Topic-Aartificial eye final year seminar full report.

1. i
A
SEMINAR REPORT
ON
“ARTIFICIAL EYE”
Submitted by
ARJUN RAM
in partial fulfillment for the award of the degree
of
BACHELOR OF TECHNOLOGY
(RAJASTHAN TECHNICAL UNIVERSITY, KOTA)
IN
ELECTRONICS AND COMMUNICATION ENGINEERING
UNDER THE GUIDANCE OF
PROF. RITESH SARASHWAT
AT
JODHPUR INSTITUTE OF ENGINEERING AND TECHNOLOGY
MOGRA, N.H. 65, PALI ROAD,
JODHPUR-342802
MARCH& 2016

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Candidate’s Declaration
I hereby declare that the work, which is being presented in the Seminar entitled “Aartificial Eye”
in partial fulfillment for the award of Degree of “Bachelor of Technology” in Department. Of
Electronics & Communication Engineering with Specialization in Electronics & Communication
Engineering, and submitted to the Department of Electronics & Communication Engineering,
Jodhpur institute of engineering and technology, Rajasthan Technical University is a record of my
own WORK carried under the Guidance of Prof. Ritesh Sarashwat Department of Electronics &
Communication Engineering, Jodhpur institute of engineering and technology.
I have not submitted the matter presented in this Seminar anywhere for the award of any other
Degree.
(Name and Signature of Candidate)
Enrolment No.: 12EJIEC705
Counter Signed by
Name of Guide Name of Incharge
..................................... .....................................
..................................... .....................................

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ACKNOWLEDGEMENT
Firstly I would like to express my sincere gratitude to the Almighty for His solemn presence
throughout the seminar study. I would also like to express my special thanks to my seminar
supervisor, Assistant Professor in the Department of Electronics & Communication Engineering
Prof. Ritesh Sarashwat for providing me with valuable advice and guidance of the Department of
Electronics & Communication Engineering For their constructive support and cooperation at each
and every juncture of the seminar study.
We are highly grateful to Prof. O. P. VYAS, Dean (Engineering), JIET for proving us this
opportunity to carry out independent study on this topic.
The divine support given by our guide Prof. RITESH SARASHWAT and Prof. K. K. ARORA,
HOD (M. Tech) & Prof. (Dr.) HEMANT PUROHIT, HOD (B. Tech) Department of
Electronics and Communication Engineering, J.I.E.T, Jodhpur, without them the work would not
be possible.
NAME
ARJUN RAM
ROLL NO
12EJIEC705

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ABSTRACT
For those millions of us whose vision isn't perfect, there are glasses. But for those hundreds of
thousands who are blind, devices that merely assist the eyes just aren't enough. What they need are
alternative routes by which the sights of the world can enter the brain and be interpreted.
Technology has created many path ways for the mankind. Now technology has improved to that
extent where in the entire human body can be controlled using a single electronic chip. We have
seen prosthetics that helped to overcome handicaps. Bio medical engineers play a vital role in
shaping the course of these prosthetics. Now it is the turn of artificial vision through bionic eyes.
Chips designed specially to imitate the characteristics of the damaged retina and the cones and
rods of the organ of sight are implanted with a microsurgery.
Linking electronics and biotechnology, the scientists has made the commitment to the
development of technology that will provide or restore vision for the visually impaired around the
world. This multidisciplinary nature of the ‘new technology’ has inspired me to present this paper.
There is hope for the blind in the form of bionic eyes. This technology can add life to their vision
less eyes.

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TABLE OF FIGURE
FIGURE
NO. FIGURE NAME PAGE NO.
Chapter -2
2.1 Human Eye 6
2.2 Anatomy of the eye 7
2.3
Internal Structure of
Human Eye 8
2.4 How eye work 10
2.5 Implanted chip 12
Chapter -3
3.1 Magnified Image of ASR 13
3.2 ASR Implant in Eye 13
3.3 Full Size of ASR 14
3.4 The MARC System 15
3.5 Circuit of MARC System 15
3.6 Visual System 17
Chapter -4
4.1 Working of Bionic Eye 18
4.2 After Surgery 20
4.3 What the person can see 21
4.4 How Bionic person look 23
4.5 Bionic eye 23
4.6 Manufacturing process 24

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TABLE OF CONTENTS
Title Page i
Candidate’s Declaration ii
Acknowledgement iii
Abstract iv
List of Figures v
Introduction___________________________________________________1
Literature survey_______________________________________________3
Chapter.1 History of Artificial eye_______________________________4
1.1 Background _______________________________________________4
1.2 History___________________________________________________ 5
Chapter.2 System Overview____________________________________ 6
2.1 Human eye________________________________________________ 6
2.2 Human eye condition________________________________________ 6
2.3 Vision Impairment__________________________________________ 9
2.4 Causes of blindness__________________________________________9
2.5 Cornel Transplants___________________________________________9
2.6 How eye work______________________________________________10
2.7 The Surgery________________________________________________11
Chapter.3 System Feature______________________________________12
3.1 Artificial silicon Retina_______________________________________13
3.2 MARC System______________________________________________14
3.3 Engineering Details__________________________________________16
3.4 Visual System______________________________________________17

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Chapter.4 Working Procedure___________________________________18
4.1 Structure of micro detector ____________________________________20
4.2 The prototype Implant________________________________________20
4.3 Implantation________________________________________________20
4.4 Some fact about bionic eye____________________________________21
4.5 The manufacturing process____________________________________23
4.6 Orbital Implants_____________________________________________24
Conclusions___________________________________________________25
References____________________________________________________26
Appendix_____________________________________________________27

8. 1
INTRODUCTION
An ocular prosthesis or artificial eye is a type of craniofacial prosthesis that replaces an absent
Natural eye following an enucleating, evisceration, or orbital exenterating. The prosthesis fits
Over an orbital implant and under the eyelids. Belonging to the community of engineers there is
no frontier that we cannot conquer. If scientists give birth to ideas, then it is we engineers who
put life into those ideas. Today, we talk of artificial intelligence that has created waves of interest
in the field of robotics. When this has been possible, then there is a possibility for artificial
vision. `Bionic eye’ also called a Bio Electronic eye, is the electronic device that replaces
functionality of a part or whole of the eye. It is still at a very early stage in its development, but if
successful, it could restore vision to people who have lost sight during their lifetime. This
technology can add life to their visionless eyes [1].
A bionic eye works by stimulating nerves, which are activated by electrical impulses. In this case
the patient has a small device implanted into the body that can receive radio signals and transmit
those signals to brain through nerves and can interpret the image. One of the most dramatic
applications of bionics is the creation of artificial eyes. Early efforts used silicon-based photo
detectors, but silicon is toxic to the human body and reacts unfavorably with fluids in the eye.
Now, scientists at the Space Vacuum Epitaxial Centre (SVEC) based at the University of
Houston, Texas, are using a new material they have developed, tiny ceramic photocells that
could detect incoming light and so repair malfunctioning human eyes [2].
`Bionic eye,' also called a Bio Electronic eye, is the electronic device that replaces functionality
of a part or whole of the eye. It is still at a very early stage in its development, but if successful,
it could restore vision to people who have lost sight during their lifetime. A bionic eye work by
stimulating nerves, which are activated by electrical impulses. In this case the patient has a small
device implanted into the body that can receive radio signals and transmit those signals to nerves.
One of the most dramatic applications of bionics is the creation of artificial eyes. Early efforts
used silicon-based photo detectors, but silicon is toxic to the human body and reacts unfavorably
with fluids in the eye. Now, scientists at the Space Vacuum Epitaxial Centre (SVEC) based at the
University of Houston, Texas, are using a new material they developed, tiny ceramic photocells
that could detect incoming light and so ‘repair’ malfunctioning human eyes
Today, high-tech resources in microelectronics, Optoelectronic, computer science, biomedical

9. 2
engineering and also in vitreo retinal surgery are working together to realize a device for the
Electrical stimulation of the visual system. Artificial Eye, which works through retinal implants,
could restore sight to millions of people around the world who suffer from degenerative eye
diseases. This technology is still in its infancy, but has progressed to human trials. This report
aims to present a brief overview about the basic aspects of this technology and where it’s headed
prior to World War II, ocular prosthetics were made of specialized blown glass that collapsed to
Form a concave shape. During and after World War II this glass became increasing difficult to
Obtain. Soon, acrylic and other plastic polymers were being used for many of the uses previously
Exclusive to glass. An exciting use of this new material was for artificial eyes, or ocular
prosthetics. Acrylic revolutionized the art and process of making ocular prosthetics. In
comparison to glass, acrylic provided better comfort and fit. Glass artificial eyes frequently
needed replacing and broke easily. Acrylic improved the techniques for making artificial eyes
Such as impression molding, blending and allowed for easier changes in shape, color or size of
an ocular prosthesis.

