Just purchased an Iiyama XB2380HS, a 23" IPS/LED monitor. It's hooked up to a GTX660. After prolonged (1-2) hours continuous use, mostly text and editing (i.e. white background) I also experience unacceptable eye strain. There is also a whitish haze (most likely IPS glow) coming off the screen when viewing at ~50 cm under a horizontal angle of ~20 degrees, basically working position.
My other display is a NEC P221W PVA display which does not have this at all. It could be due to the higher refresh rate, the Iiyama is rated 60Hz, the NEC 85Hz and it's also not an LED display. Though what I also notice on the IPS display is that dark backgrounds give an unacceptable glow under only slight viewing angles. The glow decreases when sitting straight in front at ~1m distance. Thus, the advertized enhanced viewing angles using IPS technology are more likely a marketing gimmick when buying a new display.
Interestingly, following jerrolds advice of increasing brightness to 100%, this indeed removes the flickering when moving an object in front of the screen (because PWM is disabled at 100% brightness?). I am going to see how this is going after long term use, though I already arranged for an RMA and am going to try new LED displays with VA technology. Reportedly, these newer displays are suffering from the same glow effects though.
Edited by Hugo2013 - 7/3/13 at 8:53am