Inspired by the apposition compound eyes of many dipterans, we formulated a fractal scheme to design prismatic lenses to improve the performance of silicon solar cells. We simulated the absorption of light, both directly illuminating and diffuse, using the geometrical-optics approximation. We found that properly designed bioinspired compound lenses (BCLs) can significantly improve the light-harvesting capabilities of silicon solar cells. The degree of improvement will depend on the material chosen to make the BCLs as well as the operating conditions.