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For other uses, see Eagle Eye (disambiguation).
Eye of a Golden Eagle
The eagle eye is among the strongest in the animal kingdom, with an eyesight estimated at 4 to 8 times stronger than that of the average human. An eagle is said to be able to spot a rabbit 2 miles (3.2 km) away. Although an eagle may only weigh 10 pounds (4.5 kg), its eyes are roughly the same size as those of a human. As the eagle descends from the sky to attack its prey, the muscles in the eyes continuously adjust the curvature of the eyeballs to maintain sharp focus and accurate perception throughout the approach and attack. In addition to eagles, birds such as hawks, falcons, and robins have extraordinary vision which enable them to gather their prey easily. Their eyes are stated to be larger in size than their brain, by weight. Colour vision with resolution and clarity are the most prominent features of eagles' eyes, hence sharp-sighted people are sometimes referred to as "eagle-eyed.” Eagles can identify five distinctly-coloured squirrels and locate their prey even if hidden. Contents
Eagle weight varies: a small eagle could weigh 0.7 kilograms (1.5 lb), while a larger one weighs 6.5 kilograms (14 lb); an eagle of about 10 kilograms (22 lb) weight could have eyes as big as that of a human being who weighs 200 pounds (91 kg). Although the size of the eagle eye is about the same as of a human being, the back side shape of the eagle eye is flatter. An eagle's retina allows for a higher Nyquist limit. Its retina is more pronounced with rod cells and cone cells. In the eagle, the retina's fovea has one million cells per mm as compared to 200,000 per mm in humans. Eagles have a second fovea and three eyelids (two of which are visible). The second fovea in eagles gives them better and sharper vision while the long, narrow...
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