How The World’s Oldest Vertebrate Maintains Its Eyes For Centuries

Researchers found Greenland sharks have retinas made almost entirely of densely packed rods tuned to blue light.

The sharks show strong rod-gene expression and loss of many cone genes, matching a dim, blue ocean habitat.

Retinal cells show elevated DNA repair gene activity, which may help preserve vision across centuries.

Eye parasites are common but do not fully block light, so the sharks are not blind despite appearances.