An important complication of paracentesis with disposable needles is injury to the lens being caused by the intracocular part of the needle. The new needle has a locking mechanism which prevents its penetrating too deeply into the eye and thus reduces the danger of lens injury. The tip of the needle has been extended in the shape of a lance to reduce the pressure during the puncture of the cornea and to avoid the Seidel phenomenon. The needle can be combined with a tuberculin syringe or pipette. It is superior to disposable needles, particularly in situations in which unexpected movements must be taken into account, i.e. during paracentesis in children, paracentesis where assistants are involved or during cumbersome manipulations.