Deep-Sea Predator Outsmarts Blindness

Sharks swimming above a coral reef — Photo: Lewis Burnett / Shutterstock

A new peer-reviewed study finds Greenland sharks keep working retinas into extreme old age, hinting at natural tools to fight vision loss in people.

Story Highlights

Nature Communications paper reports intact, light-sensitive retinas in century-old Greenland sharks.
Researchers link retinal preservation to DNA repair genes ERCC1 and ERCC4 (also called XPF).
Reporting says samples came from 10 sharks aged 100–134 years, not the oldest possible.
Blue-light tuning fits deep, dim Arctic waters where these sharks spend their lives.

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

Scientists reported that adult Greenland sharks show a preserved and functional visual system, adapted to very low light. The peer-reviewed paper combined genome, gene-expression, and eye tissue studies. The team found retinal cells and visual machinery that still work in older sharks. The authors write that their data support intact vision in adults and strong adaptation to dim light, such as deep Arctic waters where the species hunts and scavenges.

Coverage of the work explained that the retina contains rod cells tuned to blue light around the wavelengths common in deep water. That tuning helps the sharks detect movement and contrast in near darkness. Media summaries described the retina’s sensitivity and said the tissue supports dim-light vision rather than sharp daytime sight. This matches the shark’s slow life in cold, deep seas where blue light penetrates best and color vision would add little.

DNA repair pathways may protect the retina for centuries

The study connected retinal health to DNA repair. The team reported retention of the ercc1 gene in long-lived sharks and higher expression of ercc4, also known as xpf, in Greenland sharks versus other species. These genes work together in a repair complex that fixes DNA damage. The authors argue that keeping these genes active may help prevent retinal breakdown, sustaining vision far into old age, though they frame this as a suggested mechanism, not proven cause.

The paper’s summary highlighted no obvious retinal degeneration in exceptionally old individuals. That result, paired with the DNA repair findings, outlines a possible way the species keeps its eyes working for so long. The work points to a link between healthy aging and stable vision that could guide future eye research. Scientists see a path to test whether boosting similar repair activity might protect human retinas from age-related decline.

Sample limits and why this still matters

Reporting noted that the team examined eyes from 10 deceased sharks estimated at 100 to 134 years old. These are very old animals by human standards, but younger than the oldest Greenland sharks, which can near four centuries. That means the data show preserved vision past a century, with the “centuries-long” framing grounded in the species’ known lifespan, not direct tests on a 300- or 400-year-old eye.

The central claim still stands on firm ground. The study looked directly at retinas, not only at lore about cloudy corneas or parasites that can cover the eye’s surface. By pairing tissue slides, gene activity, and genome features, the authors built a focused case for preserved dim-light vision in very old animals. That matters for people worried about macular degeneration and other eye diseases. Nature may already run the playbook for keeping retinal cells healthy.

What this teaches about science, aging, and trust

This result shows how careful lab work can cut through myths. For years, many thought Greenland sharks were nearly blind because their corneas look damaged. The new evidence shows a different story: the retina still works in low light, even after a century. This is a sober finding, not hype. It does not promise super vision. It shows function that fits the shark’s world and hints at repair systems we can study with care and transparency.

Where research goes next

Scientists can now test retinal responses across more age groups, including the very oldest sharks they can sample. Independent labs can repeat the gene and tissue work to confirm the results. Teams can also study how the ERCC1-ERCC4 repair complex acts in shark retinal cells. Step by step, this could guide safer ways to protect human vision. That is slow, public science that earns trust and serves people across the political spectrum.