Night exposure to our electronic devices, whether for work or play reduces melatonin production which is crucial for sleep. The same reason we are awake and active during daylight is reducing our sleep quality at night--Blue light.
If you must use your devices at night, like what I'm doing right now, you can reduce the blue light emitted through the following software and settings:
f.lux on your computers.
The "Night Shift" function on iOS under Settings -> Display and Brightness.
These settings increase the warmness of your screen, thereby reducing the blue light emitted by the devices and perceived by the brain.
Android OS has a number of Apps that perform similarly, and Android's "Night Mode" should be native soon.
