A work tip for a surgical hand piece has a solid blade connected to a source of ultrasonic energy in the hand piece. The knife has grooves in its surfaces. The work tip further including an irrigation and aspiration tubes extending along opposite surfaces of the blade and being at least partially within the grooves. The blade has a collar adjacent its distal end and at least the aspiration tube extends ends at a distance from the collar. The edges of the collar are made sharp enough to emulsify cataract tissue when vibrated at ultrasonic frequencies so that occlusion of the aspiration tube is prevented.