How big are ostrich eyes?
An ostrich's eyes are bigger than its whole brain.
Each eye is about 50 millimeters (2 inches) wide, about the size of a billiard ball. The eyes take up most of the space inside the skull. That leaves the brain much smaller by weight and size.
Nerd's Section
The common ostrich (Struthio camelus) has the largest eyes of any land animal. Each eye measures about 50 millimeters across, which is about 2 inches. A human eye is only about 24 millimeters wide, so an ostrich eye is more than twice as wide.An adult ostrich brain weighs about 40 grams (1.4 ounces). One ostrich eye can weigh around 60 grams (2.1 ounces). That makes each eye heavier than the brain and means the eyes take up most of the room in the skull.The eyes sit on the sides of the head and give ostriches a very wide field of view to spot danger. Dr. Graham Martin at the University of Birmingham has studied how they use vision to watch for predators. Ostriches can weigh up to 150 kilograms (330 pounds) and run about 70 kilometers per hour (43 mph), so their bodies are built for speed rather than a large brain. Their eyelids, thick lashes, and a clear third eyelid help keep dust out in dry places like the African Sahel.
Verified Fact
FP-0000899 · Feb 26, 2026