Abstract A system and method for aligning a first and a second image of an eye includes making a determination of a limbus location on a first eye image and a second eye image. The limbus location of the first and the second eye images are then aligned in two dimensions. A second eye feature location is determined on the first and the second eye image. One of the first and the second eye image is relatively rotated, and a correlation is performed on the first and the second eye image at a plurality of relative rotational positions using the second eye feature location. From the correlation an optimal first and second image alignment is Identified. determine limbus location and first and second eye images -I . align limbus locations In two dimensions ,ID locate eye feature (e.g., blood vessel(s)) o ad aptive gradient filter .04L align on location and orientation of [blood vessel(s) rotate images relative to each other - /0(0 perform correlation ,o7 identify optimal alignment - D 0f adjust overall contrast and brightness (f9 determine area of importance 1' subdivide area of Importance into sectors block 112 FIG. 2A
