dark color

https://postimg.cc/dZFHj617 https://postimg.cc/wtyRwdyP Can someone tell me what are these black spots on my screen? it can only be seen on dark colours like gray and blue(on white it cant be seen at all) Screen is Lcd Lenovo ThinkVision 76hz 1280x1024 (idk which model). I dont know when it...