1. A method for eyelid shape estimation, comprising: under control of a hardware processor: detecting a pupillary boundary of an eye using an edge detector; determining an eye pose of the eye using the pupillary boundary, wherein an eye pose coordinate system of the eye pose comprises an azimuthal angle and a zenithal angle of the eye relative to a resting orientation of the eye, wherein a functional relationship between the eye pose coordinate system and an eyelid shape coordinate system comprises a mapping matrix, and wherein the eyelid shape coordinate system comprises a horizontal shift, a vertical shift, and a curvature of the eyelid; estimating an eyelid shape of the eye based at least in part on the eye pose and the functional relationship, wherein the functional relationship relates the eye pose to the eyelid shape; and fitting a parabolic curve of an eyelid shape of the eye based on the eyelid shape.