Teddy Daniels: Baby, I love this because you gave it to me, but it is one fuckin' ugly tie.
Warden: If I were to sink my teeth into your eye, right now, could you stop me before I blinded you?
Teddy Daniels: Give it a try.
Warden: That's the spirit.
Dr. John Cawley: You blew up my car. I loved that car.
Dr. John Cawley: We don't know how she got out of her room. It's as if she evaporated, straight through the walls.
George Noyce: Don't you get it? You're a rat in a maze.
Answer: The bandage is a symbol indicating when and when not Teddy is caught in his delusions. When the bandage is on he is delusional, thinking he is the marshal finding out all the dark secrets of the facility. When the bandage is absent he is lucid and aware of his past crimes and his own delusions.
Wrong. It's on the whole movie until he takes a shower. The bandaid is off but yet that's the scene where he runs in the lighthouse thinking he's the Marshall still. Did you watch the movie at all?