Shark's Eyes Defy Expectations: Can See for Centuries

Topic: Biology

Scientists studied Greenland sharks and found that they can see despite living in very dark waters. The sharks' eyes have a special mechanism to repair DNA, which helps them preserve their vision.

Dorota Skowronska-Krawczyk, an associate professor at the University of California, Irvine, was studying Greenland sharks on her computer screen. She pointed out how the shark moves its eye towards light, saying it's fascinating. Greenland sharks are known to live up to 400 years, making them the longest-living vertebrates in science.

The scientists suspected that the sharks might be functionally blind due to parasites attached to their eyes and living in extremely dark waters. However, new research led by Skowronska-Krawczyk suggests a different picture. The study found that Greenland sharks have a DNA repair mechanism that helps them preserve their vision for centuries without showing signs of retinal degeneration.

The researchers studied the molecular processes involved in age-related eye diseases to better understand how aging affects vision. They examined the eyes of Greenland sharks caught between 2020 and 2024 near the University of Copenhagen's Arctic Station on Disko Island, Greenland. The team found no evidence of cell death in the retina and discovered that a protein essential for vision in dim light remained active in the shark retina.

This adaptation helps the sharks see in the faint light available in their Arctic habitat. Skowronska-Krawczyk's interest in Greenland sharks began after reading a 2016 research paper by John Fleng Steffensen published in the journal Science.

Why It Matters

Understanding how Greenland sharks can preserve their vision for centuries can help us learn more about aging and longevity in humans. This research can also lead to new discoveries about eye diseases and treatments.

Key Facts

• Greenland sharks can live up to 400 years, making them the longest-living vertebrates in science.
• The sharks have a special DNA repair mechanism that helps them preserve their vision for centuries.
• The researchers found no evidence of cell death in the retina and discovered that a protein essential for vision in dim light remained active in the shark retina.
• Greenland sharks live in extremely dark waters, but their eyes are adapted to detect blue light, which helps them see in faint light.
• The study was published in Nature Communications on January 5, 2026.

Key Terms

DNA repair mechanism

A process that helps fix damaged DNA and preserve cells' function.

Rhodopsin

A protein essential for vision in dim light that remains active in the shark retina.

Vertebrates

Animals with a backbone, including humans, animals, and fish.

Implications

Understanding how Greenland sharks can preserve their vision for centuries can help us learn more about aging and longevity in humans. This research can also lead to new discoveries about eye diseases and treatments.