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Re: Display hurtful on LCD screen with Wheezy



First, thanks all of you to try to solve the issue I encounter with Debian.

I will come back now to some of the points you mentioned in the discussion.

 How important is it to you to be able to run Debian? Would it be
 worth some spectacles, or some new ones if you already wear them?
 (This solution worked for me.)

 Have you tried any of the rpm distros?

I can live with other distributions than Debian, but I would like to use it as a base to setup a very lightweight working environment. I found that the Ubuntu distribution contain a lot of extra-tools that I would not need, and their use in cpu resources is slightly higher than pure Debian (on the same hardware). No spectacles for me. I don't think I need some, because everything is very fine whenever I am running Ubuntu-based distributions and I am able to work for hours in front of the screen without feeling any disturbance.

I haven't checked what is the outcome with rpm distros, but plan to have a look soon on Fedora to check how it goes.

 Incidentally, do you know what changed immediately before this
 started to happen?

Nothing has really changed. This phenomenon appeared as soon as I started to boot into fresh Debian installation.

 A minimum refresh rate of 72Hz is recommended (same as average human
 heart rate) to minimize optical discomfort that you seem to be
 suffering. Less than that the screen will often jump about and make
 it difficult to see properly. See if you can do something about that.

I am running Ubuntu-based distro at 60Hz (on the same hardware) without experiencing this problem.

 Try adjusting the brightness and contrast (of the display itself).

Lowering the brightness helps a little bit to make the pain more bearable, but it is still unpleasant and hurtful after a while.

 Do the fonts look different in Debian? If so, in which way? If
 they do, you could try to find out how they are rendered and try to
 have them rendered the same in Debian.

The fonts (with the same hinting and antialiasing settings) look very slightly blurrier on Debian than on Ubuntu. I heard about the libcairo package difference between Ubuntu and Debian, but I am not sure this is still relevant. I guess some improvements have been pulled to the Debian libcairo package to make the fonts look almost as nice as they are in Ubuntu.

 You can try the following in ~/.fonts.conf.d --- I wasn't happy with
 how the fonts were rendered and I like them better with these
 settings:

I tried to use any kind of settings (playing with the "Appearance" menu of the desktop environment, adjusting the different parameters through fontconfig-config and add these paramaters in /etc/fonts/local.conf) with visible results (the shape of the font is changing) but no effect on the discomfort I experience.

 [2]: http://www.infinality.net/blog/infinality-freetype-patches/

I haven't check that and will give it a try.

 Try to identify what's causing your discomfort: Does your monitor
 flicker when you're running Debian? Fonts too small/blurry? Bad color
 scheme? Something else?

Well, actually, I don't think the fonts might be the main reason. Because the phenomenon seems to be very subjective, I tried to explore this idea because I knew some major differences in how Debian and Ubuntu deal with fonts existed. But the unpleasant feeling is present (even if not so intense), just by looking at the background of an empty desktop. It seems that the light is too intense, too violent (even when I reduce the brightness) and that my eyes keep on adjusting the focus with no interruption in an almost imperceptible manner.

 Consider removing proprietary drivers as an experiment.

Sure I have to try that.

 Yes, but better if you describe in detail what kind of pain you are
 feeling because how the screen has to look like can be sometimes a
 matter of personal preference

I tried to do so couple of lines above. Important point, I used to work with Debian as my main OS some time ago (on Sarge, as far as I remember) on another laptop with LCD screen, and never experienced this. I mean, if I agree that we can't exclude the personal preference issue, I am not physically allergic to the Debian environment ;)

 Mmmm... At a first glance I see nothing wrong from the xrandr output,
 I mean, technically speaking both resolution and refresh rate values
 are right.

Yes. Me neither. The only parameter I couldn't check (due to my lack of knowledge) is the horizontal refresh rate. Any idea how I can get this value ?

/lionel





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