In phase 1 of three-phase phacoemulsification, an endocapsular nuclear emulsification technique, two intersecting grooves divide the nucleus into four quadrants. The grooves are short and involve most of the thickness of the nucleus. In phase 2, the standard irrigation/aspiration flow is reversed by a valve. Fluid enters the eye via the ultrasound tip, and aspirated tissue exits through the silicone sleeve. The critical juxtacapsular parts of the nucleus are removed with minimal risk of aspirating the capsule, and the four quadrants are separated completely. In phase 3, the free quadrants are emulsified in the center of the capsular bag. This technique helps prevent capsule rupture and might also be less traumatic to the corneal endothelium than traditional two-phase phaco.