In this investigation, photo-induced birefringence of Pb3O4-Bi2O3-B2O3 glass ceramics doped with varying content of CuO (ranging from 0.2 to 1.0 mol%) is presented. The photo-induced birefringence (PIB) exhibited a delayed relaxation process lasting few seconds and indicated that the anisotropic photorefractive (PR) effect significantly exceeded the fast Kerr effect. Photorefractive birefringence reached a maximum at a CuO concentration of 0.2 mol%, likely due to enhanced depolymerization of the glass ceramic network that reduces the phonon losses. This is ascribed to the predominant fraction of Cu2 + ions occupying octahedral ( O h ) sites and acting as modifiers. Increasing the CuO content further, up to nearly 0.8 mol%, the magnitude of photorefractive birefringence is observed to reduce. Phonon losses increase because a higher proportion of Cu+ ions occupy tetrahedral ( T d ) positions within the glass ceramic in this concentration range, resulting in stronger interactions between different structural groups in the material. Electrical conductivity and ultrasonic measurements corroborate this finding. Additionally, these glass ceramics were found to be composed of anisotropic CuBi2O4 crystal phases, which enhance their photorefractive (PR) properties. Notably, compositions containing approximately 0.2 mol% CuO demonstrate optimal PR efficiency and are promising candidates for practical applications.