Researchers at Monterey Bay Aquarium Research Institute solved the half-century mystery of a fish with tubular eyes and a transparent head. The Macropinna microstoma have tubular eyes that are very good at collecting light. However the eyes were believed to be fixed in place, providing only tunnel vision of whatever was above the fishâs head. A new paper shows that these unusual eyes can rotate within a transparent shield that covers the fishâs head. This allows the barrel eye to peer up at potential prey or focus forward to see what it is eating. Deep-sea fish have adapted to their pitch-black environment in a variety of amazing ways.