Overview
- A Nature Communications paper reports structurally preserved retinas in Greenland sharks more than 100 years old with evidence consistent with retained visual function.
- Researchers examined eyes from 10 sharks estimated at 100–134 years and found rod-only retinas, a reflective tapetum lucidum, and peak sensitivity to blue wavelengths common in deep water.
- Video observations documented eyeball movements toward light, supporting behavioral use of vision even when corneal copepod parasites obscure the eye surface.
- Gene expression results highlight DNA repair genes ERCC1 and ERCC4 as candidates for mechanisms that help maintain retinal health over long lifespans.
- The authors flag limits including small sample size, challenges in precise age estimation, and no tests of vision in natural settings, while noting potential relevance to human age-related vision research.