Change graphics in-game (without needing to restart).

Hey I am new to scripting and I am not so sure if this is possible to do in Unity. Currently I have it for example;

 public void AntiAliasing(GameObject Description){
         sliderValue = (int)AASlider.GetComponent<Slider> ().value;
         switch(sliderValue){
         case 1:
             Description.GetComponent<Text> ().text = "None";
             break;
         case 2:
             Description.GetComponent<Text> ().text = "2x";
             break;
         case 3:
             Description.GetComponent<Text> ().text = "4x";
             break;
         case 4:
             Description.GetComponent<Text> ().text = "8x";
             break;
         }
     }

This being where I am able to set the AA in the scene dependent on the UI slider value for it. However when I run this script the screen goes black and nothing else appears. I am also running this with an Oculus Rift and was wondering if anyone knew how to get the image back after changing the graphics settings.