Wonders of Creation: Different Vision Systems

For many sea-dwelling animals, seeing is extremely important
forhunting and defense. Accordingly, most of the sea-dwelling animals
are equipped with eyes perfectly designed 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 thedensity 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 withinthe eye.
One other reason why the eyes ofthe 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 ofwater. Below 300 meters, big-eyed fish need
to capture the flashes of the surrounding organisms to notice them.
They have to be especially sensitive to the feeble blue light
penetrating into the water. For this reason, there are plenty of
sensitive blue cells in the retina of their eyes.
As is understood from these examples, every living being has
distinctive eyes specially designedto meet its particular needs. This
fact proves that they are all created just the way they have to be by
a Creator Who has eternal wisdom, knowledge and power.