#$%^&*AU2007203547B220130919.pdf#####Abstract In one aspect, the present invention provides a diffractive ophthalmic lens (e.g., a diffractive IOL) that includes an optic having an anterior surface and a posterior surface, where the optic provides .a far focus. A frustrated diffractive structure comprising a plurality of diffractive zones is disposed on at least one of those surfaces so as to provide a near focus. Each zone is separated from an adjacent zone by a zone boundary that imparts an optical delay to the incident light. Further, at least two consecutive zone boundaries are configured such that a difference between their associated phase delays for at least one wavelength of the incident light is greater than about % wavelength so as to direct a portion of the incident light to a location between the near and far foci.1/5 10 FIG. IA .12( 0 ADJUSTING PHASE (STEP HEIGHT) 14 16 OF CENTRAL ZONE CREATES AN INTERMEDIATE FOCUS 20. DISTANCE FOCUS NEAR FOCUS FIG. 1B 22 12 14 16 26 24b 18 20 - - -- - ------ --- --- 20 24a 26 24b 22
