Patent ID: 7296895
Filing Date: 2007-11-20
Classification: A61B

Abstract:
1. In a method for measuring a wavefront aberration of an eye in which a first, reference, object beam projected parallel to a known reference axis is input to the eye at a first, reference location (P 1 ) on a cornea of the eye such that the first beam is scattered from a location ( 1 ) on the retinal surface and further imaged onto a detector at a reference position (x 1 , y 1 ), and at least a sequential, second object beam parallel to and displaced a known amount (d) from the reference beam is projected into the eye at a second location (P 2 ) on the cornea, is scattered from a location ( 2 ) on the retinal surface and further imaged onto the detector at a second position (x 2 , y 2 ), such that a displacement (Δx 2−1 , Δy 2−1 ) can be measured and from which wavefront aberration information can be calculated, the improvement characterized by: inputting a third beam corresponding to each sequential second beam at an angle (α) to the reference axis that enters the cornea at the same location as each second beam (P whereby the wavefront aberration for cornea location P 2 from the third beam data is more accurate than the corresponding measurement from the second beam measurement.