The bald eagle is among the most majestic raptors in North America. It’s because of its noble features, great strength, and amazing agility that it was chosen as the national bird of the United States in 1792. Among the eagle’s many interesting characteristics and abilities, is their incredible vision. In fact, an eagle’s eyesight is among the best in the entire animal kingdom. It’s for good reason that the term “eagle eyes” came to be.
Bald eagles typically weigh around 8 to 14 pounds and on average stand about 32 inches tall. While eagles and humans are obviously very different in height and weight, the size of our eyeballs is almost the exact same. Even more interesting is that an eagle’s eye weighs more than its brain! However, while the eagle has such large eyes, they can’t move them around easily in their eye sockets as we humans can, which is why they move their entire heads around while surveying an area or zooming in on a potential meal.
While people and bald eagles have eyes that are about the same size, that’s where the similarity ends. Eagles have a 340 degree field of vision compared to the 180 degrees of we humans. An eagle eye has two focal points which allow them to see straight ahead as well as off to the side at the same time, and they can also use their eyes independently of each other to focus in on separate subjects.
The retina of an eagle’s eye has very sensitive light-detecting cells and their astounding depth of vision allows them to focus in like a strong telephoto lens. Bald eagles are believed to be able to spot a rabbit or similar sized animals up to three miles away and can see an ant crawling on the ground from a vantage point as tall as a ten-story building.
Along with being able to see four to five times farther than we humans, eagles see colors much more vividly than people and other animals, and they can also see ultraviolet light, which helps them when tracking elusive prey items. Their vision is so incredibly sharp that they can easily spot highly camouflaged animals such as a snowshoe hare or ermine during the wintertime, as well as spotting fish under the surface of the water.
Adult bald eagles have yellow eyes while the younger, juvenile eagles have brown eyes that gradually lighten as they mature. Eagles of any age also have eyelids that they close while sleeping as well as a translucent membrane that moves across their eyes every few seconds to keep them clean.
Having super-power vision does come at a cost, however. Scientists believe that because eagles dedicate so much of their brainpower to their vision, that they have a much less developed sense of smell and taste as a result when compared to other animals.
So that’s an overview of the amazing eyesight of the bald eagle. Check out the video below to see more.