An ophthalmic surgical control apparatus is configured to be connectable to a piezo handpiece for emulsifying an eye lens. The control apparatus includes a frequency generator having a first and a second frequency module. The first frequency module generates a first oscillation signal having a first frequency lower than the ultrasonic resonant frequency of the piezo handpiece. The second frequency module generates a second oscillation signal having a second frequency greater than the ultrasonic resonant frequency of the piezo handpiece. A frequency generator control module controls the first and the second frequency modules.
