How can reflections in windows and eyeglasses produce apparent UFO sightings?

Reflections in windows and eyeglasses can contribute to apparent UFO sightings by creating superimposed images. When a person looks through these surfaces, light from a distant source—such as a bright star or planet—may reflect off the glass and appear to hover or move in the observer's field of vision, superimposed over the background scene.12

Because these reflections can shift as the observer moves their head or changes their viewing angle, they may be misinterpreted as an object performing unnatural or sudden motions. This effect is compounded by the fact that human visual perception of distance and speed is highly unreliable when observing objects against a blank sky, as there are no reference points to gauge scale or depth. Consequently, these optical illusions, along with the psychological tendency to interpret ambiguous visual stimuli as significant, account for many reported sightings of unidentified flying objects.12