Humans spend 90% of our lives indoors. We are shaped by these spaces, often more than we realize. Lighting design, in particular, is critical to physical and mental health. The human body responds to light in nonvisual ways: specific wavelengths and intensities of light trigger biophysical reactions that impact both mental and physical wellbeing associated with the cardiovascular, digestive, endocrine, immune, muscular, and nervous systems. Unfortunately, the majority of interior environments fail to provide humans with the type and intensity of lighting that is most beneficial. This not only deters optimal performance, but also causes serious health problems. On the other hand, proper design can advantageously use light as a therapeutic and a neurophysiological stimulant. Moreover, many of these lighting strategies, which will be detailed in this paper, are feasible for common developers. Lighting designing that benefits human health often offers the added financial benefits of reducing energy consumption, increasing productivity, and reducing risk of disease and depression. Failure to incorporate health-focused lighting into regulations and common practice disadvantages society and developers alike.