Glitchy Gameplay Graphics

Hello, 

For the last year or so, while playing different games, I have experienced problems with graphics. It seems to be the there are constantly flashing patches or black squares appearing on the screen and this has been shown to happen in 3 different games (Witcher 3, Ratchet and Clank, FFXV) and I am wondering what is wrong with my PS4 and is it fixable? I have attached a picture which shows an example of the black squares/regions I mentioned. If someone could help me, I would be incredibly grateful.