Researchers from Brigham Young University conducted a study to learn how blue light affects the quality of sleep. Many scientists say that blue light can suppress the secretion of melatonin and prevent us from falling asleep, so experts advise to stop using computers, laptops, tablets, smartphones, or other devices before going to bed.
Manufacturers of such devices offer various "night modes" that reduce the amount of emitted blue light. However, the researchers found that using such features does not really affect the quality of sleep in any way.
This experiment involved 167 people who were divided into three groups. The first group did not use smartphones before falling asleep, the second used an iPhone with Night Shift mode turned on, and the third group used an iPhone without this feature turned on.
Sure, the quality of sleep among those who did not use smartphones was higher than among those who used iPhones before falling asleep. The rest of the groups, both who were using the Night Shift mode and those who were not, had nearly the same level of sleep.
Anyway, early studies show that blue light from LED screens and fluorescent lamps interferes with wakefulness and sleep. Therefore, scientists say we need more research on this issue.