The fusion frequency of flicker (FFF) depends upon the condition of all visual pathways, and decrease of the FFF by lesion in various parts of the visual pathways has been demonstrated. Yet, there is strong evidence that in the case of intact ocular structures the FFF is determined in the occipital cortical centers. The evidence includes photodriving, decrease of the FFF in brain pathology, binocular summation effect, and reflex changes, and it was reviewed by Simonson and Brozek.1 The reflex changes of the FFF are of particular interest for experimental differentiation between peripheral and central components of the visual pathways, because diagnostic tests could readily be developed on this basis. In an earlier study on the effect of caloric vestibular stimulation, a statistically highly significant differentiation between 16 normal subjects and 16 patients with postconcussion syndrome was obtained.2 The FFF decreased in all normal subjects and increased in
SIMONSON E. Contralateral Glare Effect on the Fusion Frequency of Flicker. AMA Arch Ophthalmol. 1958;60(6):995–999. doi:10.1001/archopht.1958.00940081015003
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