Animal and Insect Eye
In order to better understand the perfection of God's creation, look at only a few of the millions of other examples of His art. As it says in the Qur'an, all creatures are under His complete control:
Insects view the world through thousands of tiny eyes.
There is instruction for you in cattle. ... (Surat an-Nahl, 66)
A countless number of organisms are living on this planet; and millions of different insect species alone. Of all the different types of eye, the human eye is the most superior overall, although the eyes of some species boast of features that are superior to those of humans. There are as many different types of eye as there are species, and we have already shown how impossible it is for such a variety to evolve through mutations and natural selection.
God has given every organism an eye that suits their lifestyle and feeding habits. In this section, we'll examine the eye structures of many different species.
Compared to human eyes, the eyes of insects are considerably different. Their structures come in one of two types, simple or complex.
Simple-structured eyes are round and small, capable only of separating light and dark. Compound eyes, on the other hand, are larger and more complex, made up of hundreds of small pieces. Each "piece" is actually a small eye because it contains light sensitive cells, a lens, and connections to the brain.
The wide visual perspective of a fly's eyes.
As mentioned before, a human eye's lens can change shape, letting us focus on objects at various distances. The lens in an insect's eye cannot change shape, however, and so insects cannot focus.
The compound eye works by each of the eye's six-sided compartments (called ommatidia) detecting a tiny portion of the visual field. The information from each ommatidium is then combined, like pieces of a mosaic, to form a single image of the outside world. The higher the number of ommatidia, the keener the vision becomes, with each unit contributing a different part of the complete picture.35
The head of the common housefly is dominated by a pair of large compound eyes containing approximately 4,000 ommatidia. In wingless insects such as female fireflies there are 300 ommatidia, 5,100 in mayflies, 9,000 in yellow-winged coleopterans and between 10,000 and 28,000 in dragonflies and damselflies.
A Visual Range of 360 Degrees
The housefly's eye contains 4,000 small, simple ommatidia which can be moved at will. Since each ommatidium faces a different direction, the fly is able to see to the front, back, left, right, top and bottom, giving it a 360 degree perspective of the world.
Each ommatidium is sensitive to light shining in its direction, and uses its own lens and eight sensitive cells to process it. House flies have a combined total of 48,000 light-sensitive cells, allowing them to see 100 images per second. In this regard, their vision is ten times superior to the human eye. Two-thirds of the fly's brain is devoted purely to sight. The total number of light-sensitive cells means that 48,000 signals are sent here every tenth of a second.
Thanks to the flawless design of its eyes, the housefly can look 360 degrees around. At left, a detailed diagram of an ommatidium, of which the fly's eye contains some 4,000.
Most people think of the fly as one of the most basic forms of life, but its visual system is in fact one of the most complicated we know.
A tiny fly did not evolve or mutate its 4,000 eyes over a period a time. Clearly. This is a special creation. Of course, the fly is not composed of merely its visual system—it also has special digestive, reproductive and flight systems. Only with all its systems intact can the fly thrive. It is not possible for a fly to exist, for example, without a digestive or respiratory system. Nor are there any blind insects flying around! This is solid evidence that the fly was created by God in its current state, as mentioned in the Qur'an:
Mankind! An example has been made, so listen to it carefully. Those whom you call upon besides Allah are not even able to create a single fly, even if they were to join together to do it. And if a fly steals something from them, they cannot get it back. How feeble are both the seeker and the sought! (Surat al-Hajj, 73)
An Insect with 56,000 Eyes
Among all known species, dragonflies have the greatest number of ommatidia. Each eye contains 30,000 of them,36 which can clearly see objects up to 20 feet away.37
To recap this phenomenon, a single tiny insect has a total of 56,000 eyes, each of which has a lens, retina, and thousands of nerves connecting it to the central nervous system. As a result of this, the dragonfly can see its prey and understand what it is seeing.
The presence of just a single eye with a single neuron and the ability to evaluate a single signal is a miracle on its own. But there are thousands of these eyes, all working in complete harmony. This is just another of God's countless phenomenon. God is the One Who has no equal in creation.
Butterflies and bees both possess a special sense of sight, allowing them to reach sources of food with ease.
In some flowers, the pigments form distinct patterns that are invisible to us, but visible to bees and butterflies, who can see ultraviolet light. Called nectar guides, these patterns are like the landing strips of an airport, directing the insects to the nectar within the flower. It is as if their food sources were lit up and signposted especially for them. To our eyes, the coneflower appears to be a uniformly yellowish orange, but to a bee or butterfly, it appears as a corona of yellow with a glowing ultraviolet bull's eye in its center. This pattern guides the bee to where it can collect the nectar or pollen.
Bees' eyes are sensitive to ultraviolet light; enabling them to find pollen in flowers with ease. Their eyes were designed by the All-Knowing and All-Seeing God.
