Situation: I am sitting on a chair facing the table with a whiteboard on my left within reach.
Alternative situations: I am sitting on a chair and doing homework on the desk in front of me while my head is leaning on the wall to the left side. I am sitting on a chair and desk in the bottom left corner of the room taking notes on a piece of paper.
Question: Where should I look if I want to see who is knocking on the door?