This is entirely too freaking cool. It’s fairly well accepted that one of the reasons birds are able to accurately migrate repeatedly is due to their ability to sens magnetic fields. According to this research, for species like the European Robin, this manifests as an augmentation to their vision, but only over the right eye. It appears as banding, indicating the Earth’s magnetic field.
The ability is tied directly to their right eye, and requires both large amounts of light, and clear vision to activate. When vision through the right eye was obscured, the Robins would fly randomly, but if the left eye was blocked, they would fly directly north.
Some other bird types detect magnetic fields in other ways, through small crystals of magnetite in their beak.
Man, I wonder what it would take to hack this into the human body…