Afterimage Archaeoastronomy proposes that ancient stellar mythologies, architectural alignments, and ritual cosmologies emerged from universal human visual afterimage responses to the night sky. Under dark-sky conditions, human vision does not perceive stars as isolated points, but as perceptual structures—lines, vessels, swarms, and diffuse luminous layers—generated by micro-saccades, brightness gradients, and physiological afterimage persistence. These perceptual modes explain why independent civilizations produced remarkably similar celestial narratives without cultural contact. The framework integrates four stable visual templates: Line Image: Represented by the structural formation of Orion's Belt. Vessel Image: Observed in the rectangular bowl and handle of the Big Dipper. Swarm Image: Seen in the dense clustering of the Pleiades. Layer Image: Perceived in the continuous luminous band of the Milky Way. Architectural orientations seamlessly materialize these percepts. Case studies demonstrate this integration: Giza encodes the line-afterimage of Orion and Thuban; Teotihuacan's orthogonal grid perfectly aligns with the setting azimuth of the Pleiades (Swarm Anchor); Stonehenge extends the perceptual path of the Milky Way parallel to its solstitial axis; and Chichen Itza maximizes "Afterimage Salience" ($S_{swarm}$) by synchronizing with the exact zenith passage of the Pleiades. These examples confirm that ancient interpretations of the sky were grounded in shared physiological perception rather than mere symbolic invention. This research consolidates archaeoastronomy, cognitive science, and cultural anthropology into a unified explanatory model, introducing a preliminary mathematical framework to quantitatively reconstruct the "afterimage salience" of ancient skies.