Blind Sight Published by THAMES & HUDSON Copyright Š 2007 David Jackson All Rights Reserved. This book may not be reproduced in whole or part, in any form (beyond that copying permitted by sections 107 and 108 of U.K Copyright Law and except by reviewers for the public press) without written permission from the publishers. ISBN 0-300-10347-6 Edited by Gillian D Jackson Designed by David Jackson Typeset by David Jackson Production and design supervised by Ian Parkin & James Corazzo Set in Baskerville and Swiss 721 BT Display Bold Printed by Mail Boxes Ltd on Brilliant White 150gsm Super matt Bound by The Cheshire Bindery, Cheshire Printed in Great Britain.
By David Jackson
I would like to offer my thanks to Henshaws Society For Blind People, Amy, Jackie, Maurice, David & Vicki.
Contents Introduction/8 Blind Sight/ 10 The Eye/12 Seeing/14 Eye care/16 Eye Testing/18 20/20 Vision/20 Test/22 Depth Perception/24 Eye Conditions/30 R.P/30 Nystagmus/32 Glaucoma/36 Cataracts/38 Retinal Detachment/40 ARMD/42 Blind Sufferers/44 Amy/44 Maurice/46 Jackie/50 Minds Eye/54 Dream Blind/58 Face Blind/66 Colour Blind/68 Stereotypes & Misconceptions/70 Light Perception/74 Colour perception/86 Mobility/88 Large Print/90 Braille/92 Conclusion/100
This book is an exploration and investigation into what it is to be Blind or Visually Impaired. The book is intended for all groups of readers. If you are sighted, then you cannot ponder the nature of being without due consideration for vision, and cannot contemplate the role of seeing in our lives without listening to the stories of those who are blind. The tales within this text are centred around the person as an individual, not just a blind or partially sighted individual. The information regarding blindness contained within this book is collected evidence, scientific study and real stories, It intends to inform and educate the reader of what it is to be blind. By reading this text I hope to change your understanding and perceptions of what it means to be Blind or Partially Sighted.
Understanding Visual Impairment
As the elderly population in developing nations grows exponentially, causes of age related vision loss as a result of macular degeneration, diabetic retinopathy, glaucoma and cataract are also growing dramatically. The world Health Organisation (WHO) estimates that there are forty-five million people world-wide who are blind, and three times this number who are visually impaired. In the United States, data indicate that one out of six adults fortyfive years of age and older self report vision that is not sufficient to read a newspaper or to see a friend’s face across a room, even when regular glasses are worn. Although exact prevalence data are difficult to obtain, WHO estimates that 1.5 million children are blind world-wide from cases such as cortical visual impairment, retinopathy of prematurity (ROP), optic nerve hypoplasia (ONH), corneal opacification resulting from xerophalmia and measles, severe malnutrition, congenital rubella, and maleria. Children with partial sight is at a number much higher than one would expect in todays world. Vision is considered to be the primary intergrating sense. We know that it plays an essential role in learning, with estimates showing that 80 percent of education is presented through the visual sense. Vision allows, at a distance, for the immediate preview and appreciation of an object’s position or layout of an enviroment. Vision constantly updates and unifies information and allows for the whole to be absorbed in almost an instant. Tactile exploration, aided by other senses, takes time and is available only in sequential pieces that must be organized and assorted mentally into a whole. Tactile information is enhanced by visual information. Vision serves as a motivator and guide for exploration, a source for verification of interaction with the environment and other persons, and a facillitator for the development of the ability to transfer information across other sensory-input systems. Vision is a complex sense with many components.
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Detail vision ( measured as visual acuity) is one of the most commonly known elements of vision. This is the vision we use for activities such as reading and seeing small objects and particular aspects of things. In a routine eye examination, the sharpness of this detail vision is measured for each eye and both eyes, and is compared with the norm of 20/20. A person’s vision may measure better than the norm (some people have visual acuity of 20/15). As the denominator of the acuity measurement gets larger, It expresses a worsening of vision. For example, 20/200 is the beginning of the relatively arbitrary category known as “Legal Blindness.” However, visual acuity alone does not tell very much about how a person sees or about the conditions under which that person functions best. Regular eye glasses or contact lenses and refractive surgery solve the problem for most people whose visual acuity is not within normal limits; they offset the imperfections in an individual’s eye by bending light rays to focus properly on the retina. However, many people, both young and old, experience vision that cannot be restored to normal even they have tried regular eyeglasses, medication, surgery, or some combination thereof. These people are said to have low vision. They will need a thorough assessment of their functional vision, prescription of specialized optical and adaptive devices, and mastery of techniques to compensate for this permanent, uncorrectable reduction of their vision.
