Accuracy of Steady Ocular Fixation, and Speed and Accuracy of Saccadic Eye Movements as a Function of Task Visibility Level

Abstract

Study of visual performance data obtained under conditions of simulated or real visual work has suggested that, in addition to the visual sensory process involved in performing the Landolt ring tasks, there must also be important processes involving the oculomotor mechanisms of vision responsible for the speed and accuracy of saccadic eye movements and the maintenance of accurate ocular fixation in the momentary fixational pauses during which Information is obtained about the task. Direct recordings of these two oculomotor processes have been made with an exotic computer-driven equipment assemblage, and the performance of each process has been shown to improve as a function of increased task visibility. A quantitative model has been developed which will make It possible to calculate performance effectiveness of the two oculomotor processes for different task luminances for tasks of known equivalent contrast, C̃. The method has been shown to apply so long as the lengths of ocular saccades do not exceed 3 degrees, a limitation which is not believed to be exceeded in most lighting applications.

Additional information

Notes on contributors

H. Richard Blackwell

Institute for Research in Vision, Ohio State University, Columbus, Ohio. Dr. Sinton is now with the Sandia Corporation, Albuquerque, New Mexico.

David J. Sinton

Institute for Research in Vision, Ohio State University, Columbus, Ohio. Dr. Sinton is now with the Sandia Corporation, Albuquerque, New Mexico.