Flicker fusion frequency may be measured in terms of either increasing or decreasing rates at which successive visual stimuli are presented to the subject. In this work, a decreasing rate was used and flicker fusion frequency is defined as the rate at which the subject noted a change from a continuous to an interrupted sensation. It is expressed in cycles per second.
Although flicker fusion was known to be a sensitive method of examining the retina and optic pathways, it was not until 1933 that Phillips11 demonstrated its utility for examination of visual fields of several neurological patients and three normal subjects. His work was carried on and extended by Riddell,12 working with the same equipment but with modified technique. He tested 15 normal subjects at 16 points in the visual field.
Hylkema3,4 tested 33 light-adapted normal subjects at four points on the horizontal meridian, reaching 25
LOVEKIN LG, CHANDLER MR. The Range of Normal for Visual Fields by Flicker Fusion. AMA Arch Ophthalmol. 1959;62(4):588-598. doi:10.1001/archopht.1959.04220040050007