I’ve heard that blue light affects you negatively at night. What about other colors?
In: Biology
Your brain is programmed to associate yellow/orange light with sunrise and sunset (time to sleep) and blue light with daytime (time to be awake). Blue light inhibits the hormones that send you to sleep because up until the invention of electric lighting, the only time any animal would ever see blue light regularly is during the day and we evolved to be awake during the day.
Humans originally evolved in an environment where the only significant light source was the sun, and as a result our bodies are generally adapted to the daily cycle of sunrise->daytime->sunset->nighttime over and over again.
One of the ways our body stays in sync with that is, our eyes receiving blue light tells our body that it’s daytime. For the vast majority of the history of life, if there was significant blue light, that meant the sun was out. So when we’re seeing blue light, that signifies to our body that it should be doing daytime things, which generally involves being awake.
So now when we use screens that are emitting a decent bit of blue light, that subconscious part of our nervous system is getting that signal and that can trigger processes in our body that make the body ready to be awake, and subsequently not as ready for sleep. And so it can make it harder for you to fall asleep.
There’s some evidence that blue light creates this effect significantly more than other colors of light, and since everyone’s different it affects people in a wide variety of ways.
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