Discovered in the deep: the squid that sees both ways at once

The left eye of the cockeye squid is much bigger than the right, helping it spot prey or enemies above. Photograph: Courtesy of MBARI

Cockeye squid face a conundrum. Living hundreds of metres underwater, they float in between two worlds. Above them is the surface ocean, where a dim blue fraction of sunlight filters down. Below them is the deep sea, sunless and black. Which way to look?

Their mismatched eyes solve the problem – by letting them gaze into both worlds at once.