(from Greek νυκτός - nuktos, genitive of νύξ - nux, “night” and φόβος - phobos, “fear”) a phobia characterised by a severe fear of the darkness. It is triggered by the brain’s disfigured perception of what would or could happen when in a dark environment.
Despite its pervasive nature, there has been a lack of etiological research on the subject. The fear of darkness (nyctophobia) is a psychologically-impacted feeling of being disposed from comfort to a fear-evoking state. The fear of darkness or night has several non-clinical terminologies—lygophobia, scotophobia and achluophobia.