Thursday Special : Bird’s Eyes

Eyes are the windows of the soul.

Eagle eyes amazing information…

Eagles have unusual eyes. They are very large in proportion to their heads and have extremely large pupils. Eagles’ eyes have a million light-sensitive cells per square mm of retina, five times more that a human’s 200,000. While humans see just three basic colours, eagles see five. These adaptations gives eagles extremely keen eyesight and enable them to spot even well-camouflaged potential prey from a very long distance. In fact the eagles’ vision is among the sharpest of any animal and studies suggest that some eagles can spot an animal the size of a rabbit up to two miles away! (for more information about eagles go here)

Amazing facts about owl’s eyes…

Of all an Owl’s features, perhaps the most striking is its eyes. Large and forward facing, they may account for one to five percent of the Owl’s body weight, depending on species. The forward facing aspect of the eyes that give an Owl its “wise” appearance, also give it a wide range of “binocular” vision (seeing an object with both eyes at the same time). This means the owl can see objects in 3 dimensions (height, width, and depth), and can judge distances in a similar way to humans. The field of view for an owl is about 110 degrees, with about 70 degrees being binocular vision.

An Owl’s eyes are large in order to improve their efficiency, especially under low light conditions. In fact, the eyes are so well developed, that they are not eye balls as such, but elongated tubes. They are held in place by bony structures in the skull called Sclerotic rings. For this reason, an Owl cannot “roll” or move its eyes – that is, it can only look straight ahead!
The Owl more than makes up for this by being able to turn its head up to 270 degrees left or right from the forward facing position, and almost upside down.

Since Owls have extraordinary night vision, it is often thought that they are blind in strong light. This is not true, because their pupils have a wide range of adjustment, allowing the right amount of light to strike the retina. Some species of Owls can actually see better than humans in bright light.

To protect their eyes, Owls are equipped with 3 eyelids. They have a normal upper and lower eyelid, the upper closing when the owl blinks, and the lower closing up when the Owl is asleep. The third eyelid is called a nictitating membrane, and is a thin layer of tissue that closes diagonally across the eye, from the inside to the outside. This cleans and protects the surface of the eye. ( for more information go here)

The bright yellow eye of a Pelican who’s beak can hold more than his belly can…

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Another interesting challenge from Paula at “Lost in Translation”