Introduction
9
SEEING WHAT YOU DON’T SEE? Following certain kinds of brain lesions, patients report an inability to see objects, but if pressed to guess at their location they display a capacity to point at them with reasonable accuracy. The phenomenon, called “blindsight”, is one of the more dramatic of a number of lines of evidence suggesting that being aware of doing something is distinguishable from doing something, that areas of the brain underlying the experience of doing at least some things are distinct from those needed to actually do those things. Such a dissociation has a number of interesting implications. In a general sense, it provides evidence for the existence and significance of an “unconscious” as a contributor to human behaviour (and hence for “consciousness” as distinctive part rather than synonymous with the totality of brain function). Blindsight also provides a possible explanation for some experiences of “magical” or “transcendent” abilities, at least insofar as these relate to performance characteristics of individuals for which the individuals themselves cannot account. A dissociation between unconscious and conscious processing is also of significance in an educational context, since the two sorts of processing may acquire, process, and make use of experiences in different ways. Blindsight - the ability to respond appropriately to visual inputs while lacking the feeling of having seen them - might be something which only occurs in cases of brain damage, but seems much more likely to be a significant phenomenon of intact brain function as well. Indeed, it seems likely that blindsight (and similar phenomena in other spheres) is an important ingredient of a variety of activities where one wants to move quickly and appropriately, without “thinking about it”.
Blind Sight
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Blind Sight / Blind Sight
11
The
Understanding
eye Blind Sight
12
The individual components of the eye work in a manner similar to a camera. Each part plays a vital role in providing clear vision. So think of the eye as a camera with the cornea, behaving like a lens cover. As the eye’s main focusing element, the cornea takes widely diverging rays of light and bends them through the pupil, the dark, round opening in the center of the colored iris. The iris and pupil act like the aperture of a camera. Next in line is the lens which acts like the lens in a camera, helping to focus light to the back of the eye. Note that the lens is the part which becomes cloudy and is removed during cataract surgery to be replaced by an artificial implant nowadays.
Blind Sight / Colour
13
Observed Scene (Bethen Tower Manchester)
Seeing
Retinal Image of observed scene focused on the light-sensitive retina of the eye
Optic nerve
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Enlarged detail illustrating one possible type of ‘inner screen’ representation. Individual brain cells are shown as squares. The lighter the square, the more active that particular brain cell. Each brain cell is a symbol for one point in the observed scene, and its level of activity ‘codes’ the brightness of the point. The overall shape of the activity in the brain cells matches that of the scene: hence the photographic nature of the representation.
The Eye / Seeing
15
Windows to the soul Look after them! Close your eyes and finish reading this article, without peeking. Close your eyes and keep them closed while you go shopping, or dice onions, or shave. You can’t? No sighted person could. But these silly suggestions illustrate why we need to protect those most precious of gifts-our eyes. “Early detection of eye disease, so that it can be treated before irreparable damage occurs, is the best way to preserve eyesight” As we age, our eyes change, but that doesn’t mean that poor eyesight is inevitable. Poor eyesight results mostly from disease, and many of the most common eye diseases that afflict people over 50 can be prevented. This includes cataracts, glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD).
“Early detection of eye disease, so that it can be treated before irreparable damage occurs, is the best way to preserve eyesight”
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In 2001, the National Eye Institute (NEI), a division of the National Institutes of Health, funded a first-of-its kind study of eye disorders in Hispanics living in the United States. The results revealed glaucoma to be the leading cause of blindness among the group studied. The findings also revealed that women were more likely than men to suffer from vision impairment due to cataracts, glaucoma, and diabetic retinopathy. “The study underscores the need for early detection of eye disease among Hispanics,” said it’s author, Jorge M. Rodriguez, M.D., M.P.H., assistant research professor at the University of Arizona Department of Ophtha mology and Vision Correction. Early detection of eye disease, so that it can be treated before irreparable damage occurs, is the best way to preserve eyesight. And the best path to early detection is the path that leads to an ophthalmologist’s door. An ophthalmologist is a medical doctor specializing in diseases of the eye, and shouldn’t be confused with an optometrist. Optometrists are not necessarily medical doctors. Their main job is to measure eyes and fill prescriptions for eyeglasses, not to diagnose eye disease.
