Mark Ruffalo already has Hulked out in Avengers, but it took us staring at new Avengers: Age of Ultron stills to notice that his green guy doesn't have green eyes. Look, they're hazel ...

while only 8 to 10% of people worldwide have blue eyes, 5% have hazel eyes and about 2% of all people have green eyes. But brown eyes aren’t quite as dominant in the United States. According to ...

most are born blue-eyed. Their irises change from blue to hazel or brown during infancy. Why? "It has to do with the amount of melanin they're born with and how that melanin increases after birth ...