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WIDESIGHT

CERTEC REPORT 2:1997


Bodil Jönsson, CERTEC, Lund Institute of Technology
Jörgen Gustafsson, Low Vision Center, County Hospital Ryhov, Jönköping

Widesight tree

Illustration: Ingrid Wigur. (Idea: Bodil Jönsson.)


Translation: Anna-Karin Batcheller Layout: Anu Uus

Table of Contents

Preface
Summary
Introduction

The Roots of the Widesight Tree
1. PEER
2. Low Vision Center Experience
3. Multilens
4. Rolf Öhman

The Crown and the Branches of the Widesight Tree
1. Raytracing
The Sven-Göran Pettersson Program
The Tübingen Program
Opera
2. Development of Measuring Methods
The Scotoma Lens Jenny
Measuring Peripheral Vision
3. Development of Visual Aids
Optical Glasses for Widesight
A New Type of Contact Lens
Electronic Glasses for Widesight

Appendix 1. PEER - Documentation on the Internet (Lars Philipson, Bodil Jönsson)
Appendix 2. RAY TRACING - A List of References (Lars Åke Svensson)
Appendix 3. Our First Trial with Raytracing Programs for the Eye (Sven-Göran Petterson)




Preface

The Widesight branch of research has only one clear fundamental idea, but it develops a number of methods for demonstrating the convincing force and possibilities of this idea.

THE IDEA IS THAT AN INDIVIDUAL'S PERIPHERAL VISION MAY HAVE MANY MORE APPLICATIONS THAN HAS PREVIOUSLY BEEN BELIEVED!


We believe that no reader of this report will fail to sense what the implications might be if this theory holds up. It could result in drastic changes for some visually impaired people. And it may be of great importance to all drivers, for example.

This is the first report in which we present both the idea and the methods of the project. It is necessary but, at the same time, impossible for us to write it and thereby capture an image of the research tree, Widesight, as it is at the moment.

Widesight tree

It is necessary, because the number of results has been, and still is, growing very quickly, causing us too readily to dismiss some shoots as blind shoots, without having the time to or the ability to or perhaps even attempting to examine them on the basis of a pattern which has emerged only later. Consequently, we need this documentation to aid our own reflection process as a kind of mock-up for our thoughts. It is also needed in order to provide information to people outside the project, to our colleagues at CERTEC and Ryhov and to the research world and the low vision world in Sweden and abroad. Particularly during the last three months, it has seemed an almost insurmountable task to convey something of Widesight to a previously uninitiated person. It has become obvious that a very considerable amount of background description is required.

Our keynote address to the conference of the Swedish Association for Low Vision Rehabilitation Employees (FFS) at Saltsjöbaden on October 22, 1997, made it imperative to elaborate a structure to follow, to share with others, and, yes, to hand out. We are very grateful to the FFS Association and to Harry Svensson for providing the necessary pressure - many things became visible through the structure we imposed on ourselves. The structure is represented by two trees, and this report is really only a way of captioning the pictures of those two trees.

Widesight tree

PEER tree

And yet, why does it still feel almost impossible to produce this piece of documentation? A commonplace answer would be the obvious one that devoting time to documentation requires a great deal of discipline we could have done so many new things during this time, and that would have been terribly exciting. And so much easier. Because writing this is difficult. How do we adjust the focus, the depth of field and the shutter of our documentation eyes? Which aspects can be documented in sharp focus, what is lost in the distance, how much do we include?

Ett suddigt Widesight träd

Enough subterfuge! Here is our report. We believe that the passing of time, i.e. the next six months, will help distinguish the brilliant parts from the mediocre ones.

Lund, November 10, 1997.

Bodil Jönsson
Jörgen Gustafsson

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Summary

Peripheral vision in humans has been considered necessarily poor as a physical matter since vision receptors are sparse away from the macula lutea.

This is not the first time in human history that half-truths, such as this one, have become almost axiomatic and appeared as the whole truth by being repeated often enough. For various reasons we came to ask the counter-question: do we really know that our peripheral vision has to be as poor as it is?

