You may have seen the news about a study conducted by Cornell Professor Rana Zadeh. The study compared nurses working in two wards of an acute-care unit. While the working conditions were similar in terms of organization, environment and the type of patients they cared for, the significant difference was the availability of windows in the nurses' work stations. The results showed that nurses with more natural light had lower blood pressure, talked and laughed more and had better overall moods than their counterparts in the ward with fewer windows and less natural light. In the study they provided evidence that working in natural light improves performance, mood and alertness, and has a positive effect on people both physiologically and psychologically.