A method, apparatus and program product are presented for determining an orientation of a Landold C in an image containing a plurality of pixels. A center of the Landolt C is determined. A plurality of rays is extended from the center of the Landolt C radially outward. A plurality of distances is determined, where each distance of the plurality of distances represents a distance from the center of the Landolt C to a darkest pixel along each ray of the plurality of rays. A peak in the plurality of distances is identified. And the orientation of the Landolt C is determined based on the peak in the plurality of distances.