The visibility of stroboscopic effects in individuals with myopia

This study investigates how myopia affects the visibility thresholds of stroboscopic effects, which are visual phenomena caused by the pulse width modulation (PWM) of LEDs. These effects can be intensified by improper operational parameter settings. Through visual experiments with myopic participants, this study examines how these effects vary under different parameters. We used a modulated LED light source with a 4500 K correlated color temperature to illuminate a rotating black disk with a white dot. The LED modulation was controlled by a square waveform with frequencies from 100 Hz to 4200 Hz and various duty cycles. Participants perceived stroboscopic effects at a speed of 4 m/s and an illuminance of 500 lx. Using the method of constant stimuli, we identified 50 percent detection thresholds under various conditions. Based on our experimental setup and data analysis, this study introduces a model that characterizes the relationship between absolute visibility thresholds and duty cycles for myopic individuals. The model demonstrates its predictive capability by extrapolating thresholds based on data obtained from the 10 % duty cycle. These results provided valuable information for the design of luminaires avoiding stroboscopic effects, particularly for those with myopia.