daylight

your screen turning on &amp; off 500 times a second is not good for your brain

🧵 on light flicker

the most unnecessary and under discussed modern stressor

(send this to someone who stares at their phone too much) 

light flicker is invisible

you can't see it, but your brain feels it anyway

the most common cause of light flicker is called PWM (pulse width modulation) 

many devices and lights use PWM to control brightness

that's because it improves LED performance at low brightness, and can have more efficient power consumption

but at what cost? 

according to IEEE1789 + other research articles, the side effects of flicker are:

• photo epilepsy
• aggravation of autism symptoms in children
• migraine or intense paroxysmal headache
• eye strain: fatigued + blurred vision
• panic attack
• anxiety
• vertigo

yikes. 

the health risk of flicker is defined by:

1) the frequency --&gt; lower = higher risk
2) the modulation or flicker % --&gt; higher % = higher risk 

the most popular smartphones today use 240-500Hz PWM dimming with high modulation %'s  = recipe for eye strain + headaches

this shift to high flicker risk happened when phones moved from LCD to OLED based screens 

daylight OTOH is flicker-free: we engineered our LivePaper display to use DC dimming rather than PWM

instead of aggressive modulation (what PWM does), DC dimming generates a steady light output free of flicker

= SOOOO much easier on the eyes 

@Nsousanis check out the difference between DC dimming and PWM

PWM = invisible to our eyes but harmful to our brains

DC dimming is the obvious solution IF we want to prioritize the wellbeing of the end user 

how does DC dimming achieve this consistent light output?

DC = direct (electrical) current 

so, now that you know the difference, what do you do?

• ideally use DC dimming devices
• minimize screen time on your phone
• switch to an LCD phone or an OLED with high PWM frequency
• turn "white point" mode ON (increases duty cycle, can reduce PWM dimming)

to take the full deep dive on flicker, read our latest guide at http://daylightcomputer.com/guides/screen-flicker-101