Continuous wave argon laser energy has been utilized to treat persons with angle closure glaucoma by making laser iridotomies. This same energy has been employed to lower the intraocular pressure of monkeys and humans by directing the laser beam to the ciliary body in order to cause its destruction and to the trabecular meshwork to produce trabeculotomies. During the past year we have also begun construction on a Q-Switch ruby laser whose beam is directed through the optical system of a Zeiss biomicroscope. We plan to complete the refinement of this instrument and conduct animal and human experiments to test its reliability in the production of iridotomies and to examine its capability to cause a decrease in the intraocular pressure by destruction of the ciliary body and by creation of trabeculotomies.