1. A method for detecting face direction, the method comprising: receiving a face image of a person; determining whether the person is wearing glasses, based on the face image; determining whether the number of reflection points of light in a glasses region of the face image is four or more at the time of detecting the glasses region; aligning the reflection points of light in order of size, upon determining that the number of reflection points of light is four or more; detecting two virtual images of the light, based on the aligning; and detecting a face direction vector based on the two virtual images of the light.