A system and method for increasing the amplitude of accommodation and/or changing the refractive power of lens material of a natural crystalline lens is provided. Generally, there is provided methods and systems for delivering a laser beam to a lens of an eye in a plurality of sectional patterns results in the shaped structural weakening of the lens. There is also provided a method and system for determining adjustments to refractive errors in the lens of an eye relating to the treatment of presbyopia. The change to refractive error can be a predicted error or an actual error that has been determined.