Motion Blur, Edge AA, Texture Anisotropy, and Post MSAA.
I'm able to play the MP because of this, it was too blurry and hurt my eyes too much before.
Here are the console commands

They all need to be entered once in a server.
r_UseEdgeAA=0
r_TexMaxAnisotropy=0
r_motionblur=0
r_PostMSAA=0
try this one too>>
g_useHitSoundFeedback=1
Console command (at least here in the uk) is `(key left of the number one)