Billions of people globally experience some kind of vision impairment, with many millions living with near or total blindness. With such an astounding number of people functionally lacking our most primary sense for navigating through the world, scientists have eagerly pursued methods to restore human vision. But while other members of the animal kingdom display remarkable methods of vision regeneration, mammals largely lack these restorative powers. For now, humans lack methods for fully regenerating cells that can completely restore our much-needed vision. But scientists are eagerly hunting for clues to unlock this biological secret—whether in far-flung phylums or within our own bodies.