Hollow needle for instrument for destroying eye lens and for sucking up emulsion of infusion fluid and lens residue

摘要

A cannula (12) has an operating end (16) for the eye lens, and a lumen section (14). A wider section is connected to the lumen part of the cannula near its operating end. The internal cross sectional surface of the cannula is larger inside the wider part than in the lumen part. The wider part is formed by a single cylindrical expansion duct (18) whose diameter is larger than the diameter of the lumen part. The expansion duct is concentric with the lumen part of the cannula. The inner surface (20) of the expansion duct leads via a radial transfer surface (22) into the inner surface (24) of the lumen part of the cannula.