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

Introduction: The rate at which a successive light stimulus appears to be steady and continuous is called as the critical flickering fusion frequency (CFFF). It is expressed in Hz and is referred to as the threshold frequency. It provides the information about CNS activity and arousal as well as measures the discrete sensory events happening in the central nervous system. To perceive the flickering light eye and brain have to work simultaneously and have to act together. The CFFFR was measured using critical flicker fusion apparatus. The study aimed to measure critical flicker fusion frequency and to measure the effect of age, gender, sleep and display screens on critical flicker fusion frequency Material and methods: The study was done in the department of Physiology, Maharishi Markandeshwar Medical College and hospital, Solan, HP after taking institutional ethical committee clearance. A total of 1000 apparently healthy subjects were recruited from the institute which included the students, faculty, non teaching staff and nursing staff. Critical flicker fusion frequency was measured using Flicker Fusion apparatus (FF-705): Medicaid Ambala.The critical flicker fusion frequency threshold was noted after explaining the procedure in their native language and obtaining consent. The data collected was analyzed stastically. Results: We found a significant difference in the values of CFFFR between the younger age group and among the older age group. CFFFR and age are indirectly proportional to each other with increase in age there is decrease in the value of CFFFR. The value of CFFFR was found to be higher in individuals with a normal sleep pattern and duration compared to those having less sleeping hours Inadequate sleep also has been shown to decrease the motor functioning, decreased learning ability, poor productivity and shortened memory. CFFFR was higher in individuals playing games compared to those who were using display screens normally, in addition to it those individuals who were playing instructive games had a higher CFFRT than those playing quest games. Conclusion: In this study we measured the critical flicker fusion and the factors that have a role in increasing or decreasing the CFFFR threshold. A simple and non invasive procedure helps in finding the harmful effects of various factors like age gender sleep disturbances or over usage of display screens on retina and central nervous system.