Would you be surprised to learn that your eyes are like an eagle's eyes in some ways? You and an eagle（鹰）can see colors. And an eagle's eyes and yours are about the same size. But there are a lot more of a special type of cell（细胞） in an eagle's eyes than in your eyes. These cells send information to the eagle's brain. Getting a lot of information helps an eagle see much better than you. In fact, an eagle can spot a fish in the sea from a mile away.
You and an eagle have eyes that make tears. Your eyes make watery tears that clean your eyes. An eagle's eyes for watery tears and oily tears. Eagles dive into the sea to catch fish. The oily tears guard their eyes from the saltwater.
Like you, eagles have eyelids（眼睑）. You have two eyelids, and you close your eyes by lowering the top lid. When eagles close their eyes, their bottom lids raise up. Eagles have a third eyelid that moves across the eye every few seconds. It wipes（消除）dust away from the eye. An eagle can see through this third eyelid. The eyelid guards the bird's eyes when it swoops（抓取） at 100 miles an hour after its prey（捕食）.
