Lights in the eyes for better disguise. Duke Today, June 11, 2020. This hatchetfish hides from predators swimming in the shadowy depths below using a clever disguise. Glowing spots on its belly make it nearly invisible against the sunlit waters above. But the fish’s eyes point upward — How does it adjust its underside lights to blend in with the faint light filtering down from above if it can’t see its belly?