A research team asked 22 volunteers aged 17 to 42 to use electronic devices as usual every night for two weeks, but wore blue-light blocking glasses for three hours before going to bed, and found that their evening melatonin levels increased by about 58%  The increase was even greater than the change brought about by taking melatonin supplements  The volunteers felt sleepy eyes improved, fell asleep faster, and slept longer overall  The largest source of blue light, the researchers said, was sunlight, but most LED-based devices also emit blue light, and artificial blue light activates responses to melatonin  Inhibits intrinsically light-sensitive retinal ganglion cells, thereby interfering with sleep
The researchers recommend using less electronic devices before going to bed, or wearing blue light blocking glasses
Not Wearing Blue Light Blocking Glasses Before Bed Can Increase Melatonin Levels Overall