Relationship Between Critical Flicker Frequency and Age in Flicker Perimetry

Abstract

Introduction In flicker perimetry, a test target well above the limits of visibility with regard to size and luminance is presented at various fixed positions of the visual field. The frequency of the flickering target is lowered from fusion to a level at which flicker becomes perceptible. The critical flicker frequencies (CFF) are determined within the entire field of vision and a distribution pattern of CFF values is obtained which may be diagnostically significant. CFF however, is a function of target size,¹ luminance,² and retinal position,³ light-time/dark-time ratio in each flicker cycle,^3,4,5 contrast, wavelength of test light,^6,7 and age.^8,5,9 In an evaluation of flicker fields each of these parameters must be taken into consideration. The recognition of flicker does not require the perception of detail. Therefore, while acuity decreases rapidly with the distance from the center of the retina, reliable responses to flicker are