Method and apparatus for determining eye topology

Abstract

A method and apparatus for measuring the topography of the corneal and scleral regions of the eye. The measurements provide surface contours that are useful in the manufacture of scleral contact lenses.

What is claimed is: 
     
         1 .- 14 . (canceled) 
     
     
         15 . A method comprising
 generating an optical beam from a light source;   scanning the optical beam to impinge a surface of an eye along a plurality of meridian scan lines of the eye;   detecting, for a plurality of positions located along each meridian scan line, a reflected optical energy component, to thereby determine a set of distances for each meridian scan line;   capturing, at the same time as the detecting step for each meridian scan line, a two dimensional visual image of the eye associated with the respective meridian scan line, to produce a set of two-dimensional images having a two-dimensional image for each meridian scan line; and   aligning the set of two-dimensional images to generate a composite three-dimensional image of the eye, and to thereby also obtain a three-dimensional topography of the eye, and to thereby compensate the three-dimensional image and the three-dimensional topography for eye motion occurring during the scanning step.   
     
     
         16 . The method of  claim 15  additionally comprising:
 scanning the optical beam along an axis that includes a line normal to a line tangent to a point on a sclera and to a point on a cornea of the eye. 
 
     
     
         17 . The method of  claim 15  additionally comprising:
 placing, on a platform, an apparatus that performs the scanning, detecting, and capturing steps; and 
 rotating the platform about an axis that is perpendicular to an optical axis of the eye. 
 
     
     
         18 . Apparatus as recited in  claim 16  wherein the tangent line forms an angle between 27 degrees and 47 degrees relative to an axis perpendicular to a top of a pupil of the eye. 
     
     
         19 . The method of  claim 15  additionally comprising:
 fabricating a lens from the three dimensional topography of the eye. 
 
     
     
         20 . The method of  claim 15  additionally comprising:
 directing a patient to stare at a point of fixation while the patient angularly rotates their head to a different head position for each of a plurality of scanning steps. 
 
     
     
         21 . The method of  claim 20  additionally comprising:
 stitching two-dimensional images obtained for two or more head positions. 
 
     
     
         22 . The method of  claim 15  wherein the scanning step further comprises optical coherence tomography scanning. 
     
     
         23 . The method of  claim 15  wherein the scanning step further directs illumination across a portion of the eye using an illumination source and a scanning mirror. 
     
     
         24 . The method of  claim 15  wherein the composite image includes at least one of the cornea, iris, pupil, shape of the pupil, sclera, or blood vessels in the sclera.