Today, modern luminaires almost exclusively use LED light sources in combination with optical components made of plastics. However, conventional plastics such as polycarbonate or polymethyl methacrylate are based on fossil raw materials and therefore do not contribute to a sustainable economy in lighting technology. To promote a circular economy approach in this field, it is an obvious option to investigate the applicability of bio-based plastics. One promising candidate is the biodegradable plastic polylactide, which is based purely on renewable raw materials. The main advantage of polylactide is its excellent optical properties. In general, optical plastics are exposed to high levels of electromagnetic radiation especially in applications involving LED technology. First studies demonstrate that polylactide is highly resistant to radiation-induced aging induced by such irradiation. However, the use of the material in luminaires is hindered by its thermal behavior: At temperatures above 60 °C, the material becomes cloudy. This is caused by crystallites that scatter the incident light. Therefore, various approaches are being pursued to suppress the crystallization or to adjust the crystallites to minimize light scattering. One approach is the use of bio-based additives. Initial experiments conducted with fatty acid derivatives show a reduction in opacity of the material after treatment at elevated temperature. After the optimization of the thermal behavior, dedicated optical aging experiments will be carried out to investigate the photodegradation behavior of the stabilized polylactide.