While working on PEER, Research on Extraordinary Eye Perception, an on-going project, we started getting ideas as to how it might be possible to model, examine, and improve peripheral vision. And that is the subject of this report.

The main objective of Widesight is to bring about a paradigm shift in our view of what peripheral vision can be used for. In order to succeed in this aim, we are developing and testing new ways of thinking and teaching, new methods of diagnosis and new products. Accordingly, Widesight is a research project in the sense that it generates new knowledge. We also believe that it will generate new devices and new diagnostic instruments.
Ett öga There are three branches to this project:
  • Raytracing
  • Development of new measuring methods
  • Development of visual devices


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Introduction

Widesight is focused entirely on the possibility of utilizing peripheral vision more efficiently.

Peripheral vision is important to everyone. Often, people with full vision are not aware that they are using their peripheral vision and they usually feel that its most important function is that of forewarning. Normally, for people with impaired vision, the most important function of peripheral vision is that it can help them see just enough to find their way about.

However, peripheral vision is usually treated as the kid brother of central vision: only in central vision is visual acuity considered possible. This has also been the experience of many people: when their central vision is lost or reduced, they are left with a seriously disabling visual impairment. Some of these diseases of the eye occur in young people, but most sufferers are older people with macula degeneration. This group is growing.

The following is a mix of our ideas, the work we have done the basis of these ideas, how we intend to proceed, the roots and the branches, and how they are interconnected.

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The Roots of the Widesight Tree

Trädet Widesights rötter: PEER

1. PEER

PEER, Research on Extraordinary Eye Perception, is Widesight's most important root. PEER is outlined at http://www.arkiv.certec.lth.se/research/projects/peer/. The project description written by Lars Philipson and Bodil Jönsson, and the article by Peter Sylwan of the Science Department at the Stockholm daily newspaper Dagens Nyheter, both of which can be found at this site, are reproduced in the Appendix.

PEER logo

Actually, PEER can also be viewed as a tree the tree that dropped the acorn which produced the Widesight tree. So, in order to explain how PEER is the root of the Widesight tree, let us examine the mother oak, PEER itself.


PEER tree

Illustration: Ingrid Wigur. (Idea: Bodil Jönsson.)


In short, PEER is concerned with the fact that some blind people - by this we mean people who have been diagnosed as blind with no ability whatsoever to see objects or distinguish light from darkness can take in information through their eyes other than the information sighted people get from ordinary image vision. The fact that something called blindsight exists in some blind people has been known for several decades and has been published in various research contexts. Some blind people are able to perceive direction without being able to see objects, discern movement, or see color without being able to see shape, etc. It is also possible that they have a circadian rhythm which is controlled by the intermediary of their eyes. In addition, they may have balance sight, which means that their ability to keep their balance is influenced by their eyes just as for sighted people.

More specifically, we wished to investigate circadian rhythm sight and balance sight. The idea of circadian rhythm sight was not our own it had been introduced and studied in Boston (see above URL). However, it has been further developed in the PEER project, where the melatonin variation in blind people not only was measured but also treated very successfully by the carefully controlled administration of medication. The idea was generated by us at PEER, but the people who have done most of the work in this area are Eva Carlholt, Ophthalmic Nurse, and Werner Polland, Senior Consultant, head of the Department of Ophthalmology in Jönköping. The results will be published.

Balance sight is an original idea by Lars Philipson. He has also been the driving force behind the balance measuring device which has been designed and stationed at Ryhov Hospital and the measuring which has been and will be carried out at that location.

Balantestest Balantestest


The rotating pattern in the periphery strongly affects the balance of sighted people, and the shift in the center of gravity between the feet which occurs when a person is swaying is measured with the aid of two balance plates. How strongly the person is affected depends on a large number of factors, for example whether the test subject has the appropriate optical correction.

Glasögon

Preliminary results indicate that the balance of some blind people is also affected by a rotating pattern in the periphery.


Does this mean that blind people ought to wear glasses? In our experience, glasses seem to be effective in some blind people, although we do not have a substantial amount of statistical data to support this claim.

