Light related problems in the video display terminal (VDT) work environment are discussed. A number of field investigations have indicated that glare is a common problem in offices where VDTs are used on a regular basis. For example, in a study of 905 VDT users at New York State office facilities, NIOSH found that 31 percent of the subjects rated lighting conditions as producing much glare and 42 percent were bothered by screen glare. Sources of glare problems are discussed. These include direct glare from unshielded windows and overhead lighting fixtures and specular or diffuse reflections from VDT screens. Glare sensitivity and VDT user characteristics are summarized. The authors state that properly designed lighting systems are the most desirable means for controlling glare. Indirect lighting can eliminate sources of concentrated glare; however, wide reflections off walls and ceilings can result in stray light reaching the VDT, causing diffuse reflections from the screen. Using blinds or drapes over windows and filters in front of VDT screens can also reduce lighting problems.