A hollow needle for an instrument used in ocular surgery for the in-vivo disintegration of organic lenses via ultrasound, having a functional part (1) and a connector part (2), with the connector part (2) having handling portions(3) and serving to attach the tool in a removable fashion to a handle, wherein the properties of the handling portions (3) change upon connection of the tool to the handle, removal of the tool from the handle, and/or upon reprocessing of the tool. In addition, a method is disclosed for the production of a corresponding medical tool.