Critical Flicker Fusion Frequency: Effect of Age, Gender, Sleep and Display Screens

ABSTRACT

Introduction: The rate at which a successive light stimulusappears to be steady and continuous is called as the criticalflickering fusion frequency (CFFF). It is expressed in Hzand is referred to as the threshold frequency. It providesthe information about CNS activity and arousal as well asmeasures the discrete sensory events happening in the centralnervous system. To perceive the flickering light eye and brainhave to work simultaneously and have to act together. TheCFFFR was measured using critical flicker fusion apparatus.The study aimed to measure critical flicker fusion frequencyand to measure the effect of age, gender, sleep and displayscreens on critical flicker fusion frequencyMaterial and methods: The study was done in the departmentof Physiology, Maharishi Markandeshwar Medical Collegeand hospital, Solan, HP after taking institutional ethicalcommittee clearance. A total of 1000 apparently healthysubjects were recruited from the institute which included thestudents, faculty, non teaching staff and nursing staff. Criticalflicker fusion frequency was measured using Flicker Fusionapparatus (FF-705) Medicaid Ambala.The critical flickerfusion frequency threshold was noted after explaining theprocedure in their native language and obtaining consent. Thedata collected was analyzed stastically.Results: We found a significant difference in the values ofCFFFR between the younger age group and among the olderage group. CFFFR and age are indirectly proportional toeach other with increase in age there is decrease in the valueof CFFFR. The value of CFFFR was found to be higher inindividuals with a normal sleep pattern and duration comparedto those having less sleeping hours Inadequate sleep also hasbeen shown to decrease the motor functioning, decreasedlearning ability, poor productivity and shortened memory.CFFFR was higher in individuals playing games compared tothose who were using display screens normally, in addition toit those individuals who were playing instructive games had ahigher CFFRT than those playing quest games.Conclusion: In this study we measured the critical flickerfusion and the factors that have a role in increasing ordecreasing the CFFFR threshold. A simple and non invasiveprocedure helps in finding the harmful effects of variousfactors like age gender sleep disturbances or over usage ofdisplay screens on retina and central nervous system.