An optical device (2300) including a partial or incomplete optic (2320) configured operatively as an add-on (e.g., supplemental lens/optic) for an (existing) optical element or system, the partial or incomplete optic having an active area configured in relation to the optical element or system such that the partial or incomplete optic controls or changes foci of light incident upon or provided to the active area, but does not control or change foci of light bypassing optically relevant portions of the partial or incomplete optic, and associated methods for enhancing vision.
