51.1: Effect of PWM Dimming Frequency of OLED Smartphones on Visual Fatigue
Level 3 - non-randomized controlled study
Controlled laboratory experimental study; randomization not specified in abstract (graded by design analogy)
OpenAlex W4385521653 · doi:10.1002/sdtp.16308
What was done
Participants viewed OLED smartphone displays in a dark environment for approximately 35 minutes across different dimming conditions, including pulse-width modulation (PWM) frequencies ranging from 360 Hz to 1920 Hz and a direct-current (DC) mode. Visual fatigue was assessed using both subjective ratings and objective measurements.
What was found
The abstract reports no statistically significant differences in either subjective visual fatigue ratings or objective fatigue measurements between any of the tested PWM frequencies (360 Hz to 1920 Hz) or the DC dimming mode. No quantitative values or p-values were provided in the abstract.
Why it matters
Display manufacturers frequently advertise high-frequency PWM or DC dimming as superior for eye comfort, but these findings suggest that under brief, dark-room viewing conditions, dimming frequency may not meaningfully alter short-term visual fatigue.
Limits
The abstract does not disclose the sample size, participant demographics, specific objective measurement tools, or exact statistical metrics. Exposure duration was short (approximately 35 minutes), precluding conclusions about chronic or longer-term smartphone use.
Cited by
- supports OLED iPhones released after the iPhone 11 use pulse width modulation flickering at approximately 400 Hz to control screen brightness.