Numerous studies have been performed to determine the relations between both the refractive error and the ocular anatomy and the ethnicity or geographic residence of people. The investigated parameters include the ocular axial length, the radius of corneal curvature, the corneal asphericity, and recently, the high-order wavefront aberration. In this paper, we review the reported measurements of these 4 ocular parameters with their dependences on ametropic condition. The distribution of each of the 4 ocular parameters in a large population can be observed. When presented in the same plot, the differential distributions as a function of ethnicity and gender are revealed. The knowledge of the statistical distributions could be useful in the performance evaluation of an ocular instrument/ device.