Flickering light ruins reading and productivity

I found that reading under a flickering light environment can cause eye fatigue and deteriorate my outcome so much(decrease in half eg. from 20 pages to 10 pages per day!).

Flickering light comes from an artificial light source that uses electricity to produce light such as a fluorescent lamp, cheap LED lamp, or even some type of display screen such as OLED, cheap IPS, etc. However, the flickering frequency is usually faster than the brain can notice but when your eye has to focus under such a light it has to work tiredly to adjust the lens to keep up focusing under that environment, causing eye fatigue and ruining the productivity in half.

However, not all of them produce flickering light, you can look at the labels which usually are non-flickering light, eye comfort light, etc. Moreover, you can detect it yourself easily with your smartphone camera.

• I found that I can detect light flickering by using pro mode(not normal mode) in the smartphone camera by setting the shutter speed to as fast as it allows; for my phone, it is 1/4000.

For some display screens, especially laptop and smartphone displays, you can search for its information before buying at notebookcheck.net this site produces a lot of accurate information about the specifications of many laptops & smartphones which also includes the details of display flickering.

• However, I also found that the display flickering at a very high frequency of more than 10000Hz (eg. my MacBook Pro is also flickering at 14880Hz) is comfortable to use and has no difference in productivity (and can't be detected with my smartphone) when compared to a laptop with no flickering display.
• The flickering of the display is usually caused by the dimming technology chosen to produce the display. The cheaper will just use the method called PWM which will simply alternate between on and off of the backlight screen in high frequency to trick the brain when the user dims the screen (the more dimming - the slower alternating - the more the eyes fatigue). The more expensive display will use DC dimming which will decrease the screen brightness by decreasing in the voltage power which will cause real dimming of screen brightness and much less eye fatigue.

When flickering light is inevitable

• I found that under the flickering light condition, reading on a tablet or screen is 'significantly' better(I can read much more!) than on a physical book or an e-reader(Kindle Scribe).
  • It may be because the screen emits the light itself so the flickering light environment doesn't have much influence on reading.
  • Conversely, Kindle Scribe which normally depends on the light of the environment will get much more deterioration by the flickering light condition.
  • The little solution is increasing the brightness of the screen or e-reader to decrease the influence of a flickering light environment or using a portable non-flickering light lamp. However, this will just slow down the eye fatigueness, but eventually, you still got it.
  • The best solution is to completely avoid a flickering light environment.