A method that adds material selectively to a lens substrate and is used to produce a customized eyewear lens with optical power that is discernibly different from the optical power of the lens substrate. The method involves obtaining the lens substrate, calculating and generating an added material design to convert the lens substrate's optical power to a desired optical power for the customized eyewear lens, contacting the lens substrate with a bulk source of flowable radiation-polymerizable material, and irradiating the material with radiation that is controlled for wavelength range, energy and spatial distribution to polymerize the radiation-polymerizable material only in a selected area according to the added material design. The method does not require the use of external shaping structures to form the customized lens on the lens substrate, and the added material is integrally bonded to the substrate.