At present, most lighting installations are designed simply to give specified average illuminance on a horizontal working plane, although sometimes predictions are made of the level of discomfort glare to check that it is within recommended limits. In many cases no other design work is done. To ensure good visual task conditions in the office it is important that other aspects of the lighting are considered. By doing so, a more efficient working environment will result with less likelihood of problems of visual distraction or fatigue and the porential for more efficient energy use. Office lighting is designed primarily to enable visual tasks to be performed by the occupants; it should, therefore, be designed to make the task as visible as possible. Bright reflections in the task will reduce its visibility and may cause discomfort. This digest considers the causes of these reflections for common office tasks such as written and printed material on paper and visual display units associated with word processors and other computer operations. The use of Contrast Rendering Factor (CRF) to quantify the effect of reflections is explained and guidance is given on acceptable levels of CRF and methods of calculation and measurement. Suggestions on design to avoid veiling reflections in offices are made.