The Man With Uncrossed Eyes

"GB" is a 28 year old man with a curious condition: his optic nerves are in the wrong place. Most people have an optic chiasm, a crossroads where half of the signals from each eye cross over the midline, in such a way that each half of the brain gets information from one side of space. GB, however, was born with achiasma - the absence of this crossover. It's an extremely rare disorder in humans, although it's more common in some breeds of animals, such as Belgian sheepdogs. Here's GB and a normal brain for comparison: