Chapter 2. Biological Eye  Designs

Chapter 3. Eye
 Design Illustrations

Chapter 4. Eye 
Reproduction

Chapter 5. Optical 
 Systems Design 

A. Introduction

B. Manufactured optics 
1. Astronomy and 
surveillance
2. Stable platform for 
optical systems
3. Robotic camera 
applications
4. Flying robotics
5. Microscope and 
endoscopic applications
6. New technologies to see building blocks of cells

C. Present vision system technology approaches toward artificial eye development 

D. Integration of mans technology with 
biological eyes 

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 5
Sections C and D
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5. OPTICAL SYSTEM DESIGNS LEADING TO 
       ARTIFICIAL EYES 
C. Present Vision System Technology Approaches Toward 
Artificial Eye Development
     New optical system designs are usually developed for very specialized tasks. For example, machine vision systems use complex lighting and optical systems to form images on camera sensor for a particular purpose.

Only a few wires are used for serial computer processing of electronic camera images. Some new camera sensing systems have limited processing intelligence on detector chips in order to approach some of the advantages of retina parallel processing. There may be millions of interconnections on a computer chip, but very few output signal conductors. Human sight, as we know it, would be much more difficult without some pre-processing of the parallel image data coming from 125 million rod sensors. The diagram in figure V-i shows the necessary functions of visual development required beyond the optical function. The vision processor design is even more complex than the basic eye optics. (Pg. 4, Neuro-Vision Systems, Ed. by Madan M. Gupta, George K. Knopf, IEEE Press, 1994)

Figure 5-22. Visual Function  for Vision Systems beyond the  optical function. Like fig. 4-03

     Some new imaging innovations are starting to function similar to nature's eyes. The first example is a wide-angle motion sensor device developed in Australia. It is patterned after a multifaceted or compound insect eye. There are considerable applications for this type of wide-angle sensor. It uses a small microchip optical sensor that sees and thinks, to make simple decisions based on its vision. The sensor actually sees a shadow of an object, much as some insects do with their limited brain processing power. These new sensors are examples of parallel processing, with separate control of each of the many sensors. Hopefully, more of nature's eye designs can also be applied to motion detection for applications such as detecting blind spots for vehicle on roads and for robotic forklifts in a warehouse.

These designs can be applied to function at UV, visible and IR wavelengths, by designing with materials that will transmit the required wavelengths.      Considerable effort has been focused on developing visual aids for people with little or no natural vision. Some progress is being made in artificial eye development to aid vision where it is flawed or missing. Figure 5-23 shows one approach to an artificial retina. (Pg. 32, Vision System Design, June 1999)

Figure 5-23 Concept for  artificial retina inserted  as part of retina

Artificial retinas are being pursued for a variety of purposes, such as partially replacing key parts of human vision. Some of these are beyond an active display providing an  image directly on the retina. They will actually try to transmit some type of image data directly to extensions of optic nerve cells. The design of man-made eyes is made extremely difficult because of the wide range of lighting conditions under which human eyes typically function. For example, it is often very difficult for man-made vision systems to see clear high-resolution color images in very low light conditions. The following figure notes another future concept for an artificial retina. {Pg. 20, IEEE Spectrum, May 1996)       Systems presently under development, to be marketed several years from now, are expected to be able to aid those who have no vision or very poor vision. For example, new work on artificial eyes at the University of Michigan, North Carolina State University, John Hopkins University, and the University of Texas at Austin is being done using microchip and other related technology. Some claim spectral capabilities beyond those of the human eye, but their usability remains to be seen. Their eye consists of a series of micro-mechanical lenses less than a millimeter in diameter.

Figure 5-24 Toward an  artificial eye Figure 5-25 An Implanted  Array in the retina and supporting Camera System

     This device makes use of tunable lasers on the chip for transmission of information to a suitable interface in the existing eyes. By designing components with appropriate materials, one could then see in UV, visible, or IR wavelengths. The following approach shows one possible way to aid the retina with an implanted array. (Pg. 20, IEEE Spectrum, May 1996)
     This approach can use a series of variablebr focus lenses in one module, while another module is used to process information coming over optical fibers. Here the speed of information transfer could be great, but the technology required for systems with large numbers of parallel channels needs to be developed. Many researchers are just beginning to appreciate the human eye. 

A number of smart cameras, or camera sensors with computing functions on the same chip, are being built and sold for machine vision applications. These smart cameras are beginning to cut in on other markets requiring more expensive computer interfaces and  software. Additionally, the task of interfacing power and information to eyes is a significant task. One way to accomplish that is shown in Figure 5-25. Manufacturers are starting to integrate computer and image sensor chips. So far, these smart cameras are limited to fairly simple inspection tasks where the object orientations and light are quite constant. The variety of motion that can be accommodated by this vision system may be quite dependent on the lighting.      As we further study nature's eye systems, we may be able to take advantage of eye designs that can be developed for new products using new manufacturing technology. Technology extracted from nature's eyes is opening new doors. Remote analysis of medical problems using recognition systems may be one of the best application opportunities for new vision technology. For example we may pattern recognition systems after biological vision systems like feature detection shown in figure 5-26. (Pg. 11, Neuro-Vision Systems, Ed. by Madan M. Gupta, George K. Knopf, IEEE Press, 1994) (Fig 5.29b adapted from 1999 Eye Poster from Anatomical Chart Co. Skokie, IL)

Figure 5-26a Representative  Visual Stimuli along  the visual pathway Figure 5-26b Representative  Visual Stimuli along  the visual pathway

In Figure 5.26c retinal implant is shown in front of eye. This retinal implant, developed in Germany, is made up of a series of sensors and LEDs to replicate a very crude image and projected it onto the retina. With the new emphasis on MEMS technology, there are many different approaches to a retinal implant. This particular implant would only give very crude sight over a limited angular field of view, where the total number of pixels would probably be < 1 percent of the total in a normal healthy eye.      In Figure 5.26d retinal implant is shown relative to Eye. Small Times is a new publication devoted to MEMS technology. Using MEMS technology is possible to configure a variety of retinal implants. This implant is designed to stimulate nerve cells and improve vision through time release of a drug. Again, the present state of technology cannot provide a high-resolution image that can presently be integrated with the optic nerve. There are other approaches being developed, but some of the best approaches may be to aid the present eye structure.

