According to the below article,flickering between 80 to 2000 Hz causes Stroboscopic effect while up to 2500 Hz we are able to detect Phantom Array effect (ghost effect).
source: https://alamembers.com/Portals/1/9_0%20Naomi%20Miller-Flicker.pdf
Another study found that stroboscopic flicker can still be detectable up to 3000 hz. Another term for stroboscopic flicker is invisible flicker. (in another thread I saw on ledstrain, I believe when manufacturers claimed that their display is flicker free it is referring that their flicker is above 2500 or 3000 hz. It is not exactly flicker free. TUV rheinland certified flicker-free are also implying this too.
source: https://www.alexfergus.com/blog/light-flicker-health
Lastly, according to another study I read, for individuals sensitive to flickering, they are affected even at 11000 hz.
Not including sensitive individuals, it is clear that none of the oled phone is safe for long hours of use. I really wish to buy into the advertised "high flickering eye protection" phones like Honor Magic 5 Pro, P60 Pro, or Oppo Find X6. However, their flickering hertz are simply just way too low. I wish manufacturers will finally move on to using Mini-Led displays as mainstream.
Sometimes in challenging lighting conditions, I just want to use a smartphone to snap a really good picture and toss it back to my backpocket. The current camera flagship phones are really attractive, capable of capturing really far subject with minimal loss in quality. But the problem is that they all come with oled screen and that I can't even look at it for a split second without my migraine triggering.
I don't mind even with getting a PWM phone with above 30,000 hz pwm (I did tried 21,000hz and it still gave me mild headache) as a good travel pocket camera. It seems as of now — to my knowledge, appears to be difficult.