<html><head></head><body><div class="ydp9255c4beyahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false"><span> <span>I've been using Ubuntu 14.4.0 (with updates) for many years and can't switch to any newer Linux distribution.</span><br></span></div><div dir="ltr" data-setdir="false"><span>Actually on attempt to upgrade to anything newer I got problems with eyes and head (actually problem feelings are started in muscle at my right head side and then in eyes - irritation, burn, discomfort and so on, then i got a weakness in my full body). <br></span></div><div dir="ltr" data-setdir="false"><span>My hardware configuration is same during attempt of upgrade and I have similar filing <span><span class="ydp813558b8tlid-translation ydp813558b8translation" lang="en"><span title="">regardless</span></span></span> of used driver (opensource or proprietary).</span></div><div dir="ltr" data-setdir="false"><span>Problem feelings doesn't depends on used graphic card: AMD/ATI, Nvidia or Intel.<br></span></div><div dir="ltr" data-setdir="false"><span>The hardness of feelings just depends on distribution: the hardest ones on Ubuntu 19.04 and less ones on Mint 19.1<br></span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><span>I think that some relevant for my story changes was added to graphic stack around 2014 year <br></span></div><div dir="ltr" data-setdir="false"><span>or maybe even before 2014 and default <span>behaviour</span> was switched to them around 2014.<br></span></div><div dir="ltr" data-setdir="false"><span>There are several report of same problem with intel graphic made in 2014:</span></div><div dir="ltr" data-setdir="false"><div><span><a href="https://lists.freedesktop.org/archives/intel-gfx/2014-January/038104.html" rel="nofollow" target="_blank">https://lists.freedesktop.org/archives/intel-gfx/2014-January/038104.html</a><br></span></div><div dir="ltr" data-setdir="false"><div><a href="https://lists.freedesktop.org/archives/intel-gfx/2014-March/042689.html" rel="nofollow" target="_blank">https://lists.freedesktop.org/archives/intel-gfx/2014-March/042689.html</a></div><div><br></div><div dir="ltr" data-setdir="false">Actually I can't use any display with LED backlight and still using one with CCFL. Maybe this changes are related to LED display support.<br></div><div><br></div><div dir="ltr" data-setdir="false">There is also report on ledstrain site:</div><div dir="ltr" data-setdir="false"><a href="https://ledstrain.org/d/384-linux-users-any-known-good-distro-de/15" rel="nofollow" target="_blank">https://ledstrain.org/d/384-linux-users-any-known-good-distro-de/15</a></div><div><br></div><div><br></div><div dir="ltr" data-setdir="false">Could you suggest which changes could be related to described problem?</div><div dir="ltr" data-setdir="false">Could it be some hidden dithering in graphics stack or something else?</div><div dir="ltr" data-setdir="false">My attempt to play with different configuration options doesn't give me any result (including dithering disabling in graphic card driver)?</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Best regards,</div><div dir="ltr" data-setdir="false"> Mike<br></div><div><br></div><div><br></div><span></span></div><div><br></div><div><br></div><div><br></div></div><div dir="ltr" data-setdir="false"><span></span></div></div></body></html>