The pneumatic blocking support which is used to block an optical lens (200) on a machine or device has means (3) for fixing it on a corresponding element of the machine or device. The blocking means comprise a central cavity (8) and a joint (9) having at least one annular part (9) against which the lens rests in order to define a depression chamber (11) with said cavity and joint. The blocking means comprise stop means (10) which are created in order to provide the optical lens with a rigid seat after the elastic compression of the joint.
