A method for blocking an optical lens (10) comprising a moving step in which the optical lens (10) is moved from a first reference position (P1) to a second reference position (P2), so as to be in contact with a blocking material (14), the blocking material (14) being in a molding block (16), the second reference position (P2) being a function of the first reference position (P1), wherein the method further comprises an orienting step in which the optical lens (10) is oriented in the first reference position (P1) and placed on a plurality of pre-located pins (18) which are vertically translated into a preset position (Z1, Z2, Z3), so that, when the optical lens (10) is placed on the plurality of pre-located pins (18), the optical lens (10) is oriented in the first reference position (P1) where the prism of the optical lens (10) corresponds to a desired prism (αf, βf, Zf).