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Animals With the Biggest Eyes: 11 Record-Breaking Peepers
Eyes as big as dinner plates, eyes bigger than a brain and eyes that heat themselves. Meet the animals with the biggest eyes in the world.
Big eyes usually mean one thing: the animal needs to see in very little light. That’s why the record holders live in the deep sea or come out at night. There are two kinds of record here: the biggest eyes overall, and the biggest eyes compared with body size. Here are the champions of both.
Colossal squid
The biggest eyes ever measured in any animal. The colossal squid has eyes about 11 in (27 cm) across, the size of a dinner plate, with lenses as big as oranges. They probably help it spot the faint glow of sperm whales disturbing glowing plankton as they dive to hunt it.
Giant squid
A close second. The giant squid’s eyes are also around the size of a dinner plate, about 10 in (25 cm) or more across.
Blue whale
The biggest animal ever has eyes about 6 in (15 cm) wide, roughly the size of a grapefruit. That’s big, but tiny compared with its 100-ft body.
Swordfish
A swordfish’s eyes are about the size of a softball. It has a special heater organ that warms its eyes and brain, helping it see clearly when it dives into cold, dark water to hunt.
Bigeye thresher shark
Its huge eyes can be up to about 4 in (10 cm) tall and sit in keyhole-shaped sockets, so the shark can look straight up to spot prey silhouetted above it.
Strange but trueAn ostrich’s eye is bigger than its brain. Each eye is about 2 in (5 cm) across, the largest of any land animal.
Ostrich
The biggest eyes of any land animal, and bigger than its own brain. Big eyes let ostriches spot predators across the open savanna from miles away.
Horse
Of all land mammals, horses have the largest eyes. Set on the sides of the head, they give the horse an almost all-round view, with only small blind spots right in front and behind.
Tarsier
The record holder for eye size compared with body size among mammals. Each eye of a tarsier is about as big as its brain. The eyes can’t move in their sockets, so it turns its head almost all the way round instead.
Vampire squid
Compared with its body, the vampire squid has the largest eyes of any animal. Its body is only about 6 in (15 cm) long, but each eye is about an inch (2.5 cm) across.
Barreleye fish
Not the biggest eyes, but the strangest. The barreleye has tube-shaped green eyes inside a transparent, fluid-filled head, and it can rotate them to look up or forwards.
Owls
Owls’ eyes are so big that they’re shaped like tubes and can’t move at all. To look around, owls swivel their heads up to about 270 degrees.
The rule of the deep sea and the night: if light is rare, grow a bigger bucket to catch it.
Why do some animals have such big eyes?
A bigger eye gathers more light, so it works better in the dark. That’s why many record holders hunt at night or live in the deep sea, where only faint flashes of glowing animals break the darkness. Big eyes also help animals on open plains, such as ostriches and horses, spot danger far away.
Explore more strange senses in The Fish With a Transparent Head and our Superpowers collection.
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