The best test is of course whether a blind person experiences a difference between having her eyes shut and having them open.

Do blind 
people have any ability to keep their balance while standing
on one leg?

For blind people who do experience a difference, it might be worthwhile to try the "rooster test" as well. Sighted people are able to stand on one leg, and keep standing for a long time, but if they close their eyes they immediately find it difficult to keep their balance. What about blind people? Do they have any ability to keep their balance while standing on one leg? And if so does it make a difference whether they close their eyes? We have actually met at least one woman who clearly experiences this phenomenon.

The rooster test The rooster test


This has been a tour of the roots and branches of the PEER tree. The only remaining part which needs commenting on is the root "Experiences from Tomteboda, AMI-syn, etc." (resource centers for people with visual impairments). Obviously, as soon as the idea arose that some blind people may use their eyes for things which others cannot, many associations sprung up in the minds of professionals with extensive experience of blind people. We have received many testimonials from rehabilitation care professionals as well as from blind people.

Resource centers 
for people with visual impairments

Finally, the acorn "Widesight" is lying on the ground, dropped by PEER, the mother tree. It is no coincidence that this acorn is lying under the branch "balance system measuring" because it was our experience in that area that lead to our investigation of peripheral vision in sighted people.

Widesight

PEER in the community
Quite naturally, PEER has been received with a mixture of amazement and skepticism. However, the results are such that not only do they deserve respect in their own right, but so does the thinking behind them. For example, we very successfully communicated both PEER and Widesight to professionals working in low vision (re)habilitation they understand, they recognize some aspects, are amazed at others, and are stimulated to further thinking. For our part, we are continuing our work - it is simply so exiting that nothing can stop us. But it is also difficult.

Obviously, thinking along new lines entirely is the biggest difficulty. In addition, there are practical difficulties, such as a lack of funding. Although the sum by no means corresponds to the amount of work we have invested in the project, we were very pleased to receive a grant of 100,000 Swedish kronor from the foundation "Stiftelsen Synfrämjandets Forskningsfond" in the fall of 1997 we actually view this as a first formal recognition.

We are hoping to receive much more substantial financial support in the future. Perhaps we will even be contacted directly by financial backers who are impressed by the results we have achieved. With greater financial resources our work would be faster and better and we would have an opportunity to investigate other effects which this paradigm shift may have on eye perception, in addition to the ones we have examined so far.

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Root: Low vison center experience

2. Low Vision Center Experience

All low vision centers in Sweden, but in particular the one at the County Hospital Ryhov which is involved in our research on a regular basis, have at least two functions in Widesight. One is to be a driving force by contributing the vast amount of experience they have acquired over more than 20 years they know exactly what problems need solving. Their other function is to be able to take a theoretical idea and say "but, in that case …" or "I knew it!". Previously, we have described how experience from, for instance, the Tomteboda and AMI-syn resource centers can be viewed in a new light when they are provided with a different theoretical foundation through PEER. Naturally, the same thing applies to how partially sighted people use their eyes.

An Example:
According to the theoretical calculations performed in the Widesight project, a positive correction of several diopters is required in order to even get close to an image on the retina in peripheral vision. When Jörgen Gustafsson of the Low Vision Center at Ryhov was confronted with this claim, he said: "Well, in reality I knew that already…".

Because this how it is:
A large and rapidly expanding group of patients at the vision centers are older people suffering from macula degeneration. What is typical for these patients is that they lose their central vision while their peripheral vision is usually unaffected. Consequently, they are able to move about without difficulty but they cannot read in the normal manner, that is, without aids which enlarge the text.

When examining the refractive errors of these patients, the low vision center optometrist often finds that when the patient is provided with the correction which the optometrist has established is right for the patient using objective measuring methods, it does not agree with what the patient wants. Many patients with loss of function in the macula want a correction which is more positive than the one which has been arrived at objectively. Sometimes, it is a matter of 2-3 diopters. This is surprising, but has usually been attributed to the enlarging effect of the correction.

What if it is simply the case that new measuring methods and completely different glasses (not just with respect to strength) are needed for peripheral vision than are presently used for central vision? Compare the section on Raytracing below.