Blind Sight / Colour
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Testing
e ye
Blind Sight
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A regular eye test can help detect eye conditions before you notice the effect on your sight. Early treatment can often prevent your sight from getting worse. This leaflet explains what is normally included in a good eye test for adults (children may need different tests). A contact lens check is not the same as a full eye test. Contact lens wearers need regular eye tests as well as contact lens checks. Retinoscopy, This is one of the first tests to be performed in a comprehensive eye examination and it will give your optometrist an idea of what kind of prescription you may need. It gives a good starting point for the other tests. This is a photograph of an optometrist using a retinoscope, a small handheld instrument like a small torch, which bounces a light beam off the back of your eye and back into the instrument. She is focusing it onto a man’s eyes.
In a darkened room, you’ll be asked to stare at a target, such as a large letter E. The optometrist will shine a light into your eyes and will look at the way your eyes reflect light when different lenses are passed in front of them. Refraction, This test fine-tunes the prescription estimated by the retinoscopy. An instrument called a phoropter will be put in front of your eyes and you will be asked which of each choice of two lenses looks the clearer. Based on your answers, the optometrist will be able to determine which exact prescription is best for you. Refraction tells you how long-sighted, short-sighted, astigmatic or presbyopic you are. Visual acuity, The visual acuity test is the one most people think of when they think of an eye exam. You will be shown an eye chart and asked to say what’s on it. Adults are usually shown letters of the alphabet, while young children are often shown pictures.
Amsler grid, The Amsler grid is a pattern of lines in a square check formation, with a spot in the middle. While staring at the dot, you may notice variations in the regularity of the lines. This tests your central vision and can be used to detect the onset of age-related macular degeneration. This is a photograph of an optometrist getting a man to use the visual field screener. He is sitting in front of a machine a bit like a conical box. The top of the conical section has a whole in it to look through - and the man will see dots of light flashing onto a black background. Visual field, This test consists of lights flashing in the periphery of your vision while you stare at a light in the centre of your field of view. Also known as the perimetry test, it measures your peripheral vision and can be used to detect the onset of open-angle glaucoma.
The Eye / Eye Testing
19
02
20
Vision
Blind Sight
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By looking at lots of people, eye doctors have decided what a ‘normal’ human being should be able to see when standing 20 feet away from an eye chart. If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the “normal” human being can see. (In metric, the standard is 6 meters and it’s called 6/6 vision). In other words, if you have 20/20 vision your vision is “normal” a majority of people in the population can see what you see at 20 feet. From here on, please assume that the word normal has quotes around it. If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail. 20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States, this differs through the rest of the world. You can also have vision that is better than the norm. A person with 20/10 vision can see at 20 feet what a normal person can see when standing 10 feet away from the chart.
“If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the ‘normal’ human being can see.”
The Eye / 20/20 Vision
21
Blind Sight
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The Eye / Test
23
Blind Sight
24
Blind Sight / Colour
25
Depth perception is the visual ability to perceive the world in three dimensions. It is a trait common to many higher animals. Depth perception allows the beholder to accurately gauge the distance to an object. In modern terminology, stereopsis is depth perception from binocular vision through exploitation of parallax. Depth perception does indeed rely primarily on binocular vision, but it also uses many other monocular cues to form the final integrated perception. There are monocular cues that would be significant to a “one-eyed” person, and more complex inferred cues, that require both eyes to be perceiving stereo while the monocular cues are noted. This “third” group relies on processing within the brain of the person, as they see a full field of view with both eyes.
Blind Sight
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Depth Perception
27
Depth Indicators: A speculation Psychologists discuss several cues from which we gain impressions of depth. We used to think that these were indicators we had to learn to interpret, because, it was said, they lead to “inferences” about depth based on learned assumptions or beliefs. However, we now have abundant evidence that many of these “learned cues” and attendant beliefs are not learned. They provide information to infants of several species with little or no experience. The classic cues that may in fact be understood without training, and with just a little maturation in the normal environment, include several relevant to pictures: overlap or interposition, height in the visual field, linear perspective, and shading. The relation between these and tactile pictures is rarely considered. I wonder if there are serious and helpful implications here ripe for testing. Let me speculate that overlap, height in the field, and perspective all make sense to touch just as much to vision. Surely when blind infants realise through touch that a sock lying on a shoe and interposing between the laces and us is an overlap indicator, which tells us about depth. We also know that our feet are directly beneath us. But the sounds from, say, an approaching bicycle tyre on gravel can sound almost as if horizontal level-that is, the wheel on the gravelly ground is higher in direction to our feet. The sound directions are different, even though the feet and the tyre are actually level and on the same ground. This is a matter of perspective, and it is reflected all the time in blind people’s sense of the direction of things.
