second operation) may be considered later. Technique Two main types of surgical procedures are in common use throughout the world. The first procedure is phacoemulsification (phaco), a method in which the lens is broken into small pieces which are removed by suction, and the second involves two types of extracapsular cataract extraction (ECCE), in which the lens is removed from its capsule and removed in one piece. In most surgeries, an intraocular lens is inserted. Foldable lenses are generally used for the 2–3 mm phaco incision, while non-foldable lenses can be placed through the larger extracapsular incision. The small incision size used in phacoemulsification generally allows sutureless incision closure. ECCE uses a larger incision of 10–12 mm and therefore usually requires stitches, and this in part led to the modification of ECCE known as manual small incision cataract surgery (MSICS), which does not usually need stitches. Cataract extraction using intracapsular cataract extraction (ICCE) has been superseded by phacoemulsification and ECCE, and is rarely performed. Phacoemulsification is the most commonly performed cataract procedure in the developed world. However, the high capital and maintenance costs of a phacoemulsification machine and of the associated disposable equipment means that ECCE and MSICS remain the most commonly performed procedures in developing countries. Cataract surgery is commonly done as day care rather than in-patient procedure as it is cheaper than hospitalisation and overnight stay, and there is evidence that day surgery has similar medical outcomes. Types of surgery There are two main types of surgical technique used in cataract surgery: Phacoemulsification and manual extraction. Phacoemulsification (phaco) is the most common technique used in developed countries. It involves the use of a machine with an ultrasonic handpiece equipped with a titanium or surgical steel tip which vibrates at ultrasonic frequency (commonly 40,000 Hz) to emulsify the lens tissue. A second instrument (sometimes called a "cracker" or "chopper") may be used from a side port to facilitate breaking the hard cataract nucleus into smaller pieces. Fragmentation into smaller pieces makes emulsification, and the aspiration of cortical material (the soft part of the lens around the nucleus), easier. After phacoemulsification of the lens nucleus and cortical material is completed, a dual irrigation-aspiration (I-A) probe or a bimanual I-A system is used to remove the remaining peripheral cortical material. Femtosecond laser-assisted cataract surgery has been reported to be safe, and may have less adverse effect on the cornea and macula