Call it something that kids would have to live with, people have made it a habit to have the lights on when they sleep, a type of fear where most would consider is really psychological in nature. While it may be something funny in the eyes of some, it is a reality that people cannot sleep conveniently when they are in the dark.
For people who may find they sleeping alone, this may not pose to be a problem. But for others who cannot seem to sleep with the lights on, it would be up for debate. This is perhaps one reason why night lights were introduced.
While it may not shed the light that most people would want in their room, the fact remains that people would want to see where they are and what things are around them, all visualized when they open their eyes at any point during their sleeping period.
Further reading: The Light at the End of the Tunnel
