First, it is essential to define a keyword:
Melatonin- A hormone, secreted by the brain, to induce rest and sleep like state. This hormone is also a potent antioxidant which helps scavenge free radicals that accumulate in the body and cause oxidative stress.
So, how does melatonin fit into sleep, and, can we manipulate this hormone?
This question is essential to our understanding of sleep, so, I suggest you watch the video above. I will also provide links for further reading below.
This setting turns all the blue, sleep-disrupting, light into Red light. The longer wavelength of the Red-light does not influence melatonin secretion.
Other applications which do the same job are:
f.lux compatible with Windows computers, Mac, Android, and IOS.
Twilight, a favorite for Android users.
The Spectrum of light and their wavelengths
Effects of blue light on the circadian system and eye physiology