Finding one of the most elusive animals on the planet takes patience, determination and a keen eye. When biologists finally spot one, this is what stares back at them.
The eye of the largest invertebrate on the planet measures up to 10 inches in diameter, about as large as a dinner plate. Given the size of these animals — the largest of which ever found was 59 feet in length and weighed nearly a ton — it's no wonder the giant squid has the biggest eye in the animal kingdom.
Despite the many differences in the anatomy of humans and giant squid, the eye is structured much the same, with single lenses, pupils, irises and retinas.
Since the giant squid lives in a deep-sea environment, its massive eyes help the animal to detect objects through the shadowy depths.
Although giant squid specimens have been found worldwide, little is known about the species, including details about the animal's behavior and its range.