A cavity illumination system according to the present disclosure may include one or more illumination elements composed of a transparent or semi-transparent, biocompatible sterilizable polymer and one or more illumination sources. The sterilizable polymer operates as a waveguide. An illumination element may incorporate micro structured optical components such as for example gratings, prisms and or diffusers to operate as precision optics for customized delivery of the light energy. The micro structured optical components may also be used to polarize and/or filter the light energy entering or exiting the illumination element.