In 2011, Darren Peshek and colleagues from the University of California at Irvine ran a study in which they tampered with the limbal ring: the slightly darker ring that runs around the outside of most people’s irises... He found that both men and women preferred the faces with the dark limbal ring.

For the full story, please visit https://www.psychologytoday.com/blog/attraction-evolved/201711/the-eyes-have-it-limbal-rings-and-attraction.