Scientists discover Greenland sharks can see for centuries, debunking blindness myth

Greenland sharks entered popular science writing on the strength of one number, 400 years. Some individuals swimming in the North Atlantic today were alive during Isaac Newton's lifetime, born centuries before anyone thought to ask how old a shark could get. That figure alone would be enough to make the species a fixture of "strange but true" science coverage, alongside the immortal jellyfish and the bristlecone pine.What usually got attached to the longevity claim, almost as a footnote, was a second one: that the sharks spent those centuries essentially blind, their eyes clouded and colonised by a permanently attached parasite. The two claims travelled together for years, so often that they came to feel like a single fact rather than two separate findings with very different levels of evidence behind them.How scientists discovered Greenland sharks can live for nearly 400 yearsAccording to the 2016 study published in Science, titled ‘Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)’, radiocarbon dating was conducted on the eye lens nuclei of 28 female Greenland sharks, ranging from 81 to 502 centimetres in length. The lens nucleus...