Having noticed that many people still sleep with a light on even as adults, the creators of the Online Alarm Clock website thought it would be informative to research the subject of just how many people suffer from a fear of darkness. Achluophobia and Nyctophobia are two scientific terms used to describe phobias involving a fear of darkness or, respectively, a fear of the night.
Here's an infographic that explains why we are afraid of the dark.
(thanks Lee)
