blow45, me thinks that both of us posted with good intentions but that our points might be easily misconstrued. For my part, I made a mistake by implying that eyestrain attributed to using an iMac is due solely to the LED backlighting. I should have written that eyestrain may be due to the LED backlighting or the high reflective display, or both. (I also suspect that high-resolution displays are problematic for some people, but it doesn't seem to be as much of a problem.)
Sensitivity to LED backlighting and reflective displays is very subjective and it appears that sufferers are in the minority. But there is no way of knowing how prevalent it is because nobody is keeping track. I also think that there may be some people who are affected and who don't consider their computers as contributing to their symptoms. I have read more than a few posts where people spent time and money on doctors because they just assumed that
they had a problem, not their computer display. Others just learn to live with it.
From my experience and what I have read, the LED backlight problem varies in severity depending on the Mac in question. The date of manufacture also matters, since online eyestrain-related complaints about portable Mac displays began showing up after the introduction of the first unibody MacBook Pro in late 2008.
I owned an early 2008 15" MBP with a matte display for over three years. It was my first LED display and it never caused me a lick of eyestrain. In fact, I purchased it mainly for its display after Apple discontinued offering matte displays in the MBP line.
The early 2011 13" MBP that replaced it caused me problems at first but it wasn't as bad as the MBA. Whether that is because the MBA is also high-res I cannot say but the MBA and MBP do utilize different LCDs. I was able to mitigate much of the problem by applying calibration settings suggested in that Apple forum link, reducing the brightness using the program Shades and limiting the amount of time that I spend staring at the display, especially when it is showing something bright like a white Web page.
I attribute the problem to the LED backlighting because of how the symptoms manifested and my response to the display even before I spent any time actually doing any detail work. Enlarging fonts didn't improve things. It isn't just the brightness of the display that is bothersome; it's the quality of the light itself.
I've worked on a number of glassy LED iMacs, sometimes using the display 3-4 hours without a break. I haven't experienced any appreciable eyestrain but in every case the iMacs were situated in rooms where there was no overhead lighting or windows causing reflections. I wore dark clothing so my reflection was greatly diminished.
I prefer a matte display because reflections are not a problem and I prefer the rendering of images. I do image editing and glassy displays are too saturated and lacking of nuance for my taste.
I won't be replacing my 2006 24" iMac with another even if Apple brings back a decent anti-glare display. Why? Because iMacs lack basic ergonomic adjustments. The only adjustment is a few degrees of tilt... That's helpful when dealing with annoying reflections of overhead lighting, but it isn't enough. At the very least it should be possible to easily adjust the height of an iMac. The G4 iMac may have looked funny, but it was an ergonomic masterpiece.
Since December I have been using an NEC 2490WUXi2 display connected to a 13" MBP. The colors are gorgeous, it is very accurate with basic calibration and the height can be adjusted with one hand. And yet its stand is more sturdy than an iMac. It also has a warranty that is a year longer than extended Applecare and you don't have to pay extra for it.
Apple has some catching-up to do, but I won't be holding my breath...
