Sudden reduction in render/draw distance!!

As the title suggests, the render/draw distance has drastically reduced to the point the immersion on the planets has gone. I had been changing settings in both the game and through the nvidia control panel to settle my FPS as it was a little volatile (bouncing between 30 and 50). Despite returning all setting back to default nothing has changed. Anyone able to offer suggestions to where I've gone wrong and what might have happened?