A tiny ocean worm just revealed a big secret about how eyes evolve

Scientists found that adult bristleworm eyes grow continuously thanks to a rim of neural stem cells similar to those in vertebrate eyes. This growth is surprisingly regulated by environmental light via a vertebrate-like c-opsin. The discovery reveals deep evolutionary parallels between distant species and raises questions about how light shapes nervous systems beyond vision. It hints at hidden complexity in creatures long assumed to be simple.

source https://www.sciencedaily.com/releases/2025/12/251202052211.htm