Bees feed on the pollen produced by plants. The plants, on the other hand, need the bees to spread their pollen among other flowers of the same species in order to reproduce. Therefore, the flower uses its petals to attract the bee and sticks pollen onto the bee's legs as it feeds. Both partners possess the necessary features to enable this collaboration. Imagine a situation wherein flowers continued to reflect in the ultraviolet range, but bees were unable to see that portion of the spectrum. Both species would swiftly go extinct, because the bee would not be able to feed, nor the flower to reproduce. This is proof that these co-dependent organisms were created by the same Creator.
For a flying creature, the most important sense is sight, because the miracle of flight would become a very dangerous affair without the ability to see. Birds, therefore, have been blessed by God with a superior sense of sight, in addition to the ability to fly.
A bird's sense of sight has a wider perspective and can operate much more quickly than a human's can. An object or view that we humans have to regard at length, a bird can see as a whole, in one quick glance.
Eyes are crucial for the predator owl, which can see ten times more 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 perform precisely accurate hunting maneuvers.
Larger eyes contain more visual cells, providing better vision. A predator 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 other species. Looking for food, these predator birds search for small animals on the ground, and their eyes can pick up the slightest movements, thanks to a high number of light-sensitive rods in their retinas. As we explained, the more rod cells, the keener night vision becomes. But for this vision, predator birds do pay a price: They sacrifice the sense of color. They see the world in black and white but, owing to their lifestyle, they do not need to see color. So cone cells are quite fewer in the eyes of nocturnal birds.
During the past minute, as you read this book, you blinked 22 times. That's how your eyes maintained their moisture and cleanliness. But for that split-second that you blinked, your eyes stopped doing their job. For the relatively sedate lifestyle of a human, this may not be a problem. But for a bird in 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 experimenting?
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 look at an object, both our eyes are directed toward the object. This allows our brain to merge both the images to create a sense of depth. The eagle contains a binocular fovea like ours, but also has a fovea for monocular vision that allows each eye to look sideways and see a separate image. So eagles can see both forward and to the side at the same time.40
The eagle has a visual perspective of some 300 degrees, as well as an extra focusing power. Humans change the shape of their lenses to focus. But an eagle can change the shape of both lens and cornea. This gives it extra focusing power.41 It can also scan a 30,000-hectare (116-square mile) field from an altitude of 4,500 meters (14,700 feet), or spot a camouflaged rabbit from 90 meters (300 feet) with ease.42
To attain this super-sharp vision, an eagle's retinal cells are tinted with special colored oil droplets, increasing the contrast for objects seen against the blue sky or green forest. Thanks to this, the eagle can spot minute changes in contrast from thousands of meters above and swoop down to hunt. The fact that a mere drop of oil makes this possible is doubtlessly one of God's countless blessings.
Flying is a miracle in itself. If one aspect of the present structure or position of a bird's wing were changed, it would be unable to fly. Therefore, it isn't possible for wings to have evolved over time.
As mentioned before, something else that couldn't possibly have evolved is the visual system. This is reinforced by the flawless nature of an eagle's eye. An eye with two foveae cannot form over time, as a result of coincidences. That second fovea was deliberately created to answer the bird's needs.
For an eagle, that droplet of oil in its retina cells is of staggering importance... But who made this fine optical adjustment? Did the eagle add the oil himself, or on other animals' recommendation? Of course not. The eagles have enjoyed this feature from birth, for thousands of years.
So why are our eyes not as sharp as an eagle's? If human eyes contained the same features, they'd each be the size of a grapefruit. Moreover, humans don't need to spot a camouflaged rabbit from a kilometer away. This is why God gave humans their present eyes in a most aesthetic form.
Compared to ordinary spiders, the jumping spider leads a very unusual life. Rather than make a web and wait for a catch, these spiders hunt their prey instead. This is why—unlike ordinary spiders, which are almost blind—they have exceptionally acute vision.
A jumping spider hunts by securing itself to the branch of a tree with the thread it secretes. Then it throws itself toward an insect flying nearby, catching it in midair. In order to snare its catch, the spider needs to see its prey, and determine the direction and speed at which the target is traveling. Also, of course, it must determine its own speed and the duration of the leap. In order to do all this, the spider needs not only an advanced visual system, but an information processing center to make all the necessary calculations.
Jumping spiders have four pairs of eyes, for a total of eight. The front two are the most impressive, perhaps the best eyes one can find in any arthropod. The retina inside the eye can move in three dimensions, enabling the spider to look in all directions and focus on its subject. The other six eyes are positioned around the head, affording 360-degree vision.43
The jumping spider's visual acuity is actually very similar to our own, such that they even perceive images on a television screen. When most animals look at a television, they see only a series of moving dots. But research has indicated that jumping spiders respond to televised pictures of other spiders and insects.
