Correction Values for IOL Power Estimates

An ophthalmic instrument comprising:

• a measurement device for measuring the aphakic optical power of a patient's eye;
• and
• a processor for performing a method comprising,
• receiving an indication of the aphakic optical power of the patient's eye from the measurement device,
• determining an intraocular lens (IOL) power value based, at least in part, on the aphakic optical power of the patient's eye,
• receiving a measured axial length value for the patient's eye,
• selecting one of a plurality of possible relationships for calculating an IOL power correction value, the selected relationship being based upon the axial length value,
• determining, with the processor, an IOL power correction value, the IOL power correction value being determined from the selected relationship and from one or more characteristics of the patient's eye, and
• applying the IOL power correction value.

An ophthalmic method comprising:

• receiving a measured axial length value for the eye of a patient;
• selecting one of a plurality of possible relationships for calculating an IOL power correction value, the selected relationship being based upon the axial length value;
• determining, with a processor, an IOL power correction value, the IOL power correction value being determined from the selected relationship and from one or more characteristics of the patient's eye;
• applying the IOL power correction value.