Humans are very visual beings – half of our brains are devoted to processing visual information, and we rely heavily on visual cues for almost everything. This is one of the reasons why different wavelengths of light can affect us so much.
In the past few years, Many studies have shown that certain wavelengths that we perceive as blue light can affect the production of melatonin in our brain. In layman’s terms, if you stare at bluish screens before bed, you may have trouble falling asleep.
It’s not a new thing and many display and smartphone manufacturers have built in filters to combat this effect. For example, Apple introduced an iOS feature called Night Shift in 2016, which changes the color temperature of the screen to warmer hues after sunset.
“There were no differences between the three groups in the entire sample.” Said Jensen. “Night Shift is not superior to using your phone without Night Shift or even without a phone.”
The study suggests that other factors are more important than blue light alone in causing difficulty falling or sleeping. These factors include cognitive engagement and psychological stimuli. In other words, what you actually do with your phone before bed is far more important than turning the night shift on or off.