In the lightless depths of the Arctic, a creature that has outlived empires is quietly rewriting what science thought it knew about aging and sight. Researchers at UC Irvine, studying the eyes of Greenland sharks — Earth's longest-living vertebrates, some four centuries old — have found retinas that refuse to deteriorate, sustained by DNA repair mechanisms that defy every assumption about the biological cost of time. The discovery, published in Nature Communications, opens a door long thought sealed: that the secrets to preserving human vision into old age may lie not in a laboratory, but in t
Greenland Sharks' 400-Year Lifespan Reveals Eye-Aging Secrets
The shark is tracking the light—it's fascinating.
Mark
Why did everyone assume these sharks were blind?
Mimi
The parasites on their eyes, the absolute darkness where they live—it seemed logical. You don't evolve an expensive organ if you can't use it. But Skowronska-Krawczyk watched the videos and saw the sharks moving their eyes toward light. That changed everything.
Mark
What does it mean that their retinas show no cell death?
Mimi
It means that whatever is happening inside those eyes is protecting them from the normal wear of time. A human retina deteriorates. A shark retina from two hundred years old looks like it could belong to a young animal. That's not normal. That's a mechanism we don't fully understand yet.
Mark
The rhodopsin tuned for blue light—is that just an adaptation to their environment, or is it part of the longevity story?
Mimi
Both. It's specialized for the light that actually reaches them in the deep Arctic. But it also stayed active and functional. In aging, proteins often break down or stop working. Here, the protein is still doing its job after centuries.
Mark
What happens if you figure this out?
Mimi
You might be able to prevent or slow macular degeneration, glaucoma—diseases that steal vision from millions of people. You might understand something fundamental about how cells protect themselves from time itself.
Mark
Does the shark know it's helping us?
Mimi
No. It's just living its life, moving through the dark, tracking whatever light finds its way down there. But that life—that impossibly long, quiet life—is teaching us something we desperately need to learn.
The Pulse
- For decades, scientists assumed Greenland sharks were functionally blind — their eyes clouded, parasite-ridden, seemingly useless in an abyss where light barely exists.
- A single observation shattered that consensus: researcher Dorota Skowronska-Krawczyk watched the sharks tracking light on video, and the old certainty collapsed.
- When a baseball-sized, two-hundred-year-old shark eye arrived packed in dry ice at UC Irvine, lab analysis revealed no cell death, active rhodopsin, and blue-light sensitivity precisely tuned for Arctic waters.
- The mechanism behind this endurance — a form of DNA repair that preserves retinal health across centuries — is now the urgent focus, with human diseases like macular degeneration and glaucoma squarely in its sights.
- Federal funding uncertainty threatens to dim the research just as it reaches its most promising threshold, leaving the frontier partially lit.
In the lightless depths of the Arctic, a creature that has outlived empires is quietly rewriting what science thought it knew about aging and sight. Researchers at UC Irvine, studying the eyes of Greenland sharks — Earth's longest-living vertebrates, some four centuries old — have found retinas that refuse to deteriorate, sustained by DNA repair mechanisms that defy every assumption about the biological cost of time. The discovery, published in Nature Communications, opens a door long thought sealed: that the secrets to preserving human vision into old age may lie not in a laboratory, but in the ancient, clouded eyes of a deep-sea predator.
Dorota Skowronska-Krawczyk was watching footage of a Greenland shark moving through near-solid Arctic darkness when she noticed something that shouldn't have been possible: the animal's eye was tracking light. For decades, the scientific consensus held that these sharks — the longest-living vertebrates on Earth, some surviving four centuries — were effectively blind. Their eyes appear clouded, parasites cling directly to the eyeballs, and the environment offers almost nothing to see. The assumption seemed reasonable. It was wrong.
Between 2020 and 2024, researchers collected Greenland shark eyes near Disko Island, Greenland, and shipped them to UC Irvine for analysis. When a baseball-sized eyeball from a two-hundred-year-old shark arrived packed in dry ice, Ph.D. student Emily Tom carefully thawed the tissue and began examining the retina. What she found overturned the prevailing assumption entirely: no signs of cell death, and rhodopsin — the protein essential for low-light vision — still active and precisely tuned to detect the faint blue wavelengths that penetrate Arctic water. The eye had not decayed. It had endured.
