Humans can sense when someone is looking at them due to a specialized "gaze- detection system" in the brain, which has evolved as an ancient survival mechanism. This system detects where others' attention is directed by analyzing subtle cues like eye direction, head, and body position. The human eye's unique structure, especially the large, white sclera around the pupil, makes it easier to discern gaze direction, facilitating this detection even from a distance. Our peripheral vision also plays a role, allowing us to sense gaze even when not looked at directly, though with less accuracy. When uncertain, the brain errs on the side of caution and assumes being watched because a direct gaze often signals dominance or threat, making this assumption a survival advantage. This capability is deeply rooted in human social interactions and evolution, helping maintain social bonds and avoid threats. The feeling of being watched, sometimes described as a "sixth sense," stems from this subconscious processing of visual and social cues rather than extrasensory perception. It involves multiple brain regions including the visual cortex and the amygdala, integrating sensory inputs and threat assessment to generate the sensation of being observed.
