The high energy and powers of lasers offer a tool for noninvasive alteration of anterior introcular tissue. Specifically, iridotomy and trabeculotomy are possible. This has importance for glaucoma patients because of the potential improvement of surgical outcome and reduced surgical morbidity. The aim of this project is a systematic evaluation of laser effects in simian (rhesus) eyes and the application of promising systems and procedures to human glaucoma eyes under controlled conditions.