Sharp-eyed robins can see magnetic fields

Sharp-eyed robins can see magnetic fields: "It has been known for decades that some birds are able to sense the Earth's magnetic field and set their direction as if following a compass heading, which is an extremely useful ability for birds migrating long distances. The ability is believed to be linked to the availability of light and it is thought that specialized molecules in the birds' retinas allow them to literally see the magnetic fields, which appear as patterns of light and shade superimposed over the regular image from light. Now a new study shows that the internal compass also depends on the birds having clear vision in their right eyes."