The mammalian visual system evolved as a detector of information in the three-dimensional world. Data are presented which indicate that, with a two-dimensional presentation such as a printed page or screen, the optic tracts which normally carry Z-axis information serve merely as visual noise. Optical means were employed to delete the information from these tracts, and improved operator performance resulted. With or without this deletion, certain observer categories showed greatly superior performance, such that these observers should be utilized for particularly critical monitoring tasks. A simple test battery was developed having predictive value for selection of these observers.