Elegant and expressive, blue-eyed dogs have some of the most unforgettable furry faces around. Scientists have thrown dog-lovers a bone: clues as to what causes this eye-catching trait.

While only 1 in 5 Caucasian adults have blue eyes in the United States, most are born blue-eyed. Their irises change from blue to hazel or brown during infancy. Why? "It has to do with the amount ...

There, at the corner of your yard, where the woods creep up and night obscures the seeming safety of suburbia—a pair of glowing eyes hovers … watching … waiting ...

says this is possible because everybody has blue eyes already. You just can’t see them. “Anyone who has brown eyes has blue eyes underneath,” he says, “and it’s covered by a thin layer ...