Method steps for correcting vision in an eye that uses a customized phakic IOL composing: (1) measuring one or more wavefront aberrations of the eye: (2) designing a wavefront-customized correction profile for an Intraocular Lens (IOL); (3) creating a customized IOL with the customized correction profile; and (4) implanting the customized IOL in the eye. Alternatively, an uncorrected IOL is first implanted and aligned in the eye, followed by in-situ scanning a femtosecond laser spot across the implanted IOL to locally change the Index of Refraction of the IOL material and create an in-situ customized IOL.