In the lightless depths of the Arctic, a creature that has outlived empires is quietly rewriting what science thought it knew about aging and sight. Researchers at UC Irvine, studying the eyes of Greenland sharks — Earth's longest-living vertebrates, some four centuries old — have found retinas that refuse to deteriorate, sustained by DNA repair mechanisms that defy every assumption about the biological cost of time. The discovery, published in Nature Communications, opens a door long thought sealed: that the secrets to preserving human vision into old age may lie not in a laboratory, but in t