VISUAL ACUITY WHILE ONE IS VIEWING A MOVING OBJECT

Abstract

FOVEAL visual acuity while one is viewing a moving object has received curiously little attention. In fact, the only reference to this subject which I have been able to find is a note by Langmuir¹ in which, in an effort to estimate the speed of a deer botfly, he whirled above his head a piece of solder fastened to a string and noted at what speed the piece of solder appeared blurred. I have discussed this problem.² There have been investigations of the minimum velocity perceptible as movement³ and the way in which this minimum velocity varies from center to periphery of the visual field.⁴ There have also been investigations of the minimum length of path which permits motion to be perceptible.⁵ Some have claimed⁶ that there is "visual anesthesia" while the eyes are voluntarily moving. Bethe's "Handbuch,"⁷ Duke-Elder,⁸ Troland⁹ and