The Eyes That Betray the Mind: Vergence Movements as an Unguarded Signal of Cognitive Effort
Emerging research suggests that vergence eye movements—the subtle rotations that align both eyes on a target—may reveal the brain's cognitive state long before any conscious awareness surfaces. Unlike more familiar oculomotor metrics, vergence operates largely beyond voluntary control, positioning it as a uniquely candid biomarker for mental fatigue, decision-making strain, and neurological change. The implications reach from aviation safety to clinical neurology.