Recent studies have attempted to link environmental cues, such as lighting, with human performance and health, and initial findings seem to indicate a positive correlation between the two. The technical question this paper addresses is the use of Daylight Autonomy (DA) to simulate the probabilistic and temporal potential of daylight for human health needs. It will isolate one topic: human circadian rhythm organization as a proxy for human health. We use outcomes of photobiology research to define threshold values for lighting, which will be used as goals in simulations. These goals will consist of spectrum, intensity, and timing of light at the human eye. The variability of key architectural decisions in hospital room design- orientation, window size, and glazing material—are studied for their impact on achieving the goals. We chose healthcare settings as our case study, with the intent to validate and pursue this research in the future using patient outcomes and data collected in hospitals.