Blocking member and method for vacuum blocking of lens blank

The invention relates to a barrier (10) for vacuum barrier of a lens blank (30). The barrier (10) comprises a blank contact element (12) formed from a rigid fluid permeable material having an upper surface (12a) for contacting the lens blank (30). The barrier (10) further comprises a support element (14) having an upper portion (14a) tightly enclosing the blank contact element (12) on a peripheral surface (12a) of the blank contact element (12) and a lower portion (14b) adapted to engage with a gripping means for gripping the barrier (10). The stopper (10) is adapted to secure the lens blank (30) to the upper surface (12a) of the blank contact element (12) by applying a vacuum within the stopper (10) to provide a suction force through substantially the entire upper surface (12a) of the blank contact element (12) to suck the lens blank (30) to the upper surface (12a) of the blank contact element (12). The invention further relates to a method for blocking a lens blank (30) and to the use of an element formed f