In the cold depths of Arctic waters, Greenland sharks have spent centuries seeing what scientists assumed they could not — and a preserved eye delivered to a California laboratory has begun to unravel why. Researchers at UC Irvine discovered that these 400-year-old vertebrates maintain healthy retinal tissue and active vision proteins without the degeneration that time typically demands, suggesting that nature has already solved problems human medicine is only beginning to ask. The mechanisms behind this biological patience — likely rooted in specialized DNA repair — may one day offer a path t