Method for custom corneal corrections

A method for surgically correcting asymmetrical or non-spherical optical aberrations of an eye which comprises the steps of:

• establishing a plurality of reference volumes in the cornea of the eye;
• identifying a contribution from each said reference volume at a given depth below the surface of the cornea associated with the optical aberrations;
• determining a tissue volume in each said reference volume;
• directing an incising laser beam along a beam path into at least one of said reference volumes at a predetermined depth to photoalter said tissue volume therein and eliminate the contribution from said reference volume to the optical aberrations;
• and
• redirecting said incising laser beam into other said reference volumes to respectively photoalter said tissue volume at a predetermined depth therein and eliminate the contribution from each said reference volume to the asymmetrical or non-spherical optical aberrations.

A method for customizing corrections of asymmetrical or non-spherical distortions in the cornea of an eye, which comprises the steps of:

• creating a refractive power map for the cornea;
• establishing a reference field relative to the outer surface of the cornea to divide the corneal surface into a plurality of reference areas;
• corresponding said refractive power map with said reference field to determine a refractive power correction for each said reference area;
• extending the reference field into the cornea to create a plurality of three-dimensional reference volumes inside the cornea;
• determining the amount of tissue to be removed from each reference volume to obtain the required refractive change;
• directing an incising laser beam along a beam path through at least one of said reference areas to a focal spot at a predetermined depth along the corresponding reference volume, to photoalter stromal tissue at said focal spot;
• activating the laser to photoalter stromal tissue at a predetermined depth within the reference volume to effectuate said refractive power correction for the corresponding reference area to photoalter stromal tissue along a predetermined length of said beam path such that said incising laser beam is activated during said selectively moving step to effectuate said refractive power correction for said reference area;
• and
• redirecting said incising beam through another said reference area to photoalter stromal tissue in said another reference area.