A committee assembled by the National Research Council recently completed a review of the state of knowledge about the effects of lighting levels and quality on student performance . Given the dearth of research specific to students, the committee also considered related research pertaining to adults. The committee concluded that indoor visual conditions are normally adequate for most children and adults, given that people "have very flexible visual systems". The committee suggested that lighting conditions may be inadequate for those without properly corrected eyesight. This expression of concern appeared to be largely based on theoretical grounds, as no direct evidence was presented on performance decrements. The committee also indicated that there may be effects of indoor lighting on performance via the effects of lighting on the circadian system which influences depression (e.g., seasonal affective disorder) and sleep, but again, direct evidence of performance decrements associated with indoor lighting was not provided. Based on this review, at the present time we cannot conclude that improvements in lighting levels or quality significantly increases work performance.