Light diffusing polycarbonate samples were exposed to protons fluences at levels between 10(11) and 10(16) p/cm(2). The variation of the refractive index and color intensity with the proton fluence has been studied. The results show that the polycarbonate samples acquire color changes under proton irradiation. Furthermore, thermogravimetric analysis has been performed. It was found that both the onset temperature and activation energy of thermal decomposition are affected by the proton fluencies owing to the degradation and cross-linking processes. Moreover, structural property studies using X-ray diffraction, intrinsic viscosity and Fourier transform infrared spectroscopy were performed.