How is a manatee's eye adapted to see underwater?

A manatee's eye is adapted for underwater vision by having a flattened lens that helps focus light more effectively in water, which has a different refractive index than air. Additionally, their eyes possess a nictitating membrane, or a protective third eyelid, that allows them to see clearly while swimming or when submerged. This adaptation enhances their ability to navigate and find food in their aquatic environment.