Chapter 2. Biological Eye  Designs

Chapter 3. Eye
 Design Illustrations
A. Plant light sensing
1. Grass, simple vines, 
and stems
2. Flowers
B. Lower animal eyes
1. Flatworms
2. Clams and Scallops 
3. Nautilus
4. Shrimp
5. Crab
6. Octopus and 
   giant squid
7. Spiders
8. Scorpions
8. Brittle Star 
C. Insect eyes 
1. Bees
2. Dragonflies
3. Butterflies
4. Flies
5. Ants
6. Moths
7. Beetles
8. Wasp
D. Fish eyes 
1. Shark
2. Flounder
3. Four-eyed fish 
E. Amphibian eyes
1. Frog
2. Salamander
F. Reptile eyes
1. Boa constrictor 
2. Rattle snake
3. Lizard
4. Turtle
5. Crocodile and 
    alligators
G. Bird eyes
1. Eagles
2. Hummingbirds
3. Owls
4. Ostrich
5. Cormorants
H. Mammal eyes
1. Whales
2. Elephants
3. Lions, tigers, and 
   other cats
4. Monkeys
5. Rats and mice
6. Bats
7. Tarsier
I. Human eyes
1. Iris
2. Lens
3. Retina

Chapter 4. Eye 
 Reproduction

Chapter 5. Optical 
 Systems Design 

Chapter 6. The Eye Designer

Related Links

Appendix A - Slide Show & Conference Speech by Curt Deckert

Appendix B - Conference Speech by Curt Deckert

Appendix C - Comments From Our Readers

Appendix D - Panicked Evolutionists: The Stephen Meyer Controversy
 

 
 
 
 
 
 
 

EYE DESIGN BOOK
Chapter 3
Section C
-  Prev Page            Go to Chapter Links -             Next Page - 

(Click on PICTURE IN TEXT to bring up LARGE PICTURE)

3. EYE DESIGN ILLUSTRATIONS
C. Insect eyes
     Insects have even more different types of eyes and vision systems than the less advanced animals we've considered. Many insects need to see in three dimensions while flying at high speed. Indeed, winged insects have better vision than wingless ones. The variation of eye size, resolution, and overall optical design in insects is also great. 
Many insects see a wider spectrum of colors than humans do. Their color vision spectrum may vary from ultraviolet, in the case of the bee, to near infrared, in the case of some butterflies, and beetles. Insects need to be able to see colors and shapes to find plants for food and protection, and to identify each other. Some plants are uniquely designed and colored to reflect UV light and other specific colors to attract suitable insects to carry out their significant role in pollinating flowers. 
     The many purposes for vision, such as survival, eating, protection, etc., result in eyes designed for the specific environments of each creature. For example, insect vision can take place at the rate of up to 300 frames per second for fast-moving flying insects. This is a significant design development, because of the size, speed, field-of-view of each facet, number of facets, and programming required for insects to function. 
Many insects have compound eyes, similar to lobsters and other arthropods. Insect eyes are primarily apposition and superposition types. These types of optical designs are discussed in Section II. Here some acuity or resolution is sacrificed for increased sensitivity. There are also day vision and night vision types of compound eyes and eye that are very versatile. A wide variety of insect vision systems exist because of the extreme variations in size, function, and environment. 
     In some very small insects, the density of photoreceptors per square millimeter can be as large as in a human eye. This provides for sensing of small images, even for insects, in very small packages. However, since these eyes are very small, there are fewer total photoreceptors than in human eyes, so there is much less total resolution over the whole field of vision. For example, it is very unlikely that insects can see stars in the sky.
     Also, some small insects have as large a density of connections to the brain as in the human eye, but since the total volume is far less there are fewer connections. Connecting visual links in some insects may have more density than those contained in human eyes. However, depending upon the depth of focus, most insect compound eyes would have to be more than 50 times larger than they are to match the overall resolution of the human eye. Because of this, insects may have vision that only approaches that of humans over a very limited field and distance. 
     Size and configuration of insect eye optics vary according to function. Because of fixed focus eyes, many insects must move in close to get a good view. Ideally, the resolution of multi-faceted eyes can be more uniform over the whole field of vision than that of a camera eye, since these fixed focus eyes are made up of a large number of smaller, somewhat independent, optical systems working together. The facet size within an eye varies according to size and the specific priority of directional and field-of-view needs of a particular insect. 
     Iridescent corneas are present in some insect eyes. These iridescent tin film filters pass some colors and block or reflect others. This allows insect photoreceptors to have varied and extended color capability. This effect can help insects see UV more clearly than human eyes can. Optic lobes of insects also contain highly developed image processors for use by their small brains. 

