This is not going to be a science lesson but we do need to start with a spot of physics and biology for this to all make sense…
The physics bit: Blue light is a wavelength of light that occurs in the normal visible spectrum. It occurs naturally in sunlight but is also produced artificially by the screens of our digital devices.
The bio bit: Blue light in the morning has superb effects. It wakes you up, makes you superhero alert and gets you geared for the rest of the day. This is because blue light suppresses the secretion of a hormone called melatonin. When melatonin is high you feel sleepy. When it is low you feel awake. Blue light drops the level of melatonin and therefore wakes you up. Big time.
Now, as you can probably imagine, this is pretty wonderful during the day as we all want to be as alert and energised as possible in the daylight hours. The problem, however, comes in the evening. When we were cavemen, our bodies’ daily rhythms were guided by the sun i.e. the blue light woke you up in the morning, and when the blue light disappeared at night you felt sleepy and went to bed (or the caveman equivalent). Unfortunately today things aren’t so simple, as as mentioned above, screens also produce blue light. This means that in an evening we don’t get sleepy because our melatonin levels continue to be suppressed by the blue light from the screens from our digital devices (phones, laptops etc). This means that we are still buzzing late into the night. In fact even if we do fall asleep, studies have shown that sleep after using digital devices is incredibly disrupted because the blue light from the device continues to suppress the melatonin and makes us restless. What is even scarier is that most of us have no idea that our sleep is being disrupted – we just don’t feel all that groovy the next day, but probably attribute it to the weather, friends, school work etc.
Therefore, the advice is that we need to turn our screens off at least one to two hours before bed. There are things that can help on our devices like “night mode” that reduce the amount of blue light emitted at night (which is a great thing to use), but still the way to get the absolute best night’s sleep is to turn off your phone in the hour or two before bed, and to not expose yourself to any other screens.
Sleep is important. Without it our mood is lower, we are less-energised, our academic performance drops (dramatically) and we suffer negative health effects. We know that we’re never going to convince you all to give up your phones every evening, but if at least before exams or big tests you put the phone away before bed the chances of a good night’s sleep and better performance the next day are hugely increased. We tried it and we can’t believe the difference.
It’s essentially all about understanding the science and making it work for you. Want to wake up in the morning? Open the curtains. Want to sleep at night? Turn off the screens. Simple.