What really is this? i'm studying The Plough and the stars, The Great Gatsby & The King's Speech
General vision and viewpoint is pretty much how the characters see the world (their viewpoint) and also how the author sees the characters (the vision). For plays as well it can be how the audience are suppose to see the characters. For example the characters see the world in the plough and the stars as quite bleak but with some hope. The author sees the Covey as himself and the audience see Fluther as comic relief.
Hope this helps and may the odds be ever in your favour