Smartphones have become a necessity for us and well, we all can’t really blame anyone for this. They do tend to solve most of our problems and that’s exactly why they are the last thing we use before we go to sleep and they are the first thing we use when we wake up. This approach is damaging, yes – damaging, to your brain. Oh and this is backed by science by the way. According to studies, sleeping with the smartphone and engaging with it even about an hour ago before you go to sleep can seriously damage your sleep quality and health in ways that will be lasting.
The following chart depicts the ways that your health is being damaged by your smartphone.
The phone comprises of a very bright blue light that helps your phone to be visible even during sunny days. This light confuses your brain into registering the light as being sunlight when you use the phone at night and thus stimulates it to remain awake. This may sound like a magical way to pull off an all-nighter, but the costs are too high.
Many of the folks would boast that they are capable of working just fine even when they are sleeping less than the recommended 7-9 hrs of sleep. However, they are wrong. You don’t work just fine when you’re sleeping less, you become conditioned in a way that you do not notice. Despite the fact that whether you’re getting enough sleep or not, if you’re spending the hour before sleep using your smartphone, then your brain ceases the production of the hormone melatonin that gives your body the ‘time to sleep’ cues.
According to scientific research, the sleep is the time when the body is in the detoxification phase and interruption of this phase can lead to a number of very serious concerns. 
A number of health risks that are associated with this include a decrease in melatonin thus resulting in less sleep and therefore, fatigue leading to shorter memory and slow reflexes. It can lead to obesity, depression and cancer.
What can you do about it? Make it a habit to put your phone away at least an hour before you go to bed. If you can put it in another room; that’d be great!
Just for me: The problem with the smartphone (and TV, and pc,…) is, that we don’t get tired from the blue light, right?
The damaging factor is getting not enough sleep overall, regardless using a smartphone, watching TV or reading a good book at night?
The exact reason the smartphone (or other display that functions on a blue spectrum screen light) is so bad is that it has been linked to the decrease in melatonin production. If you’re reading a paper book using an old school incandescent or softer fluorescent light bulb, there isn’t as much risk of chronic sleeplessness. I’ve noticed it in myself, that when I read a book or news article on my phone or kindle before bed, I don’t sleep as well, as if I read a regular b book.