Describe symbolism in The Eye in the Door by Pat Barker

In Chapter One, the narrative explains its own title. The eye in the door represents different things to different characters. To Beattie Roper, the eye symbolizes the scrutiny under which she continues to live. As a pacifist, Beattie Roper is, by this time, accustomed to being watched by the government. To Billy Prior, the eye represents the self looking inward. That is to say, Billy sees the eye as a part of himself which observes and insinuates itself into his mind as a separate entity. The "eye" that watches Billy Prior is his own subconscious.