Research overview: the tapetum lucidum and reflective enhancement of night vision

The eerie eyeshine of cats comes from the tapetum lucidum, a reflective layer behind the retina, and this overview reviews how it boosts vision in dim light. By bouncing light that has passed through the retina back across the photoreceptors, the tapetum gives the cells a second chance to capture photons, increasing sensitivity at the cost of some image sharpness. The feline tapetum is built from layered crystalline structures that reflect efficiently. Researchers study it through ocular anatomy, optical measurement of reflectance, and comparison across nocturnal and diurnal species. Why it matters: the tapetum is a key reason cats see so well at night, central to their crepuscular and nocturnal hunting, and it exemplifies an optical adaptation found across many night-active animals, with the cat as one of its best-known and best-studied examples.