Definitions of vision:

• noun:   the perceptual experience of seeing

  Example: "The runners emerged from the trees into his clear vision"

• noun:   a vivid mental image

  Example: "He had a vision of his own death"

• noun:   a religious or mystical experience of a supernatural appearance

  Example: "He had a vision of the Virgin Mary"

• noun:   the ability to see; the faculty of vision
• noun:   the formation of a mental image of something that is not perceived as real and is not present to the senses