10. 3
LITERATURE SURVEY
1. Tillman, Walter. An Eye for an Eye, a Guide for the Artificial Eye Wearer. F.A.S.O.,
1987.
2. Johnson, R. Colin. "Joint 'biochip' project eyes artificial retina," Electronic Engineering
Times, September 18, 1995.
3. Munro, Margaret. "Building a better eyeball," Montreal Gazette, April 19, 1995.
4. American Academy of Ophthalmology, 655 Beach St., San Francisco, CA 94109, 415-
561-8500
5. Biomedical Engineering McGraw-Hill: New York, Chicago, San Francisco, Lisbon,
London, Madrid, Mexico City, Milan, New Delhi, San Juan, Seoul, Singapore, Sydney,
Toronto 2003 The McGraw-Hill Companies, Inc.
6. Humayun MS, de Juan E Jr., Dagnelie G, et al. Visual perception elicited by electrical
stimulation of retina in blind humans. Archives of Ophthalmology; vol 114.
7. “Artificial Vision for the Blind by Connecting a Television Camera to the Brain" ASAIO
Journal 2000

11. 4
1. “History of Artificial Eyes”
1.1 Background
Prior to World War II, ocular prosthetics were made of specialized blown glass that collapsed to
Form a concave shape. During and after World War II this glass became increasing difficult to
Obtain. Soon, acrylic and other plastic polymers were being used for many of the uses previously
Exclusive to glass. An exciting use of this new material was for artificial eyes, or ocular
prosthetics. Acrylic revolutionized the art and process of making ocular prosthetics. In
comparison to glass, acrylic provided better comfort and fit. Glass artificial eyes frequently
needed replacing and broke easily. Acrylic improved the techniques for making artificial eyes
Such as impression molding, blending and allowed for easier changes in shape, color or size of
an Ocular prosthesis. An artificial eye is a replacement for a natural eye lost because of injury or
disease. Although
The replacement cannot provide sight, it fills the cavity of the eye socket and serves as a
Cosmetic enhancement. Before the availability of artificial eyes, a person who lost an eye usually
wore a patch. An artificial eye can be attached to muscles in the socket to provide eye
Movement. Today, most artificial eyes are made of plastic, with an average life of about 10
years. Children require more frequent replacement of the prosthesis due to rapid growth changes.
As many as four or five prostheses may be required from infancy to adulthood. There are two
key steps in replacing a damaged or diseased eye. First, an ophthalmologist or eye surgeon must
remove the natural eye. There are two types of operations. The enucleating removes the eyeball
by severing the muscles, which are connected to the sclera (white of eyeball). The surgeon then
cuts the optic nerve and removes the eye from the socket. An implant is then placed into the
socket to restore lost volume and to give the artificial eye some movement, and the wound is
then closed. With evisceration, the contents of the eyeball are removed. In this operation, the
surgeon makes an incision around the iris and then removes the contents of the eyeball. A ball
made of some inert material such as plastic, glass, or silicone is then placed inside the eyeball,
and the wound is closed.

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1.2. History
Early artificial eye makers may not have been creating prostheses at all, but rather decorations
For religious and aesthetic purposes. In the millennia B.C., the people of Babylon, Jericho,
Egypt, China, and the Aegean area all had highly developed arts and a belief in the afterlife.
Radiographs of mummies and tombs have revealed numerous artificial eyes made of silver, gold,
rock crystal, lapis lazuli, shell, marble, enamel, or glass. The Aztec and Inca also used artificial
eyes for similar reasons. The skill of the Egyptian artists was so great that they were probably
asked to create artificial eyes for human use, especially if the afflicted were royalty. In 1579, the
Venetians invented the first prosthesis to be worn behind the eyelids. These artificial eyes were
very thin shells of glass, and therefore, did not restore the lost volume of an atrophied or missing
eyeball. Because the edges were sharp and uncomfortable, the wearers had to remove the eyes at
night in order to get relief from discomfort and to avoid breakage. After the invention of this
glass shell prosthesis, there were no significant advances in artificial eyes until the nineteenth
century. In the early 1800s, a German glassblower by the name of Ludwig Muller-Uri, who made
life-like eyes for dolls, developed a glass eye for his son. Though In 1880, Dutch eye surgeon
Hermann Smelled developed the Reform eye design. This design was a thicker, hollow glass
prosthesis with rounded edges. The increase in thickness restored most of the lost volume of the
eye and the rounded edges gave the patient much more comfort. Germany became the center for
manufacturing glass artificial eyes. Several years later in 1884, a glass sphere was implanted for
the first time in the scleral cavity (the hollowed out interior of the white of the eyeball) after
evisceration. An English doctor, Phillip Henry Mules, used the implant to restore lost volume
and to give the prosthesis some movement. The sphere implant was subsequently adapted for the
enucleated socket as well. Many materials such as bone, sponge, fat, and precious metals have
been used for implants since then, but 100 years later, the Mules sphere is still used in the
majority of cases. Eye sockets with spheres within the scleral cavity following evisceration
continue to result in excellent cosmetic results. For the enucleated socket another solution had to
be found. During World War II, the glass eyes from Germany were unavailable, and therefore
During World War II, the glass eyes from Germany were unavailable, and therefore, the United
States had to find an alternate material. In 1943, the U.S. Army dental technicians made the
First plastic artificial eye.

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2. “SYSTEM OVERVIEW”
2.1 Human Eye
Fig.2.1: Human Eye
We are able to see because light from an object can move through space and reach our eyes.
Once light reaches our eyes, signals are sent to our brain, and our brain deciphers the information
in order to detect the appearance, location and movement of the objects we are sighting at. The
internal working of eye is as follows [3], scattered light from the object enters through the
cornea.
1. The light is projected onto the retina.
2. The retina sends messages to the brain through the optic nerve.
3. The brain interprets what the object is.
2.2 Human Eye Conditions
The purpose of this section is to provide some background on human eye conditions that can lead
to vision loss and eye removal. The journey that leads one to our office is often not a pleasant
One. We feel quite privileged to be involved in the restoration and "return to normalcy" of our
Patients. We hope this information will be helpful. The various sections we cover are:
 Anatomy of the eye
 3 types of eye removal
 Orbital eye implants

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 Possible conditions leading to an artificial eye
 Possible conditions leading to a scleral shell
 Eye care specialists
 Leading causes of eye loss in children
Fig.2.2: Anatomy of the eye
The choroid, which carries blood vessels, is the inner coat between the sclera and the
retina.
 The conjunctiva is a clear membrane covering the white of the eye (sclera).
 The cornea is a clear, transparent portion of the outer coat of the eyeball through which
light passes to the lens.
 The iris gives our eyes color and it functions like the aperture on a camera, enlarging in

15. 8
Fig.2.3: Internal Structure of Human Eye
The eyeball is set in a protective cone-shaped cavity in the skull called the orbit or socket and
measures approximately one inch in diameter. The orbit is surrounded by layers of soft, fatty
tissue which protect the eye and enable it to turn easily. The important part of an eye that is
responsible for vision is retina. The retina is complex in itself. This thin membrane at the back of
the eye is a vital part of your ability to see. Its main function is to receive and transmit images to
the brain. In humans there are three main types of light sensitive cells in the retina. They are [3],
• Rod Cells
•Cone Cells
• Ganglion Cells
There are about 125 million rods and cones within the retina that act as the eye’s photoreceptors.
Rods are able to function in low light and can create black and white images without much light.
Once enough light is available, cones give us the ability to see color and detail of objects. The
information received by the rods and cones are then transmitted to the nearly 1 million ganglion
cells in the retina. These ganglion cells interpret the messages from the rods and cones and send
the information on to the brain by way of the optic nerve [2].

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2.3 Vision Impairment
Damage or degeneration of the optic nerve, the brain, or any part of the visual pathway between
them, can impair vision.
2.4 Causes of Blindness
There are a number of retinal diseases that attack these cells, which can lead to blindness. The
most notable of these diseases are:
1. Retinitis pigmentosa.
2. Age-related macular degeneration
Retinitis Pigmentosa (RP) is the name given to a group of hereditary diseases of the retina of the
eye. In macular degeneration, a layer beneath the retina, called the Retinal Pigment Epithelium
(RPE), gradually wears out from its lifelong duties of disposing of retinal waste products [4].
Both of these diseases attack the retina, rendering the rods and cones inoperative, causing either
loss of peripheral vision or total blindness. However, it’s been found that neither of these retinal
diseases affects the ganglion cells or the optic nerve. This means that if scientists can develop
artificial cones and rods, information could still be sent to the brain for interpretation.
2.5. Corneal Transplants
Surgical removal of opaque or deteriorating corneas and replacement with donor transplants is a
common medical practice. Corneal tissue is a vascular; that is, the cornea is free of blood vessels.
Therefore corneal tissue is seldom rejected by the body’s immune system. Antibodies carried in
the blood have no way to reach the transplanted tissue, and therefore long-term success
following implant surgery is excellent [5].

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2.6 How eyes work?
The light coming from an object enters the eye through cornea and pupil. The eye lens converges
These light rays to form a real, inverted and diminished image on the retina. The light sensitive
Cells of the retina get activated with the incidence of light and generate electric signals. These
Electric signals are sent to the brain by the optic nerves and the brain interprets the electrical
Signals in such A way that we see an image which is erect and of the same size as the object.
Fig.2.4:How Eye Work
At the conclusion of the surgery, the surgeon will place a conformer (a plastic disc) into the
socket. The conformer prevents shrinking of the socket and retains adequate pockets for the
prosthesis. Conformers are made out of silicone or hard plastic. After the surgery, it takes the
patient from four to six weeks to heal. The artificial eye is then made and fitted by a professional
ocularist.

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2.7. The Surgery
This concept of Artificial Vision is also interesting to engineers, because there are a number of
technicalities involved in this surgery apart from the anatomical part. The microsurgery starts
with three incisions smaller than the diameter of a needle in the white part of the eye. Through
the incisions, surgeons introduce a vacuuming device that removes the gel in the middle of the
eye and replaces it with saline solution. Surgeons then make a pinpoint opening in the retina to
inject fluid in order to lift a portion of the retina from the back of the eye, creating a pocket to
accommodate the chip. The retina is resealed over the chip, and doctors inject air into the middle
of the eye to force the retina back over the device and close the incisions. During the entire
surgery, a biomedical engineer takes part actively to ensure that there is no problem with the chip
to be implanted. Artificial retinas constructed at SVEC consist of 100,000 tiny ceramic detectors,
each 1/20 the size of a human hair. The assemblage is so small that surgeons can’t safely handle
it. So, the arrays are attached to a polymer film one millimeter by one millimeter in size. A
couple of weeks after insertion into an eyeball, the polymer film will simply dissolve leaving
only the array behind [6].
The main part in our visual system is the eye. Our ability to see is the result of a process very
Similar to that of a camera. A camera needs a lens and a film to produce an image. In the same
Way, the eyeball needs a lens (cornea, crystalline lens, vitreous) to refract, or focus the light and
A film (retina) on which to focus the rays. The retina represents the film in our camera. It
Captures the image and sends it to the brain to be developed.

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Fig.2.5: Implanted Chip

20. 13
3. “SYSTEM FEATURES”
3.1. Artificial Silicon Retina
The brothers Alan Chow and Vincent Chow have developed a microchip containing 3500 photo
diodes, which detect light and convert it into electrical impulses, which stimulate healthy retinal
ganglion cells. The ASR requires no externally-worn devices. The ASR is a silicon chip 2 mm in
diameter and 1/1000 inch in thickness. It contains approximately 3,500 microscopic solar cells
called “micro photodiodes,” each having its own stimulating electrode. These micro photodiodes
are designed to convert the light energy from images into thousands of tiny electrical impulses to
stimulate the remaining functional cells of the retina in patients suffering with AMD and RP
types of conditions [7].
Fig.3.1: Magnified Image of ASR
Fig.3.2: ASR Implant in Eye
The use of external wires or batteries. When surgically implanted under the retina, in a location
known as the sub retinal space, the ASR is designed to produce visual signals similar to those
produced by the photoreceptor layer. From their sub retinal location these artificial

21. 14
“photoelectric” signals from the ASR are in a position to induce biological visual signals in the
remaining functional retinal cells which may be processed and sent via the optic nerve to the
brain. The original Opt bionics Corp. stopped operations, but Dr. Chow acquired the Opt bionics
name, the ASR implants and will be reorganizing a new company under the same name. The
ASR microchip is a 2mm in diameter silicon chip (same concept as computer chips) containing
~5,000 microscopic solar cells called “Micro photodiodes” that each have their own stimulating
electrode [8].
Fig.3.3: The Dot above the Date on this Penny is the Full Size of the ASR
As you can see in the picture at the top of this page, the ASR is an extremely tiny device, smaller
than the surface of a pencil eraser. It has a diameter of just 2 mm (.078 inch) and is thinner than a
human hair. There is good reason for its microscopic size. In order for an artificial retina to work
it has to be small enough so that doctors can transplant it in the eye without damaging the other
structures within the eye [2].
3.2. MARC System
The intermediary device is the MARC system. The schematic of the components of the MARC
to be implanted consists of a secondary receiving coil mounted in close proximity to the cornea,
a power and signal transceiver and processing chip, a stimulation-current driver, and a proposed
electrode array fabricated on a material such as silicone rubber, thin silicon, or polyimide with
ribbon cables connecting the devices. The biocompatibility of polyimide is being studied, and its
thin, lightweight consistency suggests its possible use as a non-intrusive material for an electrode
array. Titanium tacks or cyanoacrylate glue may be used to hold the electrode array in place [9].

22. 15
Fig.3.4: The MARC System
. The MARC system will operate in the following manner. An external camera will acquire an
image, whereupon it will be encoded into data stream which will be transmitted via RF
telemetry to an intraocular transceiver. A data signal will be transmitted by modulating the
amplitude of a higher frequency carrier signal. The signal will be rectified and filtered, and the
MARC will be capable of extracting power, data, and a clock signal. The subsequently derived
image will then be stimulated upon the patient’s retina [10].
Fig.3.5: Circuit of MARC System
The MARC system would consist of two parts which separately reside exterior and interior to the
eyeball. Each part is equipped with both a transmitter and a receiver. The primary coil can be
driven with a 0.5-10 MHz carrier signal, accompanied by a 10 kHz amplitude modulated
(AM/ASK) signal which provides data for setting the configuration of the stimulating electrodes.

