Summary: Light has a profound impact on every aspect of human life. In particular, the use artificial light which is related to work output consumes over 1/5th of all electricity produced in the United States. This REU project will specifically focus on how the properties of light are a dominant factor in two areas of human activity. First, students will research and determine ergonomic relationships for various light sources including light emitting diodes (LEDs). While completing this research, students will also learn about the growing field of spectrally enhanced lighting and how it can affect energy efficiency. The students will then be the given the opportunity to assist in the performance of ergonomic lighting assessments. This real world experience will provide an excellent opportunity to apply the knowledge gained to actual workplace settings. During the second phase, students will investigate how the properties of light affect power production from solar photovoltaic panels. In particular, students will investigate how the wavelength intensity distribution affects power output and efficiency of several types of solar photovoltaic panels. The research conducted will specifically provide information on how the properties of light can be changed in order to improve both work output and the overall work environment.