Apparatus and methods to increase the depth of field in human vision in order to correct for loss in refocusing ability. Optics variations, such as changes in thickness, shape, or index of refraction of contact lenses, intraocular implants, or the shape of the cornea or eye lens, affect the phase, or wavefront, of the light perceived by the eye. The optics variations are chosen such that the resulting optical transfer function remains relatively constant over a desired range of object distances and pupil diameters.