It all started with the fact that I had ordered me quite naive and ignorant to Samsung S24B420BW. Of course, I found the large 16:10 class, but somehow I got to work an hour or two a headache and my eyes began to tear.
Since I started googling, came among others in the forum at Prad.de a related thread, and first learned something of PWM fibrillation. (So I was not prepared for auto-suggestion eye problems, but they came to me out of the blue.)
Well, as I was reading in the Prad test, the HP ZR2440w has such a high PWM frequency that the flicker should not bother, I ordered this. Optimistic that my problems are over now, I took it into operation. But: Not a bit better than the Samsung. Headache, watery eyes. That the slightly higher frequency improves the thing was - at least for me - definitely not the case.
Because I had almost no desire. But then I ordered but my Eizo EV2436WFS-BK. After commissioning skeptical first time amazed at how well the colors are. (No red, green, or blue, but perfect in my eyes. The other two monitors I had to adjust a lot, until I had a nearly as good picture.) Leave contrast to the preset 50, brightness at 20 down, All Eco-dimming functions disabled. Lo and behold, I suddenly can work for hours and my eyes feel burdened in any way. Madness! So it was actually the PWM flicker!
By the way: In the first two monitors no flicker was also seen by view by mobile phone camera. (This is often recommended as a test.) And yet, they definitely have flickered! The problems were limited when I'm rumgezappt the Internet or photos have been viewed. I have, however, (eg in Word) focuses text read, that went immediately on the eyes. Even that might perhaps explain that not everyone and immediately affected by the PWM fibrillation.
But I can only say: people, let yourselves a no flicker of monitors! At some point - at an earlier, the other later - the eye problems are set! Since I am after my painful experiences now safe!