Which animal has the biggest eyes?
The colossal squid has the biggest eyes of any known animal, about 27 centimeters across, roughly the size of a soccer ball. On land, the ostrich has the largest eyes.
Colossal squid live deep in the Southern Ocean around Antarctica, where very little light reaches. Their huge eyes may help them spot the faint glow made by sperm whales disturbing tiny light-producing creatures, giving them early warning of their main predator. The giant squid also has enormous eyes, similar in size.
On land, the ostrich has the largest eyes of any animal, about 5 centimeters across, each larger than its brain. Large eyes help ostriches spot predators from far away on open plains. Among mammals, horses have some of the largest eyes.
Big eyes for their size
Relative to body size, tarsiers, small primates from Southeast Asia, have some of the largest eyes. Each eye is about as big as its brain. Tarsiers cannot move their eyes in their sockets, so like owls, they turn their heads instead.
Did You Know?
In 2025, a juvenile colossal squid was filmed alive in its deep-sea habitat for the first time.