Page 111 - Miracle in the Eye

HARUN YAHYA
flight, that split-second may be critical.
This is why birds have a third eyelid—a transparent layer that blinks
and cleans—without their having to close their outer eyelids. This lid
sweeps sideways across the eyeball, starting from the side nearest the beak.
For birds that dive underwater, it also acts as goggles, protecting the eye
from harm. In a sense, birds have been equipped with goggles and aviator
glasses from birth.
Although nocturnal birds cannot see color, some smaller birds feed on
seeds and insects, and therefore do need to discern colors. The eyes of these
smaller birds are placed on either side of the head, which lets them see a
wide area with minimal movement of the head and neck.
The umbrella birds, also known as black herons, encounter a number of
difficulties when they hunt in water. As is well-known, most light reflects off
the water—which has a negative effect on the bird's ability to see objects
under the water's surface. The black heron solves this problem by spreading
its wings. This cuts the sunlight and any reflections, allowing it to see more
clearly and hunt for fish underwater.
If the black heron didn't use its wings this way, it would be unable to see
its food and therefore starve. But seabirds are somehow born knowing the
laws of optics, and take the needed precautions accordingly. Could it be that
all the seabirds came together to find a practical solution to their problem?
Or did they take a mass physics lesson and arrive at a solution by experi-
menting?

Hunting Eyes
Eagles fly at an altitude of thousands of meters, in a manner similar to
modern war planes, yet are able to comb the landscape below in staggering
detail. The eagle can detect even the slightest of movements or color changes
while in flight. It owes this ability to a very special eye structure.
In humans, the portion of the retina with the most acute vision is the
fovea centralis, which has the highest concentration of cone cells. Eagles
have two foveae, giving them an incredibly sharp sense of sight. Humans
have only one fovea in each eye—for binocular, or forward vision. When we

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