All blue-eyed people in the world can trace their lineage back to one common ancestor who lived between 6,000 and 10,000 years ago, according to researchers from the University of Copenhagen.

This ancestor carried a gene called HERC2, which is responsible for blue eyes as it shuts off the OCA2 gene that determines brown pigment in the eyes.

This mutation has been passed down through generations, making every blue-eyed person a distant relative.

So, if you have blue eyes, you share a common ancestor with millions of people worldwide.

However, since this ancestor lived thousands of years ago, you don’t have to feel obliged to send Christmas cards to eight to 10 percent of the world’s population!