An improved spherical coordinate system applied in oculomotor system-the possibility for rapid strabismus diagnosis

A variation of spherical coordinate system is proposed for the simplification of illustration of Listing's law. With this method, the rotation of an eye is decomposed into two independent rotations, largely simplified its math expression. The robotics method of motion matrix transformation is then applied to derive the math interpretation of primary Listing's law and half-angle rule respectively. Based on the results, a new algorithm for eyeball position and orientation measurement is proposed. In this algorithm, all the parameters can be directly measured from photos, thus makes rapid diagnosis of strabismus possible.