1. Bees       Bees may have 3,000 to 4,000 facets, or small lens systems, that make up each of their eyes. They also may have multiple photoreceptors for each lens or facet of the compound eye. The center facets are larger than peripheral sensors, so insects can see better straight ahead. The effective numerical aperture, or f-number, of a bee's eye facets is about the same as a human's eye. However, the ratio of a single facet area to that of the human eye active-sensing area is a factor of 10,000. This means they do not have the total resolution capacity to see as well as humans. Some small eye photoreceptors are only about one micron in size. The formation of such an eye requires advanced optical design and very specialized biological manufacturing design for reproduction.       Bee eyes sense polarization of visible light in the sky and also have sensitivity to UV light. They seem to see blue colors best, but they also see ultraviolet colors beyond the blue colors which humans see. Don't forget that a yellow flower may have markings that reflect or absorb light in the UV region. Flowers may also have narrow-band color reflections that communicate to bees and other animals the type of plant it is. Bees' extended range of color vision helps them to locate flowers and food to function in their survival and growth.       Bees use a unique means of communication. By sensing polarized light they get a sense of direction and then use visual codes to signal food locations to the other bees in the hive. To do this, they dance while flying at a specific angle relative to the sun to define direction. Then they use the speed of their movements to indicate the distance to other bees. In addition, when in the hive, they communicate with a circular dance in a compact  location to tell where specific nectar is located. Here, the frequency and wiggle indicates the distance. Direction comes from relating the position of the sun to the location of the food, also com- municating by using the angle of dance relative to the direction of gravity. This communication takes considerable visual processing and perception from within their small brains. (Fig 3.13, p 64 lower, Readers Digest, Exploring the Secrets of Nature, 1994)  (Fig 3.13b, (c) Micro- Angela. B&W images colored for visual effect.)      Figure 3.13c, d, and e are photos of various bee eyes by Geoff Woodard, who has a number of excellent insect and other photos on the web. These photos help to illustrate some of the variation of Bee Eyes.

Figure 3.13a New Queen  Honeybee Eyes. Figure 3.13b Honeybee Eyes. Fig 3-13c Green Bee Eye. Figure 3-13d Bee Face

Figure 3-13e Bee Eye

Figure 3-13f Group of Bees

2. Dragonflies      Some extinct dragonflies had wingspans of 24 inches. Even though their descendants are now smaller, they still have large compound complex eyes with very wide-angle vision to allow them to see as they fly forward and backward. Like other insects, dragonflies have to position their eyes by changing their body orientation, since their eyes do not move. Each of the dragonfly's compound eyes is made up of about 30,000 eye sensors, so they have better resolution than many  other insects. The overall photoreceptor density can be about the same as humans. However, since dragonflies' eyes are much smaller than human eyes, they do not have as much overall resolution and sensitivity. Using binocular vision as humans have, dragonflies are able to estimate distance based on the distance between their eyes. See figure 3.14a-c for a view of the complexity of the overall dragonfly.      Figures 3.14a and b are photos of Dragon Flies by Geoff Woodard, who has a number of excellent insect and other photos on the web. These photos further illustrates the variation of dragon fly Eyes and their extreme angular coverage. They actually use their stereo vision to determine distance as they intercept targets.

Figure 3.14a Dragonfly Eyes.

     (Fig 3.14c from P. 325, Readers Digest, Exploring the Secrets of Nature, 1994 -- Fig 3.15 from P. 68, Megabugs, The Natural History Museum Book of Insects, Barnes & Noble, N.Y., Miranda MacQuitty with Laurence Mound)
     See Figure 3.15 for the damselfly eye design.

Fig 3-14b Dragonfly Full Wing.

Figure 3.14c Dragonfly Eyes.

Figure 3.15. Damselfly Eyes.

3. Butterflies
     Depending on the species, small butterflies have either apposition eyes or some similar type of eye optics. Butterflies of various colors and designs need to see a wide spectrum of colors in order to find food, survive and multiply. Butterflies may have up to four different pigments in their eyes, as compared to two or three in many other insects. As a result, some butterflies have wide-spectrum color vision allowing them to see UV light reflected from specific flowers. Others can also see near-infrared-light beyond human color vision limits. They seem to respond to image color more than image detail, but their eyes have enough resolution to see fine patterns in flowers, and to see other butterflies in order to fly together. Some butterflies can see 30 micron (.03mm) details on objects, while the human eye can see details only in the range of 100 microns (.1mm).  One possible reason for this variation is the large difference in eye focal lengths. The butterfly's eye, with short focal length, is able to focus closer than the human eye. Normally, human eyes can focus better at a longer distance, over a wider field, than butterfly eyes.
     Butterfly eyes are shown on the following figure. There are some similarities with moth eyes shown in later chapters. (Figure 3.16 from p.110, Megabugs, The Natural History Museum book of insects, Barnes & Noble, N.Y., Miranda MacQuitty with Laurence Mound. Figure 3.16b & c, courtesy of www.pbrc.hawaii.edu/bemf (c)MicroAngela 

Figure 3.16a Butterfly Eyes.

