The reason for the appearance of magnetic and optical anisotropy in garnets under the influence of spatially inhomogeneous light fields is investigated. The superposition of two coherent linearly polarized beams with either mutually orthogonal or parallel polarization vectors is considered. The resulting magnetic and optical anisotropy is related to an optical recharge of anisotropic impurity centers localized in crystal sites with different environment symmetry. The electron excitation and transitions under the influence of illumination are studied for the magnetic YIG:Co garnet and the paramagnetic CaMnGe garnet. A theoretical model of the occupancies’ kinetics of such centers is developed. The dynamics and spatial distribution of the energy of the photoinduced magnetic anisotropy for the YIG: Co as well as time and angular dependence of photoinduced birefringence in CaMnGe garnet are calculated. The results are compared with the corresponding experiments.