A method (400, 500, 600) for eyelid shape estimation, comprising: under control of a hardware processor: generating an eye-box over an eye in an eye image, wherein the eye-box has two vertical edges (124a1, 124a2), an upper edge (124b1) and a lower edge (124b2), wherein each of the vertical edges (124a1, 124a2) is tangent to a limbic boundary of the eye, wherein the upper edge (124b1) overlays a portion of an upper eyelid of the eye, and wherein the lower edge (124b2) overlays a portion of a lower eyelid of the eye; generating a plurality of radial lines extending from a center of the eye-box to the upper edge (124b1) or the lower edge (124b2); determining more than three candidate points on the plurality of radial lines intersecting a same eyelid detected, using an edge detector, wherein the candidate points (136a, 136b) comprise points with local maximum derivatives and with largest distance from the center of the eye-box, along the plurality of the radial lines; determining a parabolic fit curve (140a, 140b, 140c, 140d) from the more than three candidate points or a subset of three candidate point of said more than three candidate points, wherein the parabolic fit curve (140a, 140b, 140c, 140d) is an estimation of an eyelid shape of the eye in the eye image; determining a score of the parabolic fit curve (140a, 140b, 140c, 140d) is above a threshold score, wherein determining the score of the parabolic fit curve is above the threshold score comprises determining a number of the more than three candidate points that intersect the parabolic fit curve or determining a number of the more than three candidate points that are within a threshold distance of the parabolic fit curve (140a, 140b, 140c, 140d); and determining that the parabolic fit curve (140a, 140b, 140c, 140d) is a preferred estimation of the eyelid shape of the eye in the eye image. generating an eye-box over an eye in an eye image, wherein the eye-box has two vertical edges (124a1, 124a2), an upper edge (124b1) and a lower edge (124b2), wherein each of the vertical edges (124a1, 124a2) is tangent to a limbic boundary of the eye, wherein the upper edge (124b1) overlays a portion of an upper eyelid of the eye, and wherein the lower edge (124b2) overlays a portion of a lower eyelid of the eye; generating a plurality of radial lines extending from a center of the eye-box to the upper edge (124b1) or the lower edge (124b2); determining more than three candidate points on the plurality of radial lines intersecting a same eyelid detected, using an edge detector, wherein the candidate points (136a, 136b) comprise points with local maximum derivatives and with largest distance from the center of the eye-box, along the plurality of the radial lines; determining a parabolic fit curve (140a, 140b, 140c, 140d) from the more than three candidate points or a subset of three candidate point of said more than three candidate points, wherein the parabolic fit curve (140a, 140b, 140c, 140d) is an estimation of an eyelid shape of the eye in the eye image; determining a score of the parabolic fit curve (140a, 140b, 140c, 140d) is above a threshold score, wherein determining the score of the parabolic fit curve is above the threshold score comprises determining a number of the more than three candidate points that intersect the parabolic fit curve or determining a number of the more than three candidate points that are within a threshold distance of the parabolic fit curve (140a, 140b, 140c, 140d); and determining that the parabolic fit curve (140a, 140b, 140c, 140d) is a preferred estimation of the eyelid shape of the eye in the eye image.