This project is part of the research program "Creating Healthy Environments Hospitals" (CHEH), which aims at identifying environmental conditions, related to light, which improve the staff retention and effectiveness. One of the identified issues addressing patient safety are misread medication labels by the staff due to an inappropriate lighting condition. The first step in this project is to determine what lighting condition, under which conditions, is appropriate for visual performance related to patient safety, through user tests and data collection in hospitals.