What is a moment of clarity?

A moment of clarity is when you suddenly get a deep understanding of some truth that's been out of reach for you. When your vision becomes unclouded and focused by a mad rush of what has been called an epiphany or revelation. People suffering form addictions use this phrase to refer to a moment when they are not being effected by their substance and can "see" or understand clearly the nature of their problem and finally realise the need to stop and get help. A moment of clarity from whatever is making it cloudy.