An intraocular lens for modifying the refractive abilities of a natural lens or an existing artificial lens in an eye to correct for vision disorders such as presbyopia, myopia, hyperopia or astigmatism. Specifically, the lens system can be configured so that it does not effect far vision, while effecting near vision using a plus lens to correct for presbyopia. The lens system includes a lens portion and fastening members, with the lens portion being movably secured to at least one of the fastening members so that the position of the lens portion can be modified with respect to the optical axis, and the overall length of the lens system can be increased or decreased.