In various embodiments, phacoemulsification needle may include at least first and second bending of axis and the attack of cutting edge part. The tip of the geometry may be configured to generate lateral displacement (Ux, perpendicular to axis, frequency 10 kHz and 60 kHz, the lateral displacement point tip for being less than the distal end of about 5% to 25% (such as 15%) extend to the first curved cutting edge portion tip through the end tip of a part of conical section of the axis extended between the tip of twisting vibration. It can be arrived with software and/or physical modeling and determine tip geometry.
