Visual Performance Under Conditions of Transient Adaptation

It has long been known by lighting engineers that a shift in eye movement from a dark to light surface and back again has a strong (and deleterious) effect upon visual acuity. Engineers faced with the task of designing efficient offices, adequate school buildings, and safe and productive industrial plants have traditionally paid a good deal of attention to brightness ratios between task and surrounding environment. The study described here is a step toward the more exact determination of what these ratios should be.