A needle 10 for a surgical instrument for removal of diseased or unwanted tissue comprises a hollow elongate needle shaft 12 having a needle tip 14 for cutting tissue at a distal end of the needle shaft 12. The needle tip 14 is flared in at least one plane and has a flattened posterior lip 16 and a curved anterior lip 18 to produce a substantially D-shaped tip mouth 20 in a plane that is substantially orthogonal to a central longitudinal axis C—O—C′ (the needle axis) of the needle 10. A major axis A-A′ of the tip mouth 20 is larger than an outer diameter of the needle shaft 12 and a minor axis B—B′ is smaller than the major axis A-A′. The asymmetry of the tip mouth provides improved cutting action during phacoemulsification.