23. 16
A DC power supply is obtained by the rectification of the incoming RF signal. The receiver on
the secondary side extracts four bits of data for each pixel from the incoming RF signal and
provides filtering, demodulation, and amplification. The extracted data is interpreted by the
electrode signal driver which finally generates appropriate currents for the stimulating electrodes
in terms of magnitude, pulse width, and frequency [11].
3.3. Engineering Details
First, for visually impaired people to derive the greatest benefit from an enhanced-vision system,
the image must be adapted to their particular blind areas and areas of poor acuity or contrast
sensitivity. Then the information arriving instantaneously at the eye must be shifted around those
areas. The thrust of all prosthetic vision devices is to use an electrode array to give the user
perceptions of points of light (phosphenes) that are correlated with the outside world. Thus, to
achieve the expected shift of the image across the stimulating electrode array, the camera
capturing the image must follow the wearer’s eye or pupil movements by monitoring the front of
the eye under Infrared (IR) illumination. The eye-position monitor controls the image camera’s
orientation. If the main image-acquisition camera is not mounted on the head, compensation for
head movement will be needed, as well. Finally, if a retinal prosthesis is to receive power and
signal input from outside the eye via an IR beam entering the pupil, the transmitter
Must be aligned with the intraocular chip. The beam has two roles: it sends power, and it is pulse
or amplitude-modulated to transmit image data. Under the control of eye movement, the main
imaging camera for each eye can swivel in any direction. Each of these cameras--located just
outside the users’ field of view to avoid blocking whatever peripheral vision they might have-
captures the image of the outside world and transmits the information through an optical fiber to
a signal-processing computer worn on the body. The chip which is inserted on the retina is coded
using the computer programmatic languages. After the implantation, the working of the bionic
eye is compared with the normal view through necessary algorithms so that measures are taken
that can rectify the abnormalities.

24. 17
3.4 Visual System
The human visual system is remarkable instrument. It features two mobile acquisition units each
has formidable preprocessing circuitry placed at a remote location from the central processing
system (brain). Its primary task include transmitting images with a viewing angle of at least
140deg and resolution of 1 arc min over a limited capacity carrier, the million or so fibers in
each optic nerve through these fibers the signals are passed to the so called higher visual cortex
of the brain. The nerve system can achieve this type of high volume data transfer by confining
such capability to just part of the retina surface, whereas the center of the retina has a 1:1 ration
between the photoreceptors and the transmitting elements, the far periphery has a ratio of 300:1.
This results in gradual shift in resolution and other system parameters. At the brain’s highest
level the visual cortex an impressive array of feature extraction mechanisms can rapidly adjust
the eye’s position to sudden movements in the peripherals filed of objects too small to se when
stationary. The visual system can resolve spatial depth differences by combining signals from
both eyes with a precision less than one tenth the size of a single photoreceptor.
Fig.3.6: Visual System

25. 18
4. “WORKING PROCEDURE”
An artificial eye provokes visual sensations in the brain by directly stimulating different parts of
the optic nerve.
Fig. 4.1: Working of Bionic Eye
A bionic eye works by stimulating nerves, which are activated by electrical impulses. In this case
the patient has a small device implanted into the body that can receive radio signals and transmit
those signals to nerves. The Argus II implant consists of an array of electrodes that are attached
to the retina and used in conjunction with an external camera and video processing system to
provide a rudimentary form of sight to implanted subjects The Argus II Retinal Prosthesis
System can provide sight, the detection of light, to people who have gone blind from
degenerative eye diseases. Diseases damage the eyes’ photoreceptors, the cells at the back of the
retina that perceive light patterns and pass them on to the brain in the form of nerve impulses,
where the impulse patterns are then interpreted as images. The Argus II system takes the place of
these photoreceptors. The second incarnation of Second Sight’s retinal prosthesis consists of five
main parts:

26. 19
 Digital Camera - built into a pair of glasses, captures images in real-time sends images to
microchip.
 Video processing microchip - built into a handheld unit, processes images into electrical
pulses representing patterns of light and dark; sends pulses to radio transmitter in glasses
 Radio transmitter - wirelessly transmits pulses to receiver implanted above the ear or
under the eye
 Radio receiver - receiver sends pulses to the retinal implant by a hair-thin, implanted
wire
 Retinal implant - array of 60 electrodes on a chip measuring 1 mm by 1 mm [12]
The entire system runs on a battery pack that is housed with the video processing unit. When the
camera captures an image-of, say, a tree-the image is in the form of light and dark pixels. It
sends this image to the video processor, which converts the tree-shaped pattern of pixels into a
series of electrical pulses that represent “light” and “dark.” The processor sends these pulses to a
radio transmitter on the glasses, which then transmits the pulses in radio form to a receiver
implanted underneath the subject’s skin. The receiver is directly connected via a wire to the
electrode array implanted at the back of the eye, and it sends the pulses down the wire. When the
pulses reach the retinal implant, they excite the electrode array. The array acts as the artificial
equivalent of the retina’s photoreceptors. The electrodes are stimulated in accordance with the
encoded pattern of light and dark that represents the tree, as the retina’s photoreceptors would be
if they were working (except that the pattern wouldn’t be digitally encoded). The electrical
signals generated by the stimulated electrodes then travel as neural signals to the visual center of
the brain by way of the normal pathways used by healthy eyes -- the optic nerves. In macular
degeneration and retinitis pimentos, the optical neural pathways aren’t damaged. The brain, in
turn, interprets these signals as a tree, and tells the subject, “You’re seeing a tree” [12].
All of this takes some training for subjects to actually see a tree. At first, they see mostly light
and dark spots. But after a while, they learn to interpret what the brain is showing them, and
eventually perceive that pattern of light and dark as a tree. Thus bionic eye helps a blind people
to see the objects and recognize them.

