2 years ago this photo floated around social media in Hawaii and till today we are still looking for the owner in which multiple wall posts claimed that it’s a real photograph taken from a cropped out the group picture at a school after an end of a night event.
Have you ever notice shadows seen at the corner of your eyes which can happen at any time day or night? Of course, some people believe that shadow people and shadow ghosts exist as genuine paranormal phenomena. There are reports of shadow ghosts seen when looking straight ahead. Here is an account of shadow ghost case which does not appear to involve corner of the eye phenomena. One possible explanation for shadow ghosts seen in direct vision is actual shadows! Shadow ghosts are also sometimes reported in photographs and videos (see here). These are usually photographic artifacts.
However, where shadows are seen only in peripheral vision, the explanation given above must certainly be considered. If people are convinced that they are living in a haunted house, they may notice such natural phenomena more acutely than usual, sensitised to the idea by psychological suggestion.
An interesting point about shadow ghosts is that many are typically seen to be moving (if they weren’t they probably wouldn’t be noticed). There are motion illusions, related to peripheral vision, that may account for certain specific sightings. The ‘peripheral drift illusion’ occurs when you observe an object with alternating black and white (and sometimes grey) lines (or rectangles), or something resembling that situation. When such objects are observed in the peripheral vision, anomalous motion may appear. In ‘real life’ cases this might occur in a semi-dark situation with fence posts, railings, stair banister spindles or wheels, particularly if they are painted white. The illusion is thought to be caused by the way our brains detect motion in our visual fields.