Patent ID: 6631991
Filing Date: 2003-10-14
Classification: A61B,A61L

Abstract:
An ophthalmic instrument comprising:a wavefront sensing illumination source producing light that is formed as a spot image on the retina of the human eye and reflected there from; and a wavefront sensor that estimates aberrations in reflections of the light formed as a spot image on the retina of the human eye, wherein the wavefront sensor including: at least one subaperture that spatially samples incident light; at least one optical element that focus each sample to a spot; and an image sensor and image processor for measuring location of said spot; wherein said image sensor captures image data of a pixel subaperture defined around said spot and provides the image data to the image processor; and wherein the image processor i) identifies a subarray of pixels around a peak in the pixel subaperture; ii) fits a predetermined function to the image data for said subarray of pixels; and iii) derives an estimate for spot location based upon location of the fit of said predetermined function.