A system and method for ocular surgery includes a delivery system for generating and guiding a surgical laser beam to a focal point in a treatment area of an eye. Additionally, a contact device is employed for using the eye to establish a reference datum. Further, an optical detector is coupled to the beam path of the surgical laser to create a sequence of cross-sectional images. Each image visualizes both the reference datum and the focal point. Operationally, a computer then uses these images to position and move the focal point in the treatment area relative to the reference datum for surgery.