A method for manufacturing an optical lens, includes the steps of providing a blank (1) which includes an upper surface and a lower surface (33) for forming first and second lens surfaces (2), an edge surface (4) forming a first mechanical positioning reference point and a ramp portion (5) provided between the edge surface and the upper surface, which forms a second positioning reference point; providing a positioning ring (10) including a cavity defining an inner contour (20) concentric with the edge surface which forms a first complementary control reference point and a shoulder (21) forming a second complementary control reference point; fitting the blank into the cavity, the edge surface being in contact with the inner contour and the ramp portion being in contact with the shoulder; and locking the blank in position on a locking and supporting pin, the ring then being positioned there between.