Making a photomap of the human eye based on the spherical shape of its sclera and the circular contour of its iris

Iridology was defined as a method of diagnostic used in alternative medicine to analyze health status by studying colors, marks and signs in the sclera of the eye which according to iridologists can be demarcated into zones corresponding to parts of the human body. These are then made into “iridology charts” for comparison with photo images of a patient’s eyes. Due to the large tilt angles of the images relative to the eye’s geometrical axis, accurate comparison is not possible, and this paper suggests the use of photogrammetric methods for making a photomap for each of the patient’s eyes which is then compared to its respective iridology chart. Because of the small overlapping area between any two successive images (about 20%) and the lack of control points, we were prevented from using conventional photogrammetric methods and instead had to develop an alternative photogrammetric method based on the spherical shape of the sclera and the circular shape of the iris contour. Accuracy tests showed that this method is relatively accurate and has small residuals following the process of bundle adjustment.