Granulated compounds based on polystyrene with hollow glass microspheres in different proportions were made on a twin-screw extruder. Microspheres were added to polystyrene composition in order to get light-diffusing material with optimal proportion of light transmission and light diffusion properties. The microspheres showed stability due to increased strength in processes. Adding the microspheres led to an increase in the light diffusion factor and to a reduction in the light transmission factor and the material density. The filler gave light diffusion properties to polystyrene in the research doses, whereas the light transmission factor reduced to the acceptable value. The microspheres may be researched additionally for giving light diffusion properties to polymeric materials, used in light engineering.