Eagle eye

The golden eagle is well known for its sharp sight.
In conformity with other predator birds its eyes gives a clear and detailed picture of the surroundings. One of the reasons is the round shape and the size of the eyes.
For a golden eagle it is possible to discover a small prey, like a hare, at a distance of 1,5 km. That´s because a part of the retina works as a telephoto lens in a camera, on condition that the daylight is sufficient.

 

The eagle eye is nearly as big as a human beings. Therefore there isn´t room for muscles to move the eyes in the eagles skull and it has to turn the whole head to look around.
In one of the pictures you can see an eagle who has almost turned its head upside down to take a look at the raven above in the pine tree.

 

The almost transparent membrane keeps the eye damp.
An eagle blink is very quick and almost impossible for us to comprehend.