Published in Nature Communications with collaborators from the University of Basel and the University of Copenhagen, the research points to a DNA repair mechanism that allows Greenland sharks to preserve their retinas across centuries — a feat that would be biologically catastrophic for any human eye over a fraction of that span. For Skowronska-Krawczyk, whose work centers on how aging damages vision, the discovery reframes the question: not merely how these animals live so long, but how their tissues remain functional when everything known about aging insists they should fail.
The implications for human medicine are significant. Understanding this protective mechanism could open new pathways for treating macular degeneration, glaucoma, and other age-related vision diseases. Skowronska-Krawczyk speaks of being at a frontier, of new rules waiting to be discovered — even as federal funding uncertainty casts a shadow over the work. The shark on her screen, paused mid-glide through the dark, carries within its ancient eyes a possibility: that learning to see as we age may begin with understanding a creature that has been doing exactly that for four hundred years.
Dorota Skowronska-Krawczyk sits at her desk at UC Irvine, watching footage of a Greenland shark move through Arctic waters so dark it seems almost solid. She points to the screen. There—the shark's eye shifts. It's tracking light. It's alive, in ways that contradict everything scientists thought they knew.
Greenland sharks are the longest-living vertebrates on Earth. Some have survived four centuries. They are built for the abyss: thick gray bodies, small heads, rounded snouts. Their eyes look clouded, almost dead. Parasites cling directly to the eyeballs. For decades, researchers assumed these animals were functionally blind—that in an environment so dark, so hostile, vision would be the first thing to go. Why keep an organ you cannot use?
But Skowronska-Krawczyk noticed something else. After watching hours of video, she saw the sharks moving their eyes toward light sources. The assumption cracked. She decided to look closer.
Between 2020 and 2024, researchers caught Greenland sharks near Disko Island in Greenland using scientific long lines. They dissected the eyes and preserved them in fixative solution. When one arrived at Skowronska-Krawczyk's lab—a baseball-sized eyeball from a shark that had lived two hundred years, packed on dry ice—Emily Tom, a 28-year-old Ph.D. student, opened the package and laughed. She was used to working with mouse eyes the size of papaya seeds. The lab smelled like a fish market as she carefully thawed the tissue, watching the temperature so it would not degrade.
What Tom found was unexpected. The retina showed no signs of cell death. The protein rhodopsin, essential for vision in dim light, remained active. It was tuned to detect blue light—a precise adaptation for the faint wavelengths that penetrate Arctic waters. The sharks' eyes had not deteriorated. They had endured. The research, published in Nature Communications and conducted with collaborators from the University of Basel and the University of Copenhagen, suggests that a DNA repair mechanism allows these animals to preserve their vision across centuries without the retinal degeneration that would devastate a human eye over a fraction of that time.
The implications reach beyond sharks. Skowronska-Krawczyk studies how aging damages vision. She sees in these ancient eyes a possibility: that understanding how Greenland sharks keep their retinas healthy might point toward new ways to prevent macular degeneration, glaucoma, and other age-related vision loss in humans. The question becomes not just how these sharks live so long, but how their tissues—their eyes, their cells—remain functional when everything we know about aging says they should fail.
Skowronska-Krawczyk remains optimistic, though federal funding uncertainty clouds the future of this work. She speaks of being at the frontier, of discovering new mechanisms and rules, of sharing that discovery with students. The shark on her screen, paused mid-glide through the dark, holds secrets that might one day help us see better as we age.
Notable Quotes
You see it move its eye. The shark is tracking the light—it's fascinating.— Dorota Skowronska-Krawczyk, UC Irvine associate professor
We can learn so much about vision and longevity from long-lived species like the Greenland shark.— Emily Tom, UC Irvine Ph.D. student
Want the full story?
Read the original at Mirage News ↗
Education