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Fig.4.2: After Surgery
4.1. Structure of the Micro Detectors
The ceramic micro detectors resemble the ultra-thin films found in modern computer chips. The
arrays are stacked in a hexagonal structure, which mimics the arrangement of the rods and cones
it has been designed to replace.
4.2. The Prototype Implant
The first implant had just 16 electrodes on the retinal pad and, as a result, visual information was
limited. The new device has 60 electrodes and the receiver is shrunk to one-quarter of the
original’s size. It is now small enough to be inserted into the eye socket itself. The operation to
fit the implant will also last just 1.5 hours, down from 7.5 hours.
4.3. Implantation
An incision is made in the white portion of the eye and the retina is elevated by injecting fluid
underneath, comparing the space to a blister forming on the skin after a burn. Within that little
blister, we place the artificial retina [2].
A light-sensitive layer covers 65% of the interior surface of the eye. Scientists hope to replace
damaged rods and cones in the retina with ceramic micro detector arrays [2].

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Fig.4.3: What the Person Can See?
4.4. Some Facts about Bionic Eyes
Scientists at the Space Vacuum Epitaxy Centre (SVEC) based at the University of Houston,
Texas, are using a new material, comprising tiny ceramic photocells that could detect incoming
light and repair malfunctioning human eyes. Scientists at SVEC are conducting preliminary tests
on the biocompatibility of this ceramic detector. The artificial retinas constructed at SVEC
consist of 100,000 tiny ceramic detectors, each 1/20th the size of a human hair. The assemblage
is so small that surgeons can’t safely handle it. So, the arrays are attached to a polymer film one
millimeter in size. After insertion into an eyeball, the polymer film will simply dissolve leaving
only the array behind after a couple of weeks [16].
Prototyping Devices
Researchers at Bionic Vision Australia (BVA) have produced a prototype version of a bionic eye
implant that could be ready to start restoring rudimentary vision to blind people as soon as 2013.
The system consists of a pair of glasses with a camera built in, a processor that fits in your
pocket, and an ocular implant that sits against the retina at the back of the eye and electronically

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stimulates the retinal neurons that send visual information to the brain. The resulting visual
picture is blocky and low-res at this point, but the technology is bound to improve, and even in
its current form it’s going to be a major life-changer for those with no vision at all. And the
future potential - even for sighted people - is fascinating. There are two prototypes being
developed to suit the needs of different patient groups [13].
A. Wide-View Device
The first prototype bionic eye, known as the wide-view device, will use around 100 electrodes to
stimulate the nerve cells in the back of the eye. This will allow people with severe vision loss to
see the contrast between light and dark shapes regain mobility and independence. This device
may be most suitable for retinitis pigmentosa patients [14].
B. High-Acuity Device
The second prototype, known as the high-acuity device, will use 1000 electrodes to stimulate the
retina and will provide patients with more detailed information about the visual field, helping
them recognize faces and even read large print. The high-acuity device may be most suitable for
patients with age-related macular degeneration; however, it is still some years before the first
patient tests will commence [14].
C. Diamond Device
Melbourne researchers working to restore sight to the vision impaired believe diamond is the
best material with which to build a bionic eye and hope to have a prototype in testing within the
next few years.
Kumar Gamesman, a physicist helping to design a bionic eye for Bionic Vision Australia at the
University of Melbourne, says metals such as platinum and iridium are currently used for
implants. He says even the hardest metals deteriorate within five to 10 years, which is why
researchers have turned their focus to diamonds. “We made a diamond device so the implant
inside the eye will not deteriorate or will not be damaged by any other means,” he said [15].

