Elastic hinge for eyeglass frames, which comprises an articulation screw engaged in the holes of two articulation elements. The articulation screw comprises a shank provided with a narrow portion, which is engaged in the hole of a first tab of an articulation element, and with an enlarged annular portion, which forms a step and is engaged in the hole of a head portion of the other articulation element. The articulation screw assumes an end stop position, in which it is tightened and aligned with the hinging axis, and a blocking position, in which it is loosened and is tilted with respect to the hinging axis in response to the elastic force exerted by an elastic device, such that the step of the articulation screw interferes with the edge of the hole of the first tab of the articulation element, preventing a further unscrewing of the articulation screw.