Four Eyed Fish

The anablep, a South American fish can give us some ideas. This fish is also called the “four-eyed fish” because it swims at the surface of the water, with half its eyes out of the water. This allows the fish to see predators from above, and food below. That’s because this fish has a bifocal built into its eye. Thus, it has a “multifocal lens” inside the eye.