That was a good read!
+1 El Reg
Have some Greg Egan in return (Permutation City, 1994):
Paul uncovered his eyes, and looked around the room. Away from a few dazzling patches of direct sunshine, everything glowed softly in the diffuse light: the matte white brick walls, the imitation (imitation) mahogany furniture; even the posters -- Bosch, Dali, Ernst, and Giger -- looked harmless, domesticated. Wherever he turned his gaze (if nowhere else), the simulation was utterly convincing; the spotlight of his attention made it so. Hypothetical light rays were being traced backward from individual rod and cone cells on his simulated retinas, and projected out into the virtual environment to determine exactly what needed to be computed: a lot of detail near the center of his vision, much less toward the periphery. Objects out of sight didn't 'vanish' entirely, if they influenced the ambient light, but Paul knew that the calculations would rarely be pursued beyond the crudest first-order approximations: Bosch's Garden of Earthly Delights reduced to an average reflectance value, a single gray rectangle -- because once his back was turned, any more detail would have been wasted. Everything in the room was as finely resolved, at any given moment, as it needed to be to fool him -- no more, no less. He had been aware of the technique for decades. It was something else to experience it. He resisted the urge to wheel around suddenly, in a futile attempt to catch the process out -- but for a moment it was almost unbearable, just knowing what was happening at the edge of his vision. The fact that his view of the room remained flawless only made it worse, an irrefutable paranoid fixation: No matter how fast you turn your head, you'll never even catch a glimpse of what's going on all around you ...