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 D
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3. EYE DESIGN ILLUSTRATIONS
D. Fish eyes
     Fish have fairly complex camera eyes, some of which are extremely elegant and versatile in design. Fish eyes need to be highly developed, since many are sight-feeders rather than smell-feeders. Some have the ability to see both above and below the water. They have good spatial resolution and color vision. Fish have flattened corneas, rather than the higher curvature corneas of land animals, because of the need to match the different index of refraction requirements of water rather than air. Even if the fish eye’s cornea does not contribute to overall optical correction, it still acts as a window to the water. Water deeper than 15 meters acts as an optical filter to exclude most infrared and ultraviolet light, so there is less need for most fish to have extended color vision.

1. Shark
     Shark eyes need to handle wide water pressure variations, as they range from shallow to deep water looking for food. The inner eye and retina have to compensate for pressure differences on the eye’s outer surface. Their eyes are relatively small for the overall size of their bodies. Since the shark’s visual acuity has been sacrificed for more sensitivity to low-light vision, it probably sees a lower resolution image than humans. 

There are a variety of sharks each having slightly different eyes. For example, the hammerhead shark has eyes on lobes that extend from the head. This is probably for an improved stereo effect to increase the ability to estimate distances to targets for high-speed interception. The eyes of the blue shark and others have more typical spacing, but they still need a fair amount of resolution to hunt for their food. The following figures illustrate shark eye exterior and section views. (p. 110, Vision in the Animal World, R. H. Smythe, Macmillan Press, 1975)

Figure 3.24 Cross Section of a  Typical Shark Eye

Figure 3.25 Horn Shark Eye  (by Bruce Chambers)

Figure 3.26 Blue Shark Eye  (P. 323, Readers Digest, Exploring  the Secrets of Nature, 1994)

2. Flounder 
     The eyes of the flounder have a unique placement. These flat bottom-dwelling fish frequently need to hide in the sand from predators. Since both of their eyes are on the same side of their bodies, they can watch for predators when they lie flat in the sand. This seems to be a fundamental feature of the flounder, but not at birth. 

Figure 3.27 Flounder Eyes.

Figure 3.27a Flounder Eyes in sand (Both figures from Pg. 61,  Eyes Of Nature, National  Audubon Society, 1968,  Nelson Doubleday)

3. Four-eyed fish
      The four-eyed fish has a unique eye configuration. Each eye lens has one facet for looking out of the water and another for seeing in it. This complex eye lens can focus two images simultaneously from above and below the water so it is called a four-eyed fish. These fish eyes are large and bulging, like those of a frog. Because it can see out of the water, it is difficult for fishermen to catch this fish.

The complex processing requirements;for the brain from the four images, coupled with its elegant optical design, make it easy to believe that the eyes of this fish were specifically designed. (P. 324, Readers Digest, Exploring the Secrets of Nature, 1994)        Figure 3.28a gives us an idea as to the actual complexity of some Eyes that may appear to be fairly simple designs. Gradient index is used in many insect, animal, and probably in human eyes. This correction afforded by gradient index can allow a wider clear field of view with fewer optical elements.       (Reference: Figure 4.3, p. 59, Animal Eyes, Michael F. Land, Dan-Eric Nilsson, Oxford Animal Biology series, Oxford University Press, 2002- Please see their book for more details )       Figure 3.28b illustrates elegant design of an aquatic Eye. Such designs are somewhat consistent with contemporary optical design where considerable optimization issues to create very effective vision systems. (Reference: Figure 4.10, p. 69, Animal Eyes, Michael F. Land, Dan-Eric Nilsson, Oxford Animal Biology series, Oxford University Press, 2002- Please see their book for more details)

Figure 3.28 "Four-eyed Fish Eyes." Figure 3.28a Example Of Fish Gradient Index" Figure 3.28b Aquatic Triplet Eye Lens"