Ancient Sharks Keep Eyes Young

great white shark swimming in sunlit blue water — Photo: Fiona Ayerst / Shutterstock

Scientists found that Greenland sharks keep working retinas into extreme old age, hinting at DNA repair tricks that protect vision for centuries.

Story Snapshot

Peer-reviewed study shows preserved, working retinas in adult Greenland sharks adapted to deep, dim seas.
Researchers tie retinal health to DNA repair genes ERCC1 and ERCC4, which may guard eye tissue.
Tests on sharks aged about 100–134 years showed intact rods and blue-light tuning near 458 nanometers.
Findings could guide human eye research, though the exact mechanism is not yet proven causal.

Researchers document preserved vision in Earth’s longest-lived vertebrate

Nature Communications published new work on the Greenland shark’s eyes. The team reported a preserved and functional visual system in adults. The visual system appears tuned for extreme low light in deep, cold waters. The study combined genetic reads, tissue slides, and functional tests to support the finding. This matters because the species can live close to four centuries, yet its retina shows little of the wear seen in other animals as they age.

Reporters summarizing the paper said the group examined eyes from 10 deceased sharks between roughly 100 and 134 years old. The tissue held healthy rod cells, which help detect light in the dark. The pigment rhodopsin appeared tuned to blue wavelengths near 458 nanometers. That shift fits the color of light that reaches deep water, where these sharks spend much of their lives. This supports the claim that the retina remains useful even late in life.

DNA repair pathways linked to retinal preservation

The authors linked retinal health to genes that fix DNA damage. They highlighted retention of the ercc1 gene and higher expression of ercc4, also known as xpf, compared with shorter-lived sharks. These genes form a repair complex that helps keep cells stable. The study said transcript data suggest this pathway helps protect the retina over centuries. The wording is careful and points to a likely role, not final proof of cause.

Why this matters goes beyond marine biology. If eye cells in a very old animal can avoid breakdown, scientists may learn how to slow damage in human eyes. Many people fear losing sight due to age or disease. A natural model that keeps retinal cells working could offer clues for new drugs or gene targets. Those targets might support DNA repair or reduce harm from daily light stress. The paper sets a direction for follow-up studies.

What the tests did—and did not—show

The team did not track the same shark across centuries. Instead, they used anatomy, gene reads, and light-response signs from tissue. The findings back working rods and intact structure in very old adults. The sample set was limited to about a dozen eyes near 100 to 134 years, based on reports, not the maximum possible age. That still gives strong evidence for preserved vision, while leaving room for more tests in older classes.

Past work has shown Greenland sharks can reach ages near 400 years using eye-lens radiocarbon dating. That method is standard for long-lived fish and sharks. It uses bomb-era carbon traces to estimate age. The new paper builds on that base and focuses on the retina. It shows that vision-linked parts of the eye—and the genes that protect them—do not fail fast, even after a century of life.

How this connects to public concerns about science and health

Americans across the spectrum worry that leaders promise cures but deliver little. This study is not a cure. It is a clear result that points to how nature solves a hard problem. A shark keeps its retina working in the dark for a very long time. That is a real clue, not hype. If labs can copy the shark’s repair tricks safely, elders here could keep more of their sight longer. That is a practical hope grounded in data, not politics.

What comes next for verification and impact

Independent labs can test more eyes, including the oldest sharks found. Teams can measure eye tissue responses directly and probe how ERCC1 and ERCC4 act in cells. Researchers can compare with shorter-lived shark relatives to see which features matter most. These steps would confirm how much the repair pathway drives retinal health. Careful follow-up will tell us how far these shark lessons can go toward human eye therapies.