Page 229 - The Evolution Deceit

The Fact of Cre a tion 227

Left: A cut tle fish that makes it self look like the sandy sur face. Right: The bright yel low
col our the same fish turns in case of dan ger, such as when it is seen by a div er.

This system operates so effectively that the cuttlefish can also create a
complex zebra-like striping. 195

Different Vision Systems
For many sea-dwelling animals, seeing is extremely important for hunt-
ing and defence. Accordingly, most of the sea-dwelling animals are
equipped with eyes perfectly created for underwater.
Under water, the ability to see becomes more and more limited with
depth, especially after 30 meters. Organisms living at this depth, however,
have eyes created according to the given conditions.
Sea-dwelling animals, unlike land-dwelling animals, have spherical
lenses in perfect accordance with the needs of the density of the water they
inhabit. Compared to the wide elliptical eyes of land-dwelling animals, this
spherical structure is more serviceable for sight under water; it is adjusted to
see objects in close-up. When an object at a greater distance is focused upon,
the whole lens system is pulled backwards by the help of a special muscle
mechanism within the eye.
One other reason why the eyes of the fish are spherical is the refraction
of light in water. Because the eye is filled with a liquid having almost the
same density as water, no refraction occurs while an image formed outside
is reflected on the eye. Consequently, the eye lens fully focuses the image of
the outside object on the retina. The fish, unlike human beings, sees very
sharply in water.
Some animals like octopus have rather big eyes to compensate for the
poor light in the depths of water. Below 300 meters, big-eyed fish need to
capture the flashes of the surrounding organisms to notice them. They have