An optical apparatus (10) for an optoelectronic sensor (100, 200) which has at least one lens (14a-b), wherein a further optical element (18) is provided in the beam path of the optical apparatus (10) for extending the depth of field, wherein the optical element (18) is made and/or arranged such that a part of the beam path remains free and thus generates a first depth of field; and wherein the optical element (18) has a planoparallel zone which only covers a part of the beam path of the optical apparatus (10) and thus generates a second depth of field.