by Pat Barker
The most horrific conception of a panopticon ever gives this book it's title. Truly creepy to the degree only, I hope, an Edwardian prison can be.
Aside from that, The Eye in the Door is book 2 of the Pat Barker's Regeneration trilogy. Unfortunately I read them out of order so I'm always somewhat confused as to which elements were in which book. But I know they were all good -- for a full review see Regeneration in this list, or The Ghost Roadin Booker Me.