Editing Phacoemulsification (section)

===Aspiration===
The aspiration system is used to remove the emulsified lens tissue as it is broken down by the tip. This may be done through the handpiece, with the inlet orifice around the vibrating tip. or through a separate aspiration tip, inserted through a smaller incision.<ref name="Yow and Basti 1997" />

The pump of the phacoemulsification system can be a [[Peristaltic pump|peristaltic type]] or a vacuum transfer type. In peristaltic pumps aspiration flow rate and vacuum are independent. Vacuum is the suction force which holds cataract nuclear fragments against the phaco tip so that they can be emulsified, and draws the emulsion into the tip.<ref name="Yow and Basti 1997" /> Vacuum is the relative low pressure generated by the pump removing liquids and gas from the suction side, and the pressure difference between the vacuum pump reservoir and the ambient pressure at the inlet to the tip of the handpiece draws fluids through the aspiration ducting. When the inlet is occluded by solid material, such as a cataract fragment, the pressure difference holds the solid in contact with the tip while the ultrasonic vibration breaks up the solid to fragments small enough to pass into the aspiration ducting and be carried away by a current of ambient fluid, which must be replaced as fast as it is removed, to retain internal pressure and shape of the eye.