Sorry, I was practicing the Gawker headline writing style. Anyway, a new study suggests that the larger eyes of the Neanderthals resulted in more of their brain being used to be able to see at night while Homo Sapiens used their brain for higher level processing.

While the Neanderthals were using their brain to process visual information so they could see better during long dark European nights, our ancestors were making better clothes and building larger social networks that helped them survive the ice age.

Read more here and here.