My HTC One M8 was the best phone I used since the Galaxy S2, and was 1000x better than my Xperia ZL (which I suspect used PWM). It still wasn't good enough to use for more than 30+ seconds though. I bought an iPhone 6S and although it causes eyestrain and headaches more quickly, I can get far more done in less time. Since I am not doing any colour-sensitive work and don't care at all about how it looks, I inverted the colours. Otherwise I find the iOS7+ theme far too harsh on the eyes, which amplifies whatever hardware or driver problem there is.

Using these settings to reduce eyestrain:
Min brightness
Zoomed
Inverted colours (must change wallpaper to pure white so it becomes black)
Night Shift (scheduled to always on) (doesn't work while colours are inverted)
Grayscale (at night)
Reduce motion
Reduce transparency
Reduce white point
Increase font size
Bold text
Using voice commands as much as possible

Of course none of these reduces the underlying problem. they just delay the onset and allow me to get in and out before a problem starts.

Still the screen seems offensive. I think it is the lensing effect (to increase readability in the daylight) as described on the Apple support thread.

5 days later

Hi, about LG G2 - it's first phone which I can use since my iPhone 4 but only with bluelight filter from play store turned on 25-30% without this screen is blueish and got pain after few minutes. So I hope using other LG like 4, 5 or V10 with this filter should be ok for me. When trying those in store it seems to be ok.
I have iPhone 6 and it's usable only for 1 minute with min. brightness I feel eye pain after using this. Had Macbook Retina 2015 and I gave it to my wife and using now her old Air with min brightness for few hours it's usable.

Ok, so a quick update.

My HTC One M8 (my primary device at this time) has the following screen:

m8_lg_novatek_panel
PANEL_ID_M8_LG_NT35695

Since upgrading the firmware to the Marshmallow-ready firmware, it bothers my eyes more than before. Everything is a little harder to look at. I will be downgrading to the Lollipop firmware shortly, looks like something specific to Marshmallow is making the display drivers unusable for me.

I've personally narrowed my problem to a combination of Blue light and FRC/Temporal dithering. PWM doesn't seem to bother me very much at all. I've discovered that some devices I have used for years without issue have DRASTIC levels of PWM. So that really isn't the issue.

    Amendment to my earlier post: I can only use my iPhone 6s for a few seconds now. The dithering is very obvious, but I don't know if that's why it hurts. A very costly mistake for me.

      degen Hmm, and yet I don't seem to have any problems with my iPhone 6S+ It seems even better than my previous iPhone 5 (probably because the screen is larger, making text easier to read on it)

      • Gurm replied to this.

          MagnuM I think we determined in a different thread that temporal dither isn't your issue, so the iPhone is likely to be very usable for your tired eyes! (I wish it were so for me...)

            3 months later

            I'm typing this on a OnePlus 3. Been using it for 3 hours straight. It's an "Optic AMOLED" screen with dual polarizers. It uses PWM at least at lower brightness which I confirmed with my iPad camera. Actually I'm in the PWM zone almost the whole time. A little eye strain, probably because I didn't use auto brightness at first. I wanted to stay out of the PWM range which notebookcheck already tested to be at 0-10 %. But it is definitely larger than that. Knowing that the OnePlux X was said to be at 25 %, I selected around 30-40 %, which was probably too bright indoors. Now I'm using a manually adjusted auto brightness. It feels much better than those devices which I had to turn off after just a few minutes (even seconds). The next few days will tell if this device is a keeper. I will report back.

            • JTL replied to this.

              KM Oh.

              Their oscilloscope tests are accurate, percentages may be off and/or firmware differences.

                JTL I'm having doubts that notebookcheck is reliable. Or maybe xiaomi has different versions of the same phone.

                Using their recommendation for no pwm i bought a xiaomi redmi 3, and it gives me terrible headache. Since you cannot return phones here, i'm trying to see if i can use it at 100% brightness + f.lux like mode.

                BTW, you talked before about LG Nexus 5. have you tested it yourself in prolonged use ? did it cause any trouble ?

                • JTL replied to this.

                    Reporting back about the OnePlus 3. I think in theory it would be usable if it didn't have PWM and dithering. I believe PWM kicks in at 25% (tested with iPad camera, which shows running lines). Above that, the screen still flickers in a way. But it seems to be not a total "lights off". It's more like "higher brightness, lower brightness, ..." I can't analyse this because I don't have a better camera.

                    So having 26% as minimum brightness seems and feels like the best option to avoid the strong PWM. Going below that is difficult.
                    I tried apps that reduce brightness by software, but that introduces another type of flicker all over the screen, maybe temporal dithering. Captured with my iPad camera in video mode. And then I realized that even at 100% brightness, large areas of dark color always flicker rapidly even without using any filter apps.
                    The other option are "pixel off" apps. They make pixels black in various patterns. And this causes heavy color banding. The screen looks like 16 bit or less now. My explanations for this are either Android doesn't use 24 bit colors or the AMOLED screen's pentile matrix is applying temporal dithering to create more colors. Or maybe it's just normal for pentiles, since they rely on sharing pixels.

                    Any way, the eye strain is still too strong inside rooms, because 26% is relatively bright. To go lower I can choose between using auto brightness and have PWM, use color filters and create strong flicker, or hide pixels and realize this works but won't be dark enough in all environments. My best setting was using the apps Lux and Pixel Filter to have a minimum brightness of 26% and an automatic dark pixel pattern for low environment brightness. But it's still too bright if I want to use the device for multiple hours a day.

                    So I guess I have to go back to my old iPhone 4.

                    Gurm Hi Gurm, my device is S-Off, so I've been banging around different firmwares and OS versions between kitkat and marshmallow. I do see differences. I'm curious to know what firmware version # strings you have (attach a picture I guess) in your bootloader for the one that you say is fine in Lollipop.

                    To get to the bootloader, when powering on, you hold down the power and down-volume button. Likewise to force a reboot hold down the power and volume-up button.

                      All current generation OLED panels use PWM. This is by design to force better colour accuracy. Usually the frequency is about 240 as is the case in the OnePlus3 which is using a Samsung panel. A little bit is not bad, more factors are at play.

                      Saw a 6S+ in the store briefly that seemed nicer than the SE which is using an older panel.

                      Anyway the nice thing about this is, despite the annoyance today, due to the fast rate of refreshes, there's always something new coming down the pike to look at.

                      • KM likes this.

                      JTL No. I'll ask my brother for his camera tomorrow. I'm not a camera guy - how should i set it to detect pwm ?

                      Just set the shutter speed as low as possible and in non-automatic mode ? and take the picture with no flickering light around ?

                      • JTL replied to this.

                          autobot Highest shutter speed possible. I use 1/4000 shutter speed with my DSLR and a dark room (if possible)

                          What camera does he have out of curiosity?

                              JTL did use the htc-m8 with shutter speed of 1/8000 on the xiaomi redmi 3 , it seems no pwm(not running lines), but the pixels themselves do look noisy(but it's the same with the nexus 5 which also doesn't have pwm) , so i guess there's something else.

                              What could it be ? how should i attack it ? The display is ips lcd.

                                laclean i've had eye success with my alienware alpha (NVidia 7xx) + Dell ultrasharp U2414H with some overclocking. Also with my 2015 macbook air as a source.

                                i made the mistake of picking up a cheap iphone 4s though & now i'm back in sunspot zombieland. excited to try out the htc one..

                                • JTL replied to this.
                                    dev