Greenland shark eyes show remarkable resilience across centuries of life
Greenland sharks, which can live up to 400 years, appear to maintain healthy retinal tissue despite their extreme longevity. Researchers found active proteins specialized for blue-light vision in the dark Arctic waters, along with DNA repair mechanisms that may protect their eyes. These findings could offer insights into preserving human vision with age.
The study, published in Nature Communications, examined eyes from sharks caught between 2020 and 2024 near Disko Island, Greenland, with collaboration from the University of Copenhagen, Indiana University South Bend, and the Virginia Institute of Marine Science. Researchers identified active proteins specialized for blue-light vision, an adaptation suited to the dim Arctic depths where longer wavelengths barely penetrate.
The findings directly challenge the long-held assumption that Greenland sharks are functionally blind due to eye parasites and murky waters. Skowronska-Krawczyk's observation of sharks tracking light in video footage prompted the investigation. The presence of DNA repair mechanisms in retinal tissue suggests these animals maintain eye health across centuries, offering a striking contrast to typical age-related retinal decline in other vertebrates.
This research could reshape how scientists approach age-related vision loss in humans. If the DNA repair mechanisms identified in Greenland sharks can be understood and potentially replicated, it may inform therapeutic strategies for conditions like macular degeneration. Older populations, who disproportionately experience vision decline, could ultimately benefit from treatments inspired by these findings. However, translating insights from a 400-year-old Arctic shark into clinical applications remains a distant prospect requiring substantial further investigation.