Computerized device for critical flicker fusion frequency determination

摘要

The critical fusion flicker frequency of the human visual system is the threshold sensitivity for a sine wave-modulated patch of monochromatic flickering light measured as a function of its temporal frequency and average luminance level. The critical flicker fusion frequency changes in different ocular and non-ocular conditions, for example: high-myopia, AMR, glaucoma, schizophrenia, after alcohol intake, fatigue. A computerized test for critical flicker fusion frequency determination was developed. Visual stimuli are two monochromatic LED light sources that are connected to a microcircuit driven by a computer program. The control of the device is realized through the parallel port of the PC. During the test a patient has to choose which one of two light sources is flickering. The critical flicker fusion frequency is determined by a psychophysical procedure, where the stimulus frequency that showed detection probability 75% is considered as threshold.