Figure 5.26c Retinal implant Shown in front of eye (page 9, Optics and Photonics News, Jan., 2002) Figure 5.26d Retinal Implant shown relative to Eye (page 55, Small Times, Nov./December 2001)

Figure 5.26e shows a potential new retina implant that may help the millions of people that have blindness from degeneration of the photoreceptors in the retina. Optobionics has a wireless scheme of connecting and interfacing to implanted vision devices in the retina. The micro channel glass array matrix contains millions of micro wires implanted between a multiplexer and the retina. DARPA, universities, and other groups have also been active in this field. For some of these concepts, scanned images are introduced to the implant from an outside camera device.(reference: SPIE OE Magazine, July 2002, page 10)      Figure 5.26f shows the relative resolution of a ceramic micro detector for an implant as compared to human cones of the retina shown in the background. One can see the resolution is not real great, but for the million peoples that are afflicted with macular degeneration, this could be a great improvement of sight. Here ceramic photocells that mimic the function rods and cones are expected to absorb light and generate a photo voltage to fire the neuron cells.

Figure 3.26e Potential Retina Implant. Figure 5.26f Retina Implant Resolution.

     Several different groups are working on various methods of providing implants into the retina. The implant needs to be biocompatible and stable. Human trials are expected to begin in 2003. (reference: Biophotonics International, April 2002, page 26)
     Second Sight was founded in 1998 to create a limited retinal prosthesis to provide sight to blinded patients. By mid 2003 they have developed, built, and implanted a simple visual prosthetics to enable blind individuals to achieve greater independence by seeing 16 pixels of information at one time. They are currently developing more advanced implantable devices with more pixels that use power and data from an external camera and electrically stimulates the retina through an array of electrodes. Further, research conducted by Second Sight has shown that more advanced array designs with more pixels are possible. This will significantly improve the quality of the images seen by patients. In his 2000 State of the Union Address, President Clinton referred specifically to Second Sight's research,
     "Scientists are also working on an artificial retina to help many blind people see.".
     Second Sight is conducting one FDA approved device study and has approval for another. If someone you know is interested in participating in one of these trials, please go to their web page for additional information. Patients eligible for consideration are those with a confirmed history of retinal degenerative disease in the worse-seeing eye with remaining vision no better than light perception (see links section).
     Second Sight received FDA approval to conduct clinical trials to evaluate the feasibility of using electrodes to provide electrical stimulation of the retina to elicit visual percepts in blind subjects. In the early study the device was removed at the end of the test. The longer-term clinical trial is to evaluate the feasibility of utilizing a retinal stimulation system (Reference: Second Sight Web site and LINK Conference).

D. Integration of man's technology with biological eyes.
     By applying millions of hours of design, using today's technology on new vision systems, scientists are evolving sensors that will have similar vision to some natural eyes. Early, relatively crude experiments have been done when very low-resolution imaging has occurred. It is not expected that they will ever equal the total capability of human eyes in the area of healing and reproduction. This technology may aid us in treating nature's eyes. 

Natural healing features of eyes may also be accelerated through application of new medical technology to provide alternative answers to vision problems. The following figure illustrates one way that vision may be improved by cell replacement. This is very controversial because of the use of fetal tissue. (Pg. 26, Time, Fall, 1997, J. Madeleine Nash}      Just getting eyes, or even parts of eyes to reproduce or repair, is still a major mystery. DNA codes couldprovide clues to future development of accelerated repair or growth of specific flawed parts of eyes. This will require discovery of a means of understanding  how original DNA plans are implanted, then using the built-in chemical manufacturing capabilities to generate the specific cells at the location needed for repair. Cell communication is expected to be necessary to provide some means of controlled internal repair. This will require advances of biological and other sciences to determine the communication necessary for working with each particular type of cell. For example Figure 5-28 is a classification of possible neural networks that are possible from what we are learning about vision systems.

Figure 5-27 Cell  Replacement Concept Figure 5-28 Neural network  structures that have possible  applications to vision (Pg. 22, Gupta and Knopf, IEEE Neuro-Vision Systems IEEE Press, 1993)

     Even though building simple artificial eye optical systems may be feasible, the process of interfacing artificial eyes to a brain is expected to be far more difficult than actually building the optics, sensors, and processing electronics for input to the eyes. There will also be considerable cost to manufacture and integrate new vision aids for eyes. Naturally, use of as many of existing components should be used. For example, if a brighter image is put on the retina then the integration process is much easier. 
     Cell interface complexity multiples with some eye sensor cells having different communication channels than others. There is a greater possibility to encourage the repair of specific parts of an eye from its master plan, than to reproduce whole eyes in a test tube, and then transplant them. For example, certain herbs, drugs and light can aid the healing process within the eye. Because of the interfacing with cells, it would seem more likely to encourage new cells to grow into their correct locations. New communication development has to take place for this to happen. More research is needed to define the total visual process in terms of the DNA structure.
     Here we have researched some of the wide variety of eye designs. It is exciting to see the beginning of a merger of man's artificial and nature's living eye designs such as using laser implants in eyes to transmit data from a camera to an artificial retina segment. This merger infers intelligent design, even to replace an existing lens or group of sensors with artificial ones that can improve poor vision.