CPC A61F 2/1656 (2013.01) [A61F 9/008 (2013.01); B29D 11/023 (2013.01); A61F 2009/00897 (2013.01); A61F 2240/001 (2013.01)] | 19 Claims |
1. A method for forming a zone of a Fresnel type gradient index lens in an intraocular lens (IOL), the zone having a ring shape and a predefined radial profile of optical pathlength (OPL) difference, the method comprising:
scanning a pulsed laser beam in the IOL in multiple consecutive passes,
wherein in each pass, the laser beam is scanned in concentric circles of varying radii within all of part of the zone,
wherein in each of all except a smallest one of the multiple passes, within a first radius range of the zone, an energy of the pulsed laser beam for each circle is below a predefined maximum energy and is dependent on the predefined radial profile of the OPL difference, and within a second radius range of the zone which is non-overlapping with the first radius range, the energy of the pulsed laser beam for each circle is the predefined maximum energy, and
wherein in the smallest one of the multiple passes, within a first radius range of the zone, the energy of the pulsed laser beam for each circle is below the predefined maximum energy and is dependent on the predefined radial profile of the OPL difference.
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