Ok, so it's been happening for a bit time, it's not a huge problem but it's getting on my nervs.
Thing is, when working on some darker (blak, silver) backrounds, i can see monitors refresh rate. (like when you record with camera PC screen and you see lines (usually old CRT), and refresh rate, its not that big but its disturbing). When you do something on lighter backgrounds it's almost not seeable.
Monitor is Philipps 220E, but it's not monitors fault because i tried new monitor and same happening again.
I tried changing both power and vga cable, no help. Didn't tried changing adapter that changes DVI-S to VGA for monitor. (looking for new adapter)
GPU is AMD Radeon 7850.
Any ideas?