A method of molding a lens, comprising:
- providing a peripheral gasket member comprising a surrounding wall around an axis to define a through-cavity extending along the axis, the surrounding wall having an internal circumferential ridge portion protruding inwardly towards the axis from an inner side of the surrounding wall in a manner so as to partition the surrounding wall into an upper wall portion and a lower wall portion respectively above and below the internal circumferential ridge portion with respect to the axis,
- wherein the internal circumferential ridge portion comprises
- a first ridge-flank directed in a first direction corresponding to a direction extending along the axis from the internal circumferential ridge portion to the upper wall portion, and
- a second ridge-flank directed in a second direction corresponding to a direction extending along the axis from the internal circumferential ridge portion to the lower wall portion;
- disposing a film at the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member with a segment of a peripheral border region of the film in abutment with the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member;
- disposing an annular member over the segment of the peripheral border region of the film in a manner so as to retain the segment of the peripheral border region of the film between the annular member and the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member;
- disposing a first mold part with a circumferential edge of the first mold part in abutment with the upper wall portion of the peripheral gasket member;
- disposing a second mold part in an opposing manner with respect to the first mold part and with a circumferential edge of the second mold part in abutment with the lower wall portion of the peripheral gasket member;
- and
- filing a molding cavity, defined by the peripheral gasket member, the first mold part and the second mold part, with a liquid molding material for molding the lens,
- wherein:
- the first ridge flank of the internal circumferential ridge portion of the peripheral gasket member comprises a concentric-stepped profile in a radial direction with respect to the axis, the concentric-stepped profile comprising an outer step and an inner step, wherein the inner step is radially closer to the axis than the outer step,
- disposing the film further comprises disposing the segment of the peripheral border region of the film to abut the inner step of the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member,
- disposing the annular member further comprises disposing the annular member with an outer border region of the annular member to cover the outer step of the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member and an inner border region of the annular member to overlap the segment of the peripheral border region of the film in a manner so as to retain the segment of the peripheral border region of the film between the inner border region of the annular member and inner step of the first ridge-flank of the internal circumferential ridge portion of the peripheral gasket member.