This is not a fix, put just a tweak.
IV. TWEAKS 1. For NVIDIA user: Go to the NVIDIA Control Panel, then with the "Manage 3D settings" tab selected on the left side of the window, select "Program Settings", find "The Witcher 3 (witcher3.exe)" and change the following variables: + Anisotropic Filtering: On + FXAA: On + Texture Filtering - Quality: High Quality