We believe that when we proceed with an optical description of what takes place in the eye, some of our conclusions will match other experience stored up at low vision centers around the country. For instance, some patients who have had complicated eye surgery on several occasions have refractive anomalies which have never been explained, but which it may soon be possible to describe, perhaps even to correct, by the use of improved methods of optical diagnosis for eyes and for computer models.

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3. Multilens

The low vision centers would not be getting very far if it were not for companies with the ability to manufacture the special optical devices which are sometimes needed. Similarly, early on in our project we identified the need for close collaboration with an optical company - not just in view of the aids which may be developed in the future, but also for our present research. It was no coincidence that the company turned out to be Multi Lens, since it is the only one of its kind in Sweden and it also has many connections abroad.

The correction of refractive errors with the aid of glasses has been well known for a long time. Among lens manufacturers there are many large and widely known companies, such as Zeiss, Rodenstock, AO, Essilor and a considerable number of small and lesser known ones. Almost all of these companies (particularly the big ones) share a lack of interest in the unorthodox which is often essential in impaired vision optics. Multilens is the exception. Since his days as an optician student, and subsequently as an employee of AO and RX-Optic and now at Multilens, Lars Hellström, the founder of the company, has lived by the philosophy that "nothing is impossible". This philosophy fits exceptionally well with CERTEC's belief that "you cannot know until you have tried."

Multilens has achieved excellent combinations of glass and filters. In particular, the development of multi-focal glass for eye-glasses with unusual combinations of high strengths in both diopters and prisms has made it a world leader in the field. Now, the company is entering the telescopic systems market. And they will form a root in Widesight since they have the capability of developing, for example, optical instruments for measuring the eye's refraction of peripheral rays as well as methods for fitting glasses for peripheral vision at a low vision center, for example.

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Roten

4. Rolf Öhman

Perhaps the heading for the third root described above, Multilens, should have been Lars Hellström. Because it is his creativity that is contributing to Widesight's growing power. Likewise, we are debating in our minds whether to label the fourth root "Rolf Öhman" or "Just Electronics".

However, there is no doubt in our minds about the existence of the root, and we have decided to call it "Rolf Öhman". Rolf has a solid background as a research engineer at the Ophthalmology Clinic at Lund University Hospital. He has developed various measuring tools and has published scientific reports in collaboration with other scientists. He is a combination of brilliant inventor, designer and a person who has a profound understanding of the functioning of the eye. In short, he is a unique person (who, incidentally, has even received a gold plaque from the Royal Swedish Academy of Engineering Sciences for "outstanding technological research").

In the PEER project he has been involved in the development of the balancing equipment, and in Widesight he is behind the idea that it may be possible to measure peripheral vision directly in the eye.

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The Crown and the Branches of the Widesight Tree

The Crown and the Branches of the Widesight Tree
The crown has three areas:


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1. Raytracing

We are performing trials with raytracing, i.e. following the path of rays of light into a computer simulated eye. To a high degree this is pioneering work, which involves bringing together knowledge about the curvature of the cornea, the optical characteristics of the lens and the bend of the retina into a collected whole in a computerized form which allows it to be used with individual data.

Raytracing

Computer simulated ray paths have existed for the last 20 years. They have become increasingly sophisticated. But until a few years ago nothing had been done for the eye. That is one of many indicators of the distance between ophthalmology and ophthalmologic surgery on the one hand and basic and applied optics on the other. It is extremely rare for people with a knowledge of the inner structure of the eye to have optics skills as well.

The fact that trials of raytracing for the eye have been reported in the literature in recent years is almost exclusively due to excimer laser operations and the need for more differentiated knowledge of the effects of changes in the curvature of the eye. A list, compiled by Lars-Åke Svensson, of articles relating to computer-simulated eyes can be found in appendix 2.

So far, however, there have not been any studies focusing specifically on peripheral vision.

