[snipenekkid]

Some have spectulated that eye strain is not soley limited to the current convention wisdom of the mere presence of the backlights in LCD panels. A few folks are now pondering is if this eye strain is a function of DPI and/or PPI. And that the backlight only making the lower pixel density screens more obvious to some people thanks to the increased "dot pitch" (essentially the space between the pixels on the screen.)

Here are some interesting pages detailing the various screen charistics.

• Pixel densities for different devices: http://en.wikipedia.org/wiki/List_of..._pixel_density
• How these numbers are calculated: http://en.wikipedia.org/wiki/Pixel_density
• Dot Pitch (still relevant but not as oncce upon a time with CRT's: http://en.wikipedia.org/wiki/Dot_pitch
  {Dot pitch vs. pixel pitch gets twitchy as there is a difference between dot pitch and pixel pitch but, there is only so much room and time to comment}
• Definitions of the various screen resolutions and related jargon: http://en.wikipedia.org/wiki/Display_resolution

Interestingly the iPad has roughly the same pixel per inch (PPI) values as my 17" laptop. I have no problem with either display. The iPad screen is about 8%-9% higher than my laptop LCD display. Difference is it has a matte finish panel vs. the über glossy panels on iPads. The matte finish seems to diffuse reflections far better than the reflections visible on super glossy screens like that of the iPad. But in defense of the iPad once there is a nice bight image on the screen the reflections pretty much are a non-factor save for bright overhead or lights behind the user.

Oh, something we all seem to misuse is the word glare when referring to various screens. Yeah, we all do it as what we are seeing is likely better termed a refelection. Glare is a different beast all together.

JSWolf mentions this here in an old 2009 post:

Originally Posted by JSWolf

Please do not incorrectly use the term glare to mean reflection. The 600 does not have a glare issue. In fact, the the touch layer diffuses glare more so then a plain Vizplex screen.

What you are doing is using the term glare to mean reflection. And this will cause people who have not seen a 600 to think it has a glare problem when this is in fact, not true.

That is a good point as glare can be a type of reflection so in a way it's fine to use the terms interchangeably but in reality they are different animals as a reflection is not dependent on the intensity of the light emitting from the offending light source or object. Glare refers to an intensely bright light source. But as we all know what's being discussed I doubt it matters. Still I sense it can't hurt to at least be aware there is a difference.