Page 109 - Miracle in the Eye
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powerfully than humans at night. 38
Unlike a human, a bird cannot move its eyes in their sockets. But birds
can quickly move their heads and necks around to expand their perspective.
Without moving its head, an owl has an 80-degree field of vision. But some
species of owl can rotate their heads to up to 360 degrees—a full circle!
The visual field of one human eye is 150 degrees laterally, and only 180
degrees binocularly, or a half circle. 39
As mentioned already, predators such as the owl have very keen night
vision, often six times greater than that of humans. This allows them to per-
form precisely accurate hunting maneuvers.
Larger eyes contain more visual cells, providing better vision. A preda-
tor bird can have more than a million visual cells in each of its eyes.
At night, owls and similar nocturnal birds can see much better than
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