That happens to me all the time , usually its because my draw distance is set to high or my WIFI is acting up or some mix of the two. Firestorm Just recently released a new viewer , if you chose to update it I would suggest you check the settings to make sure everything is set properly .
if none of that helps you can always remove your make up layers and then reapply them ..I put on a lipstick layer once that caused my whole face to go blurry.