To accomplish so called dimming of an OLED, the smartphone's OLED display actually flash pulsed at full brightness, but because of the way the fovea of retina registers images, it appears to be dimmed, yet light sensitive ganglion that regulate our brain, sleep wake cycle, endocrine system, and other physiological responses can register these non-visible bright flashes at up to 800 hertz.
Apple, Google, Microsoft, NVIDA, Samsung since 2017 have been aware that the low cost display IC they use in mass produced smartphones, harms people by pulse flashing bright light with PWM modulation which is a fake form of "dimming" an OLED screen, when IPS LCD can simply reduce brightness of the backlight to accomplish dimming.
Under fully brightness, OLED does not flicker for dimming, so no eye problems, no brain inflammation, no eye strain, no migraine trigger, its only when dimmed that OLED to look dimmed actually flicker faster in short pulses which hyper activates our lizard brain stem system, occipital lobe, frontal lobe, mid brain, and critical brain areas regulated by optical nerve ganglion bundles that register light at up to 800 hertz.
OLED cannot be voltage dimmed because the organic chemical molecules that convert current to light in OLED RGB cells does not dim when voltage decreases, so to trick our eyes into thinking the OLED dimming, the the cheaper display IC flickers the OLED at full brightness at a faster frame rate than your brain is unable register as images, 30 FPS or up to 100 FPS when fully awake gaming on PC or driving a car and paying full attention for maximum safety.
Refresh rate on LCD does not matter in terms of human physiology, because dimming the LCD relies on dimming the backlight, which is actual dimming, not OLED pulse flashing stressing out our brain and visual system.
To save $5 per phone, they have been knowingly using an outdated display diver IC, instead of updating to an eye safe faster 8340 hertz flicker dimming that would cause no issues for anyone's eyes or brain.
Its been demonstrated scientifically that 240 hertz PWM flicker dimming OLED actually drives neurological inflammation, and in sensitive people can trigger or cause a migraine headache. In most people the flicker PWM modulation of dimming the smartphone OLED displays causes eye muscle strain, eye headaches, sore eyes, and makes peoples eyes hurt.
