Short-pulse neodymium: YAG clinical laser systems permit noninvasive incision of transparent intraocular structures. Selection and safe use of these photodisruptors, however, require a limited understanding of certain basic physical principles. These principles are reviewed and applied in a series of optical experiments designed to study the performance and safety of clinical, short-pulse laser systems. The results of these experiments are presented, in addition to an analysis of current and proposed photodisruptors.