@MagicAndre1981:Are you sure it isn't your avatar that's causing the headache
no, I can open 2 programs (1 GDI and 1 with Direct2D or WPF) and if I look at the Direct2D/WPF rendering I get the headache. Switching to the GDI Windows stops it. If I switch back to the WPF/Direct2D Windows the headache is back. Before the font update I also had burning eyes after a few seconds watching at a WPF/Direct2D Window. For example I can see in VS2010 which parts are WPF and which are GDI. Everytime my eyes burn I know that I see a Window which is coded with WPF.