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Fig.4.4: How the Bionic Person Looks? Fig.4.5: Fig. 13: The Bionic Eye
4.5 The Manufacturing Process
The time to make an ocular prosthesis from start to finish varies with each ocularist and the
individual patient. A typical time is about 3.5 hours. Ocularists continue to look at ways to
reduce this time. There are two types of prostheses. The very thin, shell type is fitted over a
blind, disfigured eye or over an eye which has been just partially removed. The full modified
impression type is made for those who have had eyeballs completely removed. The process
described here is for the latter type.
1. The oculists inspects the condition of the socket. The horizontal and vertical dimensions and
the periphery of the socket are measured.
2. The ocularist paints the iris. An iris button (made from a plastic rod using a lathe) is
Selected to match the patient's own iris diameter. Typically, iris diameters range from 0.4-
0.52 In (10-13 mm). The iris is painted on the back, flat side of the button and checked
Against the patient's iris by simply reversing the buttons so that the color can be seen through the
dome of plastic. When the color is finished, the ocularist removes the
Conformer, which prevents contraction of the eye socket.
3. Next, the ocularist hand carves a wax molding shell. This shell has an aluminum iris
Button imbedded in it that duplicates the painted iris button. The wax shell is fitted into
The patient's socket so that it matches the irregular periphery of the socket. The shell may
Have to be reinserted several times until the aluminum iris button is aligned with the
Patient's remaining eye. Once properly fitted, two relief holes are made in the wax shell.
4. The impression is made using alginate, a white powder made from seaweed that is mixed

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With water to form a cream, which is also used by dentists to make impressions of gums.
After mixing, the cream is placed on the back side of the molding shell and the shell is
Inserted into the socket. The alginate gels in about two minutes and precisely duplicates
The individual eye socket. The wax shell is removed, with the alginate
Fig.4.6: Manufacturing Process
4.6 Orbital Implants
Should eye removal be necessary, the surgeon will likely place an orbital implant to recover?
Some of the volume lost in the evisceration or enucleation. The orbital implant is attached to the
4 rectus muscles, providing movement of the implant with the fellow eye. Typically, the better
The movement of the implant, the better the motility of the artificial eye or scleral shell. Implant
choices may be dictated by the conditions indicating eye removal, the surgeon's
Preference and your post-removal objectives. Most implants are spherical in shape, but other
Shapes are possible. Implants can also be coated or wrapped in donor sclera or alloderm
Materials. Below is a list of typical orbital implants: While implant type is an important decision
to one facing enucleation or evisceration, the most
Important factor is surgical technique. If you are facing the option of eye removal, we
Recommend that you contact your local ocularist for a recommendation of oculoplastic or
Ophthalmic surgeons in your area.

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CONCLUSION
Bionic devices are being developed to do more than replace defective parts. Researchers are also
using them to fight illnesses. If this system is fully developed it will change the lives of millions
of people around the world. We may not restore the vision fully, but we can help them at least to
find their way, recognize faces, read books, distinguish between objects such as cups and plates,
above all lead an independent life. Though there are a number of challenges to be faced before
this technology reach the common man, the path has been laid. It has enabled a formerly blind
patient to. But with only 16 electrodes, the device does not allow the patient to see a clear
picture. For that, thousands of electrodes are neede on the same size of the chip.The bionic eye
has changed the world of the visually challenged people.We are sure that higher quality,better
resolution,even color are possible in the future.Restoration of sight for the blind is no more
dream today.Bionic eye have made this true.

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REFERENCES
1. www.studymafia.org
2. NAGARJUNA SHARMA “BIONIC EYE”, SCRIBD, 2010.
3. American Academy of Ophthalmology, 655 Beach St. San Francisco, CA 94109, 415-
561-8500.
4. http://www.eyenet.org/aao_index.html (http://www.eyenet.org/aao_index.html).
5. Ocular Surgery News. http://www.slackinc.com/eye/osn/osnhome.htm
6. http://www.slackinc.com/eye/osn/osnhome.htm.
7. "Integrated Orbital Implants." http://www.ioi.com
8. http://www.questia.com/library/1G168842005/twoviewsofartificialeyes
9. Artificial Intelligence with 'Eyes' ; IBM Buying Company to Enhance Medical.
10. http://www.questia.com/library/1P238597390/Artificial intelligence eye

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APPENDIX
Researchers are already planning a third version that has 1,000 electrodes on the retinal implant,
which they believe could allow for facial-recognition capabilities and hope to allow the user to
see colorful images. Scientists believe the immediate goal after achieving above is to develop a
functioning artificial retina with resolution that mimics human sensors. Once this step has been
achieved, they says, then attention can be brought to bear on color vision, followed by the
replacement of some of the interconnecting neural cells that lead to the optic nerve. So, let us
hope to reach all these goals as soon as possible. The researchers note the device has some
limitations, and it will not restore perfect vision. However, they are sure it will give people the
advantage of having a general sense of their surroundings. Hopefully, the technology may enable
people to recognize faces and facial expressions. “The thing is to significantly improve the
quality of life for blind patients"
A bionic eye works by stimulating nerves, which are activated by electrical impulses. In this case
the patient has a small device implanted into the body that can receive radio signals and transmit
those signals to brain through nerves and can interpret the image. One of the most dramatic
applications of bionics is the creation of artificial eyes. Early efforts used silicon-based photo
detectors, but silicon is toxic to the human body and reacts unfavorably with fluids in the eye..