Figure 3-16b Butterfly Eyes - front view

Figure 3-16c Butterfly Eyes - side view

4. Flies      Fruit flies have very small compound apposition eyes that require neural processing. They can sense rapid motion approaching 200 cycles per second. Considerable image  processing is confined to a very small space. Fruit flies and other related specieshave been known to grow as many as three eyes, but we do not know if they can process with all three eyes. Third eyes may come from genetic errors due to induced genetic damage from toxic sprays, defective experimental genetic engineering or the normal background mutation rate from a very large number of experiments. It would be interesting to see if the third eye also contained the necessary programming in the brain to take advantage of improved overall sensitivity from the redundant eye.  (P. 17, Megabugs, The Natural History Museum book of insects, Barnes & Noble, N.Y., Miranda MacQuitty with Laurence Mound. Figure 3.16b - e, courtesy of www.pbrc.hawaii.edu/bemf (c)MicroAngela )

Fig 3.17a Fly Eye Figure 3.17e Fly Eye

Figure 3.17b Fly Eye

Figure 3.17c Fly Eye

Figure 3.17d Fly Eye

Figures 3.17f, g, h, and i are photos of Flies eyes by Geoff Woodard, who has a number of excellent insect and other photos on the web. These photos illustrate some of the variations in fly eyes. The Navy is studying Fly Eyes to help develop guidance systems for weapons and more compact optical sensors. Hopefully, their intelligent vision processing will provide new technology for weapons, robotics, or other future applications.

Fig 3.17f Fly

Figure 3.17g Fly Eye

Fig 3.17h Green Eyed Fly

Fig 3.17i Young Fly Eye

5. Ants
     Most ants have poor vision because they have a smaller number of sensors for their vision. Their vision is comparable to a small fruit fly's. For example, at the low end of  viewing capability, the dark-adapted underground ant has only nine facets per eye. But ants make good use of other senses such as smell, to supplement vision from their small apposition eyes. One would expect that their brains require considerable pre-programming of various operations, to coordinate their functions with limited vision.

They also have a significant communication system as demonstrated by the way ants function together in groups such as army ants. The ant's visual processing system is very simple and compact for its unique purpose.(Fig 3.18 from P. 119, Megabugs, The Natural History Museum book of insects, Barnes & Noble, N.Y., Miranda MacQuiton with Laurence Mound.  Fig 3.19 from Pg. 113 Bugs, Bloodsuckers, Bacteria and More by Peter Brookesmith, Barnes & Noble, 1999. Figure 3.19b, courtesy of www.pbrc.hawaii.edu/bemf (c)MicroAngela )

Figure 3.19a Ant  Eye detail

Figure 3.18 Ant Eyes.

Figure 3.19b Black Ant Eyes.

Figure 3.19c Ant Eye Detail. (From page 28-29 Creation, Dec 2001 to Feb 2002)

6. Moths

Some varieties of moths have the ability to see color at night, but in general, color night vision is rare. It is thought that some varieties may use stars or the moon to guide very long flights. Three- dimensional image processing for moths has to take place in a very small volume. This is amazing, because of all the flight control intelligence needed in the brain for moths to fly. As a means of defense, moth eyes absorb a high percentage of light so that very little light reflects from them. Some moth eyes have an anti-reflective (AR) coating with low protection so they can blend in with their surroundings. This very low eye reflection is very difficult for man to design into optical systems.

Figure 3-20 Moth eye Detail.

     This type of coating found on a moth is just now being used commercially, such as for production of anti-reflective coatings on solid plastic and other lenses. It would seem to be even more difficult to control these intricate small anti-reflective coating patterns on living tissue. The size of the elements on the A/R coating are on the order of 200nm. (Pg. 109 Laser Focus World, Aug. 1999) 
 

Figure 3.21 Moth Eye (Like Fig. 2-14) (Pg. 113 Megabugs, The Natural History Museum book of insects, Barnes & Noble, N.Y., Miranda MacQuitty with  Laurence Mound.)

Figure 3.22 Fine detail on Moth's  Eye showing Anti-reflective Coating Surface (P. 109 Laser Focus World, Aug. 1999)

7. Beetles
     Beetles are expected to give scientists some new information on building efficient infrared detection systems. This could be used for night vision, fire detection, and other functions. Beetles use this capability to sense forest fires. Beetles have refraction superposition eyes which is a more advanced optical design as compared to apposition eyes. See figure 3.23 for a beetle eye. (Figure 3.23, p. 100, National Geographic, Vol. 193, No. 3, March 1998. Figure 3.23b courtesy of www.pbrc.hawaii.edu/bemf (c)MicroAngela   B&W images colored for visual effect.).

Figure 3.23a Beetle Eye

Figure 3.23b Cigar Beetle Eye

     Here we have sampled only a few insect eyes. One could make a lifetime study of insects and still only scratch the surface of the vast variety of insect eye design variations. Studies of the size, materials, and functions of these small eyes could help solve significant design problems occurring in today's image technology. 

8.Wasp      Figures 3.23 is a photo of Wasp eyes by Geoff Woodard, who has a number of excellent insect and other photos on the web. These photos illustrate wide angle wasp eyes. A number of people are studying Wasp Eyes to learn more about their compact optical sensors and intelligent vision processing. Hopefully this work will provide new technology for future vision system applications.

Figure 3.23c Wasp Eye