The jumping spider's visual system is highly complex and, in some respects, surpasses even a human's. A tiny spider can look in different directions, detect motions, and estimate speed and distance. Of course, the spider never asked for these abilities, nor did it develop them on its own, over time. Everything the spider possesses was given to him by God.
The Protection of Animal Eyes
As the body's most sensitive organs, the eyes must therefore be well protected. This is why animal skulls have been constructed in such a way as to provide their eyes with maximum protection.
In animals like cats and dogs, the majority of the eye lies inside the skull, with only a small portion protruding outside. The bones surrounding the eye effectively act as a shield against impacts, and the eyelids help protect against direct injury.
The eyes of a camel—a mammal that lives under incredibly harsh conditions—are provided with the protection they need. The bone structure around its eye not only protects it from impacts, but also from harsh sunrays. Not even violent sandstorms can harm a camel's eyes, thanks to its eyelashes, which are long and intertwined, preventing any dust from entering.
Eyes in the Sea
There are considerable differences between land and underwater creatures, because under the surface is effectively another world, whose inhabitants have been modeled to best suit their environment. But just because they spend their lives underwater doesn't mean that their basic requirements are any different from ours. To stay alive, they still need to breathe, feed and avoid being hunted. They have to be able to see the world around them, so that they can distinguish between prey and foe—and require special eyes that let them see clearly underwater.
BFish view their world through a transparent layer that covers their eyes, similar in principle to the goggles worn by human divers. But be it a whale or a herring, an underwater creature's field of vision is restricted. Deeper than 30 meters (99 feet) below the surface, distant vision becomes unnecessary. Most of the time, in fact, fish need to see only those objects directly in front of them, and their eyes are created to meet this need. Their rigid, globular lens is particularly adapted for seeing close objects. But when they do need to see at a distance, a set of special muscles pulls the entire lens back toward the retina.44
The spherical lens in a fish's eye works well underwater. Because of the higher degree of refraction (the bending of light) in water than in air, a fish's lens has to be much more curved than a human's. To produce a clear image, the lens bends the light a lot more than does a flatter one—such as those in humans and other land animals.45
Water creatures are always in danger of becoming food for larger creatures. But they do have a special defense mechanism not seen in mammals: Fish can perceive more than one image at the same time.
A fish's eyes are placed on either side of its head. The image seen by each eye is recorded in the opposite half of its brain. But since the image is viewed by one eye only, it is two-dimensional, which prevents the fish from judging distances. This is why, when it spots some potential threat, both eyes focus in the same direction to judge the distance. Straight ahead, the visual arcs of the two eyes overlap to provide a narrow band, where the fish enjoys binocular vision.
With the exception of a few species, fish cannot see in color. They have no need to, because only a few meters underwater, most colors are absorbed and disappear. A fish's entire world is mostly shades of blue and green.
Fish are more sensitive than land animals to dim light, because their retinas contain a higher number of cells sensitive to low intensities, letting them make use of every amount of light possible.
Sea turtles generally feed on fish. In the process, they also consume a large quantity of sea salt, which could be unhealthy if they digested it. Rather than simply eject salt from the body, the turtle transfers it to special sacs located on to the side of its eyes. Here, the salt is cleverly recycled and used to produce tears.46
Of all the invertebrates, the octopus has one of the most complex eye structures. As in vertebrates, each of the octopus's two large, complex eyes is like a camera, in structure, and the creature's vision is acute.
The octopus eye and the vertebrate eye are extraordinarily similar. Each includes a cornea, an iris, an accommodating lens, a fluid-filled vitreous humor, and a retina. However, there are major differences. For instance, octopi change their range of focus by moving the entire lens closer or farther away from the retina, whereas we change the shape of our cellular lens in order to bring objects into focus.
But if the two species developed separately, why are their eyes so similar? It seems that the impossible has taken place not just once, but at several times and in several places. If the human eye is the product of coincidences and not creation, then shouldn't it be considerably different than the octopus's eye? The theory of evolution simply cannot answer thousands of basic questions like this.
The Archer Fish
This fish is famous for being a living water pistol—filling its mouth with water and squirting it at insects resting on branches or twigs above the water. The element of surprise causes the insect to lose its grip and plunge into the water, where it becomes an easy catch.
What's remarkable about the process is that even as the archer fish prepares itself, it doesn't raise its head out of the water. While still submerged, it can accurately determine the insect's location. But the apparent position of objects outside the water is distorted by the retraction of light. For example, if you wanted to shoot an arrow from beneath a swimming pool at a point in the air outside, you'd have to know at what angle light retracts upon the water and adjust your aim accordingly.
