Frankly, I find it unusual for all content to appear this way. Please give more details on precisely what sources/shows/providers you are watching.
OTOH, some types of content will generally lead to flicker. Certain Comcast shows and sports, for example. Here is some useful reading on refresh rates on modern HDTVs:
Is there a fix for the flickering on any Samsung tv's or should I never buy another Samsung product? The TV is only 2 years old. The model is UN65HU8550.