Caelum Incognitum — The interactive encyclopedia of ufology
Afterimage
Explanations & misidentifications
After staring at a bright light the eye keeps, for a few seconds, a coloured blotch that follows the gaze and changes hue. Seen against a dark background or the sky, it can look like an object moving along with the observer. It is a common explanation for lights that “follow” someone or vanish when the eyes blink.