Blind Sight
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Depth Perception
29
Retinitus Pigmentosa Retinitus Pigmentosa (RP) is the name given to a group of hereditary eye disorders. These disorders affect the retina, which is the light sensitive tissue lining the back of the eye, in which the first stages of seeing take place. In RP, sight loss is gradual but progressive. It is unusual for people with RP to become totally blind as most retain some useful vision well into old age.
What causes RP? It is known that there are many different inherited defects causing RP. In all RP-related conditions however, the ability of the retina to respond to light is affected. The problem can be in many parts of the retina such as the rod or cone cells, in the connections between the cells of the retina.
What are the symptoms of RP? The most common first symptom is, difficulty in seeing in poor light conditions, for example outdoors at dusk, or in a dimly lit room. A second symptom is reduction of the visual field, in which sight is lost from the peripheral vision. This is often referred to as ‘Tunnel Vision’ and means that the rod cells, and some of the outer cone cells, have been affected first. In some RP-related conditions central vision is lost first. The first signs of this are difficulty in reading print or carrying out detailed work. All RP conditions are progressive, but the speed at which deterioration takes place varies from one person to another.
Blind Sight
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Eye Conditions/R.P
31
“Nystagmus is an involuntary movement of the eyes which is usually from side to side� What is Nystagmus?
Distorted Vision Distorted Vision Distorted Vision Distorted Vision Distorted Vision Distorted Vision Distorted Vision Distorted Vision Nystagmus
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Nystagmus is an involuntary movement of the eyes which is usually from side to side, however sometimes the eyes move up and down and in some cases the eyes may move in a circular motion. The majority of those with Nystagmus have vision which is significantly worse than average and well below what is considered to be short sighted. Many people can register as partially sighted and a minute number can be registered as blind. Nystagmus is not contagious or infectious. Nystagmus is not painful and it does not lead to total blindness. Vision seems to improve until it stabilises around the age of five or six.
What Types of Nystagmus are there? Nystagmus in early childhood may possibly be caused by a defect in the eye or visual pathway from the eye to the brain (the optic nerve). It occurs in a great range of eye disorders during childhood such as cataract, glaucoma, some disorders of the retina and albinism. Nystagmus may also occur in children who have multiple disabilities such as Down’s Syndrome. Several types of nystagmus can be inherited. To discover the chances of someone passing on nystagmus to the next generation a specialist must first make an accurate diagnosis of the underlying condition. It may then become necessary to consult a geneticist for detailed information and counselling. Acquired nystagmus which occurs later on in life may be a symptom of another condition such as a stroke, multiple sclerosis or even a blow on the head. There are many other causes of nystagmus. Nystagmus could be a sign of a more serious disorder of the eye or brain. Due to this fact it is vital that when nystagmus first develops in a child or adult they should be referred to an ophthalmologist (eye specialist) or a neurologist.
Eye Conditions/Nystagmus
33
Blind Sight
34
Blind Sight / Colour
35
Glaucoma is the name for a group of eye conditions in which the optic nerve is damaged at the point where it leaves the eye. This nerve carries information from the light sensitive layer in the eye, the retina, to the brain where it is perceived as a picture. Your eye needs a certain amount of pressure to keep the eyeball in shape so that it can work properly. In some people, the damage is caused by raised eye pressure. Others may have an eye pressure within normal limits but damage occurs because there is a weakness in the optic nerve. In most cases both factors are involved but to a varying extent. Eye pressure is largely independent of blood pressure.
What controls pressure in the eye?
Glaucoma
A layer of cells behind the iris (the coloured part of the eye) produces a watery fluid, called aqueous. The fluid passes through a hole in the centre of the iris (called the pupil) to leave the eye through tiny drainage channels. These are in the angle between the front of the eye (the cornea) an the iris and return the fluid to the bloodstream. Normally the fluid produced is balanced by the fluid draining out, but if it cannot escape, or too much is produced, then your eye pressure will raise.
