Animals as varied as salmon, honeybees, and migratory birds have a magnetic sense that sees the Earth's magnetic field and allows them to distinguish North, South, East, and West. In migratory birds the magnetic sense is apparently based on a protein called cryptochrome that acts in the retina, the light-sensitive part of the eyes. In their sensing function cryptochromes rely on light-dependent reactions which depend on the protein's orientation in the geomagnetic field. The product of the reaction in cryptochrome is said to affect the sensitivity of light receptors in the retina of a bird's eye such that a bird literally "sees" the geomagnetic field. However, cryptochrome in the eye most likely is not perfectly aligned with the retina, even if bound to ordered membrane structures found in the outer segments of the eye's light receptors. In a recent report, researchers have shown that birds' vision-based compass is surprisingly insensitive to cryptochrome disorder. The researchers suggest a cloud-like pattern in the visual field that points a bird to the correct orientation. More on our cryptochrome web site.