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The Sven Göran Pettersson programme

The Sven-Göran Pettersson program

Sven-Göran Pettersson, PhD, research engineer at the Department of Physics at the Lund Institute of Technology, was very happy to participate in the Widesight project with a raytracing program he had developed for other purposes. We learned the hard way that there is a lack of available data: there are various eye models, the Gullstrand Eye for instance, but in raytracing there is a need for precise knowledge. If this is lacking, if you are forced to approximate, it is very noticeable, which is an advantage.

The Sven-Göran Pettersson program has now been stretched to its absolute limits. In Appendix 3, he provides a report of the data he has been using, his earliest results and his working methods. To this can be added that it was on his computer, using his program, that we achieved on October 28, 1997 the first optical system which provides a relatively decent image in peripheral vision,

We do not believe that it would be cost-effective to build a larger raytracing system on our own. Consequently, we are going forward along two alternative routes. One route involves searching out fellow researchers who are engaged in work similar to our own. The other involves looking for opportunities for using large commercial raytracing programs where we would introduce the eye as the object of study.

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The Tübingen programme

The Tübingen Program

While carrying out documentary research on raytracing, we found Wolfgang Fink, Tübingen. He presented his doctoral thesis entitled "Anwending theoretisch-physikalischer Methoden in der Ophtmalmologie" at Tübingen in 1997. A portion of his program is available to other researchers and students, and with Wolfgang's kind permission we are using his program via the Internet in a course being offered at CERTEC during the 1997 fall semester. It is an excellent teaching tool.

Even more importantly, Wolfgang accepted our invitation to spend October 27 and 28, 1997 with us in the Widesight project, sitting at a computer, comparing notes, generating ideas. The meeting resulted in Wolfgang agreeing to spend January and February of 1998 as a guest researcher with us, and at present extensive preparations are under way for his visit.

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Opera

Opera

Yes, this word is actually written on one of the Widesight branches. And the reason for this is definitely not that we wish to introduce the computer aid "Opera" for the partially-sighted in this context, but because we wish to use "Opera" as an umbrella term for the whole mass of large raytracing programs. We are introducing this generic term to highlight the aspect which they have in common: their predictability. "It is like going to the Opera", says Bodil. "If you are familiar with the story it is easy to follow, otherwise it isn't".. The situation is the same in raytracing programs. Not a single deflection of the rays will take place without somebody having introduced a deflecting member and having given it all its characteristics.

We are presently gaining experience of a large raytracing program by using the fascinating OSLO program. Jonas Sandsten, an engineer with the Department of Physics at the Lund Institute of Technology, has started a project where he utilizes his access to the system, his skills in handling it (these systems are large and require a very experienced designer and system optimizer), and his personal acquaintance with optics on a close family level.

We are very hopeful that, in the next six months, we will be able to show strong results for peripheral rays in a computer generated eye. But there are so many branches to this tree that we are not really able to control how they grow. So much the better. It may be the raytracing programs that will initiate trials with specific aids, but it may also turn out to be the case that the experience gained from trials will generate questions for the raytracing program: why is it like this?

In other words, we are looking forward with curiosity and a smile in all directions and with the insight that there is no end to the work awaiting us in this field

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2. Development of Measuring Methods

The Scotoma Lens Jenny

The Scotoma Lens Jenny

In projects where the ideas are as radical as the ones in PEER and Widesight, it is advantageous to be able to do a computer simulation first or to use oneself as a test subject before approaching blind or partially sighted people.

To simulate a central scotoma, Jörgen Gustafsson has invented the scotoma lens "Jenny". Simply put, it is a black contact lens which is applied to the eye in the same manner as regular contact lenses. A blockage in a ray path may either cause an area to become black, i.e. to be in a shadow (as is the case here) or, in other instances (for example, if you put a black patch over a large part of a camera or telescope lens) it may only make the image fainter.

Of course, if I, Bodil, put the scotoma lens Jenny in my eye, I will not experience the same thing as a person with a real central scotoma or loss of function in the macula of the retina. But I will perceive the black area and above all it will be possible to use me as patient and examine my peripheral vision.

Large scotoma lenses are required to make the effect obvious. With smaller lenses, for example a lens which covers the pupil for a given moment, the eye dilates, i.e. the pupil widens in order to take in more light and one can sometimes see an image, and sometimes not.