Why can increased eye pressure be serious? If the optic nerve comes under too much pressure then it can be injured. How much damage there is will depend on how much pressure there is and how long it lasts, and whether there is a poor blood supply or other weakness of the optic nerve. A really high pressure will damage the optic nerve immediately. A lower level of pressure can cause damage more slowly, if left untreated a person could loose their vision because of this.
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“In some people, the damage is caused by raised eye pressure.”
Chronic Glaucoma The most common form of glaucoma is ‘Chronic Glaucoma’ in which aqueous fluid can get to the drainage channels (open angle) but they slowly become blocked over many years. The eye pressure raises very slowly and there is no pain to show that there is a problem, but the field of vision gradually becomes impaired.
Acute Glaucoma Acute Glaucoma is much less common in western countries. This happens when there is a sudden and more complete blockage to the flow of aqueous fluid to the eye. This is because a narrow ‘angle’ closes to prevent fluid from ever getting to the drainage canals. This can be a painful experience and will cause permanent damage to your sight if not treated promptly.
Eye Conditions/Glaucoma
37
A Cataract is a clouding of part of the eye called the lens. Your vision becomes blurred because the Cataract is like frosted glass, interfering with your sight. It is not a layer of skin that grows over your eye, despite what you may have heard. If your doctor or optometrist/optician has told you that you have a Cataract, don’t be alarmed. Many people over 60 have some Cataract and the vast majority can be treated successfully.
What is the function of the lens?
Cataracts “Your vision becomes
blurred because the Cataract is like frosted glass, interfering with your sight.””
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The lens is a clear tissue found behind the Iris, the coloured part of the eye. The lens helps to focus light on the retina at the back of the eye to form an image. To help produce a sharp image, the lens must be clear.
How does Cataract affect your sight? Blurry sight, This is a very common occurrence, you may notice that your sight has become blurred or misty, or that your glasses seem dirty of scratched. Dazzled by light, You may be dazzled by lights, such as car headlamps, and sunlight. Change of colour vision, Your colour vision may become washed out or faded. These eye problems may be a sign of other eye conditions. If you suffer from any of the above please see your optometrist or optician. Regular eye tests can catch any eye condition in the very early stages.
What causes a Cataract?
Treatment available
Cataracts can form at any age. The most common type of Cataracts is age related. These develop as people get older. In younger people Cataracts can result from conditions such as Diabetes, certain medications and other long-standing eye problems. Cataracts can also be present at birth. These are called congenital cataracts. Although researchers are learning more about Cataracts, no one knows for certain what causes them. There may be several causes including smoking, excessive exposure to sunlight or a poor diet.
The most effective treatment for Cataract is an operation to remove the cloudy lens. However, a good diet may help to slow the growth of age-related Cataract. In the past, eye specialists often waited until the Cataract became ‘ripe’ and your vision was very poor before suggesting you had the Cataract removed. Nowadays, with modern surgery the operation is usually done as soon as your eyesight interferes with your daily life. This includes having any difficulties with looking after yourself and others, cooking and driving.
Eye Conditions/Cataracts
39
Retinal Detachment
Blind Sight
40
Imagine that your eye is like a camera, and the retina is the film. The retina is a fine sheet of nerve tissue lining the inside of the eye. Rays of light enter the eye and are forced onto the retina by the lens. The retina produces a picture which is sent along the optic nerve for the brain to interpret. It is rather like the film in the camera being developed so that images can be produced.
What is Retinal Detachment? Retinal Detachments often develop in eyes with retinas weakened by a hole or tear. This allows fluid to seep underneath, weakening the attachment so that the retina becomes detachedrather like wallpaper peeling off a damp wall. When detached, the retina cannot compose a clear image from incoming rays and vision becomes blurred and dim. Who is at risk? Retinal Detachment is more frequent in middle aged, short sighted people. However, it is quite uncommon and only one person in ten thousand is affected. It is also extremely rare in children or young adults. Symptoms? The most common symptom is a shadow spreading across the vision of the eye. You may also experience bright flashes of light and/ or showers of dark spots called floaters. These symptoms are never painful. Many people experience flashers or floaters and these are not necessarily a cause for alarm. However, if they are severe and seem to get worse and you are losing vision, then you should seek medical advice. Prompt treatment can often minimise the damage to your eye.
Eye Conditions/Retinal Detachment
41
What are the different types of macular degeneration?
