Researchers knew the mantis shrimp had some tricked-out peepers—its visual world consists of 11 to 12 basic colors (compared with three for humans) as well as infrared and ultraviolet light. But there's even more to this prawn's vision than meets the eye: A new study in the online journal PLoS ONE finds that the colorful mantis shrimp has something called "optimal polarization vision." The effects of polarization—the spatial orientation of light's electric field—are familiar to owners of high-end sunglasses, which cut glare by blocking light polarized along a single axis. But polarization comes in a range of values from straight to circular (twisted left or right). By combining input from its eyes' six different polarization channels, the mantis shrimp can distinguish the whole polarization spectrum. Researchers say the beasties might use their keen vision in flirting (their bodies reflect polarized light) or to hunt otherwise-transparent prey that contain light-polarizing sugars.