Aging Rewritten: Sharks Keep Vision Alive

Great white shark swimming toward camera — Photo: Digital Storm / Shutterstock

Scientists found that Greenland sharks keep working retinas and dim-light vision well past 100 years of age, hinting at repair tools that protect eyesight for centuries.

Story Highlights

Peer-reviewed study shows preserved, working retinas in adult Greenland sharks adapted to deep, low light.
Researchers tie retinal health to DNA repair genes ercc1 and ercc4, with elevated ercc4 expression.
Sample included 10 sharks aged about 100 to 134 years, showing little retinal degeneration.
Rod cells and blue-light tuning near deep-sea wavelengths support night-like vision.

What the new study actually found in shark eyes

Researchers reported that adult Greenland sharks have a preserved and functional visual system that fits life in very low light. The peer-reviewed paper in Nature Communications combined genetics, RNA reads, and tissue slides from shark retinas. The authors concluded the retina remains intact and able to detect light and motion in deep, dark waters. They used careful lab tests rather than stories or lore about the species to make this call, anchoring the claim in direct eye data.

Scientists examined eyes from a small set of deceased sharks that were estimated to be between about 100 and 134 years old. Within that group, they did not see obvious retinal breakdown. That is striking because in many animals, age wears down the retina. The team also mapped how the eye is built and which vision genes are active, building a case that these very old sharks still have the basic tools needed for low-light sight.

How Greenland sharks may protect eyesight for so long

The team linked retinal preservation to DNA repair pathways that fix damage over time. They highlighted the ERCC1-XPF repair complex as a likely helper in keeping retinal cells healthy. The study found that long-lived sharks, including the Greenland shark, keep the ercc1 gene, and that Greenland sharks show higher ercc4 expression than other sharks. This pattern suggests repair activity could guard the retina against wear and tear across many decades.

Function tests and coverage point to rod-only retinas tuned for dim light, not bright color vision. Reports describe rods that respond to blue light near deep-ocean wavelengths, around the band where sunlight still penetrates. That matches a life spent in cold, dark water, where spotting contrast and movement matters most. The data back a simple idea: these sharks likely see enough to navigate, feed, and survive in near night-like conditions.

Why this matters beyond one remarkable species

Greenland sharks are famous for extreme lifespan, with prior work using eye-lens radiocarbon dating to estimate ages that can approach four centuries. The new paper narrows in on eyes and suggests a path for keeping vision longer. If DNA repair helps these retinas resist aging, that clue could guide future research on human eye disease. The caveat is important: the study suggests a role for repair genes but does not prove direct cause yet.

Media often turns careful lab results into big headlines. Here, the strongest facts sit in the lab slides and gene reads from a modest set of century-old sharks. Claims about vision lasting 300 to 400 years are a step beyond the data and rest on broader age estimates. Still, the core finding stands: very old Greenland sharks keep retinas in working shape, and their repair genes may show us how living systems fight time in the dark.