Eye-Opening Research

Dorota Skowronska-Krawczyk sits in her office, eyes fixed on the computer monitor in front of her.

“You see it move its eye,” says the UC Irvine associate professor of physiology and biophysics, pointing to an image of a Greenland shark slowly drifting through the murky Arctic Ocean. “The shark is tracking the light – it’s fascinating.”

The video shows the longest-living vertebrate in the world – long, thick, grey body; small head; and short, rounded snout – with opaque eyes that appear lifeless, except for the parasite latched to one of its eyeballs. Scientists have long suspected the large species to be functionally blind, given the frequent presence of the parasite and its exceptionally dim and obstructed visual environment.

Now, new research from Skowronska-Krawczyk on Greenland shark vision – co-authored by University of Basel, Switzerland researchers Walter Salzburger and Lily G. Fogg, who worked on the evolutionary aspect of the study – is challenging what we know about aging, vision and longevity.

Published in Nature Communications, her findings suggest that a DNA repair mechanism enables these sharks – some of which live for 400 years – to maintain their vision over centuries, with no signs of retinal degeneration, and that they are well-adapted to extreme low-light conditions.

Skowronska-Krawczyk, who gleans insights into the molecular mechanisms of aging by studying processes that control age-related eye diseases, attributes her interest in the visual system of the Greenland shark to a 2016 research paper by John Fleng Steffensen published in the journal Science.

“One of my takeaway conclusions from the Science paper was that many Greenland sharks have parasites attached to their eyes – which could impair their vision,” she says. “Evolutionarily speaking, you don’t keep the organ that you don’t need. After watching many videos, I realized this animal is moving its eyeball toward the light.”

This left Skowronska-Krawczyk wanting to learn more.

Read the full feature story on Skowronska-Krawczyk's research in UC Irvine News.