Nearly 80 percent of people worldwide have some shade of brown, ranging from light caramel to nearly black. Brown eyes ... natural UV protection. Hazel eyes are a mix of brown, gold, green ...
As for Hazel's favorite print? "Mermaid," the Busby daughter tells PEOPLE. Hazel was born with an eye condition called congenital nystagmus, which is "an involuntary eye flutter," Adam explained.