directly to the U2410 and I'm playing the games there, which is much more comfortable. I think my gaming experience (with the fast movements) can be comparable to what you would experience when watching a hockey game.

                                  After doing some research, I thought the problem had everything to do with the PWM of my LCD-LED TV. So it's disappointing to hear that such "LED symptoms" happen with PWM-free OLED TVs as well, as I had been intending to purchase one of the new LG OLEDs by the end of 2017. If PWM isn't the problem, then what is?

                                  I also used a retina MBP at work for about a year. Despite it having a LED screen, I thought it was an amazing display and had absolutely no problems, so I don't know what's happening there. I can also have my face buried in my OnePlus One phone for an entire day and have very little problems. Perhaps it is because these displays have a high-frequency PWM unlike my Sony TV which probably has a low-frequency PWM — so perhaps my particular problem is related to PWM while your problem is related to some other characteristic of LED screens.

                                  Have you experienced the LED symptoms with smartphone LCD-LED screens as well, or with LED-backlit laptop screen like the rMBP?

                                    Monie Actually the all LG OLED TV's use heavy PWM. I wouldn't give up on OLED until we see some PWM-free sets.

                                        degen Where did you read that? I just looked up rting.com's review of the LG B6, and they didn't find PWM. Well, there is some kind of flicker, but it looks more like the smaller 60 Hz flicker from the OnePlus 3, or Samsung Galaxy Edge with the custom PWM-disabling kernel.
                                        http://i.rtings.com/images/reviews/b6/b6-backlight-large.jpg
                                        Sadly they didn't measure the flicker index. The spikes look a little greater than I'd expect.

                                            I can confirm that an LG OLED PWM caused eye strain to me. I had to return it.

                                              Maxx

                                              degen

                                              Oh, that's sad!

                                              Do we know if any of the new LG and Sony OLED TVs showcased at CES are without PWM?

                                                  can't remember anymore, the first cheaper full hd curved one. but I checked the new 4k models with a DSLR and they have the exact same pwm.

                                                    Maxx Thanks for the reply.

                                                    One question: Are you sure that the new 4K models that you saw were OLED models, or were they LED?

                                                    I'm asking because the difference could be critical. The Rtings reviews indicate that the OLED TVs don't come with PWM. However, the LED models probably do, which might have been what you saw.

                                                    • Maxx replied to this.
                                                        dev