When I am wearing a Jenny lens, it is possible to examine separately my ability to utilize my peripheral vision. For example, it is possible to check, as we mentioned above, whether a positive correction is needed in peripheral vision.

Naturally, Jenny can also be an excellent tool for rehabilitation and health care professionals and relatives in helping them to get an idea of how a person suffering from scotoma sees the world. But that type of application is outside the scope of the Widesight project.

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Measuring Peripheral Vision

Measuring Peripheral Vision

The measuring of peripheral vision which has been carried out to date mainly consists of examinations of the visual field of individuals. Measuring is performed using light objects of various strengths in order to determine where in her field of vision a person can perceive a light stimulus. Several different types of equipment and methods have already been developed and more are being developed with considerable resources being invested for the purpose of studying the visual field as thoroughly as possible. Currently, SLO (Scanning Laser Ophthalmoscope) is the state of the art. This equipment makes it possible to assess different parts of the retina in a new and better way. Quite a considerable amount of research is being carried out using the SLO, which will likely result in a better understanding of different types of central scotoma and the possibility of using excentric fixation,etc.

There is, however, no equipment available for purely optical measuring of the refraction of light in the peripheral part of the retina. All equipment known to us is designed for measuring central rays. The methods commonly used today, such as auto-refraction, do not work if the eye is not fixed on a mark located straight ahead. The objective method skiascopy (retinoscopy) is impossible to use since the reflex that the examiner is to assess becomes very strange and impossible to interpret if the angle from the optical axis is greater than 10-15 degrees.

Consequently, "Widesight" is attempting to develop new methods of investigating the optical refraction of peripheral rays. We are following two paths in this work. One involves an exterior arrangement of a type different from the auto-refractor but with the same purpose of trying to measure refraction and reflection in peripheral vision. The other involves studying images in peripheral vision using a type of fundus camera.

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3. Development of Visual Aids

Optical Glasses for Widesight

Optical Glasses for Widesight

With the aid of the raytracing programs described above we are on our way to gaining an understanding of the kind of optics that peripheral vision might require. Perhaps we will start directly by testing glasses using computer simulations, perhaps the measuring equipment for peripheral rays will come first. But with the present state of our knowledge it is not obvious what should be considered testing as opposed to a finished visual device.

If/when the results begin to be generated, various teaching and training possibilities will also emerge. Perhaps receptors outside the macula area can be activated or trained so that a partially sighted person is better able to find her way about and/or read?

And , there will be additional areas of application, of course. From the point of view of evolution, human beings are not made to drive cars. Our ability to perceive signals from the side is not good enough. What if better optics for peripheral vision improves our ability to catch a glimpse of living warning signs such as a moose or a child running out into the street? In that case, everyone ought to have special driving glasses with an optical correction for peripheral vision. All we can say is that we are working on it.

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A New Type of Contact Lens

A New Type of Contact Lens

At present, it is difficult to tell whether glasses or contact lenses are best for correcting peripheral vision. It is reasonable to assume that contact lenses will be best - for those who wish to and are able to wear them. The reason for this is the same as the reason why, optically, contact lenses are better than glasses- they are placed close to and follow the movements of the eye.

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Electronic Glasses for Widesight

Electronic Glasses for Widesight

Increasingly, small LCD screens are being tested as devices worn on the head by people with visual impairments. In the United States, in particular, several trials are in progress, including the LVES as one example. From what we have seen so far, all these devices are awkward and cosmetically very noticeable.

However, where developments in this field are concerned, it would be impossible not to consider the possibilities of digital glasses. In principle, as soon as information is available in the form of ones and zeros it becomes easy to manipulate. As a matter of programming, it would be easy to change the magnification, color, contrast, intensity, even the position of the image (so that people with central scotoma will find reading easier), and individual adjustment would be possible.

If, subsequently, it became possible to create equipment which follows the movements of the eye - it would mean that we had really come a long way!

LVS, Low Vision Services and Erling Bergmark, are our partners in this branch of Widesight.

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