A treatment apparatus for surgical correction of presbyopia or defective eyesight in an eye of a patient. The treatment apparatus includes a laser device configured to treat lens tissue of the eye by irradiation of pulsed laser radiation with the laser radiation being focused on target points arranged in a pattern within the lens. An interface supplies measurement data on parameters of the eye and/or defective-eyesight data on the eyesight defect to be corrected in the eye, and defines a volume located within the lens using the supplied measurement data and defective-eyesight data, the volume being defined so as to achieve the desired correction of presbyopia or defective eyesight when removed.