Rabbit, monkey, and human ocular reactions to the instillation of a 5% soap solution and a liquid household cleaner were graded and compared according to a scoring system based on the use of slit-lamp biomicroscopy and fluorescein, and also according to the commonly used Draize visual observation method. Reactions in monkeys were more comparable to humans than were those seen in rabbits, based on biomicroscopic observations. While the findings reported in this study must be considered a pilot effort, comparison of the responses of the three species evaluated revealed that monkey eyes, when graded according to the proposed scoring system, more accurately predicted the nature of the response found in humans. © 1969.