An investigation of light diffusion in x-ray intensifying screens and the prospects for improvement by confining light spread with a special structure are reported. Light diffusion in CaWO4 screens was studied theoretically using computer simulation. The proportion and spatial distribution of light emerging from different depths in the screen were calculated. The introduction of narrow gaps in the screens made it possible to improve these proportions and distributions. The gaps improved the line spread functions, the screen efficiencies, and the average contribution of the absorbed quanta to the light output.