The Impact of Light on Outcomes in Healthcare Settings

Light is critical to human functioning in that it allows us to see things and perform activities. But it is also important because it affects human beings psychologically and physiologically. Several studies have documented the importance of light in reducing depression, decreasing fatigue, improving alertness, modulating circadian rhythms, and treating conditions such as hyperbilirubinemia among infants (Ulrich, Zimring, Joseph, Quan, & Choudhary, 2004). Further, the presence of windows in the workplace and access to daylight have been linked with increased satisfaction with the work environment (Boyce, Hunter, & Howlett, 2003; Edwards & Torcellini, 2002). Studies also show that adequate light levels are linked to reduced medication-dispensing errors in pharmacies. Thus, incorporating light into healthcare settings can be beneficial for patients as well as the staff who work there. This paper considers the mechanisms by which light impacts human health and performance and reviews the literature linking light (daylight and artificial light) with health outcomes in health- care settings. Studies conducted in other settings that are relevant to the discussion also are exam- ined. Several studies have addressed the technical, architectural, and energy aspects of providing optimal lighting conditions in different areas of a healthcare facility and are not reviewed here.