Greenland sharks can live 400 years without losing their vision: Scientists once thought they were blind, now they know why

Greenland sharks can live for more than 400 years, but scientists once believed the deep-sea giants were functionally blind because of their cloudy eyes and parasites. A new study has challenged that assumption, finding healthy retinal tissue and visual proteins adapted to the dim Arctic depths. Researchers say the findings could offer clues into how the eyes resist age-related damage and potentially help scientists better understand human vision loss.