A method for modifying the refractive index of an optical, polymeric material. The method comprises irradiating select regions of the optical, polymeric material with a focused, visible or near-IR laser having a pulse energy from 0.05 nJ to 1000 nJ. The irradiation results in the formation of refractive optical structures, characterized by a change in refractive index, exhibit little or no scattering loss, and exhibit no significant differences in the Raman spectrum with respect to the non-irradiated optical, polymeric material. The method can be used to modify the refractive index of an intraocular lens following the surgical implantation of the intraocular lens in a human eye. The invention is also directed to an optical device comprising refractive optical structures, wherein the refractive structures are characterized by a change in refractive index, exhibit little or no scattering loss, and exhibit no significant differences in the Raman spectrum with respect to the non-irradiated optical, polymeric material.