ELi5: Why do phones have blue light filters? What are those blue filters actually doing and or helping? Furthermore, should we be watching ‘blue light levels’ from other devices like TVs, monitors, etc?

Question

I think this might be a blend of the technology/engineering/biology flairs, hopefully I made this post correctly!

In: Technology

Answer 1

Our brains use blue light to help regulate our sleep patterns – when you have a large amount of blue light, your brain sends signals to your body to stay awake.

Historically, this wasn’t an issue, as the only real natural source of blue light is the sun itself. However, with the advent of modern electronics devices, we are getting blue light at all hours of the day (looking at your phone after dark) and it is causing sleep issues. The blue light filters on phones are meant to help resolve this by limiting our blue light after dark.

We should be watching blue light levels from other devices as well – most sleep doctors recommend you stop watching TV at least an hour before you go to bed to so your body stops sending ‘stay awake’ signals that can disrupt sleep.