But this fish seems to overcome this problem and shoots on target every time. It is able to hit a tiny insect with no difficulty.47 All archer fish possess this ability, but not through lessons and physical calculations. It is God Who inspires this creature.
The Crab's Periscope
A crab has two eyes on the ends of stalks. These act like little periscopes, allowing the crab to see what's going on above, even if it is hiding beneath the sand. At any sign of danger, the stalks can be lowered for protection into sockets on the carapace.
Most reptiles can see a large array of colors, allowing them to pick out even the most effectively camouflaged insects. This gives them a major hunting advantage.
Most reptiles can see a large array of colors, allowing them to pick out even the most effectively camouflaged insects. This gives them a major hunting advantage.
On most species of snakes, the eyes are placed on either side of the head, which produces two different images in the snake's brain. However, this location of the eyes doesn't stop the snake from seeing forward. In fact, this positioning gives the snake a wide visual perspective, allowing it to look forwards, backwards and upwards with ease.
As you've seen, the human eye can perceive only a specific range of wavelengths of light. Some species of snake are capable of seeing greater wavelengths than humans, including infrared light, which humans can sense only as heat.
Snakes have small pit organs that can visually register infrared radiation. These organs are a hundred thousand times more sensitive to infrared than human skin and can detect even the slightest change in a body's temperature.
For example, the rattlesnake can locate a warm-blooded animal or human even in pitch darkness, because such creatures radiate off heat waves that the snake can detect—an incredible advantage for any creature hunting at night.
The principle of detecting objects and soldiers by the heat they emit is also used in recent optical military equipment. It took years of research to develop the technology behind this kind of equipment, but snakes enjoy the same ability from the moment they hatch from their eggs. It took decades for humans to develop heat-sensing equipment, but snakes have always had it.
There are vast differences between a reptile's eyelids and the eyelids of other creatures. It may appear as if snakes do not have eyelids, for example, but their eyes are in fact covered by an immobile, transparent layer of scales.
Lizards, on the other hand, have movable eyelids. But in the desert lizard especially, the eyelids are upturned. This keeps out the sand, preventing it from harming the eye when the lizard buries itself in the sand.
The Sensitive Eyes of a Frog
Recent research has revealed some of the frog's eye's interesting abilities. One kind of retinal cell responds strongly to small, dark, round moving objects and is most active when those objects moved irregularly. It is as if the neurons of the frog eyes were designed especially to detect flies. Some scientists call their eyes "bug detectors."49
The eye of a cat contains a layer called the tapetum lucidum, not found in humans. Positioned immediately behind the retina, it reflects incoming light, doubling the amount of light the eye can use and allowing cats to see in much dimmer light than we can. This layer is also the reason why cat eyes seem to glow when a flashlight beam is shined directly at them.
Cat eyelids are prized wide open at night, allowing as much light as possible to enter. Another reason why cats can see so well in the dark is because their retinas contain more rod cells than cone cells. Thanks to this system created by God, wild cats can comfortably hunt at night.
35. Niko Tinberg, Animal Behovior, 2.b., Hong Kong: Life Nature Library-Time Life Books, ss. 53-54.
36. Ibid., p. 13
37. "The Dragonfly," Norma Jean Weeks, Miami Valley Water Garden Society; http://www.mvwgs.org.ragdonflies.htm
38. "OWL HOUSES: Providing houses for cavity-nesting owls," http://www.coveside.com/merchant/owls.html
40. “Structure & Anatomy,” http://peabody.vanderbilt.edu/projects/funded/sft/eagle/stru.htm
41. “Animal Eyes,” http://www.astc.org/exhibitions/eyes/texteyes.htm; “Vision: An In-Depth Look at Eagle Eyes,” http://www.learner.org/jnorth/tm/eagle/VisionA.html
42. Tony Feddon, Animal Vision, BLA Publishing Ltd., New York, 1988, p. 25
43. “The Zebra-Spider in 3D,” Wim van Egmond, Micscape Magazine;
44. “The Sensory World of Fishes,” http://www.csuchico.edu/~pmaslin/ichthy/Snsry.html
45. “Seeing in Water, Seeing in Air,” http://www.foothill.net/~malamud/web/aquatic/light.html
46. “Turtles That Went To Sea,” Flotsam and Jetsam A Newsletter for Massachusetts Marine Educators, Fall and Summer 2002, Volume 31, no. 1; http://www.massmarineeducators.org/journal/f_j_summer-fall2002.pdf
47. Tony Feddon, Animal Vision, BLA Publishing Ltd., New York, 1988, p. 40-41
48. “Chameleons Head;” http://freespace.virgin.net/chameleon.hh/head.htm
49. “Chapter 6, Vision I: The Eye,” http://www.utsc.utoronto.ca/~milgram/nroc64/vision1.htm