AGE
RELATED
MACULAR
DEGENERATION Blind Sight
42
What is age-related macular degeneration? Age-related macular degeneration (ARMD) is a very common cause of reduced vision in the UK. As the name suggests, it is a condition that tends to become more common as people get older. Although this condition may cause significant reduction in vision it never leads to complete blindness as it affects only the central part of the vision and the side, or peripheral, vision is always left intact. The retina, which is situated at the back of the eye, transmits the images that we see to the brain. The retina has two main parts - the macular and the peripheral retina. The macular is the part of the retina that is responsible for seeing fine detail, such as reading, seeing facial features and interpreting different colours. It is this part of the retina that is affected by age-related macular degeneration. How does ARMD develop? This is an ageing change and occurs because of ‘wear and tear’ changes in the macular region. It is thought that waste materials from this very active part of the eye build up as the mechanisms for removing them become less able. This causes damage to the cells over a period of time.
Who is at risk of age-related retinal degeneration? This condition tends to affect people who are over 60 years of age. Some younger people may be more susceptible, including people who are very short-sighted. Women tend to be affected more commonly than men, but that is probably because they live longer. There is a hereditary tendency, but this has not yet been fully researched.
There are two major types of ARMD. These are described as dry or wet. Dry ARMD; This is the more common form of ARMD and affects almost 80 per cent of those with the condition. The onset of this condition tends to be slow. Both eyes are usually affected symetrically. Wet ARMD; Wet macular degeneration is less common but tends to have a more severe and rapid effect on the central area of vision. In this condition, blood vessels from one layer at the back of the eye grow in an abnormal fashion into the macular area. These blood vessels may leak or bleed causing a rapid and significant reduction in central vision. This tends to affect one eye at a time but there is a risk of the same thing occurring in the other eye over the following months.
What are the symptoms of age-related retinal degeneration? Dry ARMD causes a gradual reduction in central vision. This tends to affect the ability to read and to see fine detail more than distance vision. The first symptoms of wet ARMD may be distortion of vision (known as metamorphopsia). This often has the effect of making straight lines appear curved or tilted. The vision deteriorates and eventually the central vision may be completely lost leaving a dark central area of poor vision (known as a central scotoma). This can also be referred to as black holes. Which treatments are available? There is research being carried out in this area but the treatments are far from universally successful. No tablets or drops are of any use in this condition. The vision tends to deteriorate gradually and the loss of vision is not always severe. Treatment involves wearing the best spectacles and possibly using bright lights to help you see things more clearly. The use of large print books and the prescription of a magnifying glass (low visual aid) are often necessary.
Eye Conditions/ARMD
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“Septo-Optic Dysplasia”
Amy is 22 years old and was born blind, due to the optic nerve in her left eye being smaller that it usually should be, leaving her totally blind in her left eye and partially sighted in her right eye. Her condition is called SOD and is a very rare eye condition. SOD is a highly variable condition which can characterised by changeable degrees of blindness, poor growth and low blood. Abnormal sleep patterns can also be associated with the condition. Amy is a HND Performing Arts & Media graduate and is shortly due to start work, after leaving Henshaws Blind Society. She has recently been for six job interviews, and feels she was unsuccessful due to her sight disability. I spoke with her at great length regarding how she feels about how blind people in general are treated by individuals and society as a whole. Amy is very independent and does not like people feeling they have to do everything for her. She feels the stereotype of a blind person is totally wrong as there are many varying degrees of blindness and not all blind people use a white cane, dark glasses and a guide dog. Travel and getting around in general are not a problem for Amy, she regularly travels by train to visit her grandmother in bury. Amy does not use her cane as often as she should, as she feels people stare at her whilst she is out in public. She feels there is a stigma connected to the white cane, and as a young woman it makes her feel uneasy whilst out shopping for clothes with friends. Amy’s attitude and acceptance of her condition is very impressive, she enjoys all things ‘normal’ sighted young people do. She has an active social life and also donates much of her time to helping fund raising for Henshaws Blind Society in Manchester.
Amy Blind Sight
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Blind Sight / Colour
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46
“We don’t all walk around looking like Roy Orbision, you know!”
Maurice Blind Sight
Maurice lost his sight two years ago, due to an accident where he lost a lot of blood, rendering him blind. He suffers from tunnel vision and is virtually blind in one eye. He described his sight to me, as having two toilet tubes to see through. All he can see is immediate objects in front of his eyes. He has no peripheral vision, which means he can no longer drive or work in his old job any more. Before his accident, Maurice worked as an engineer. He built aircraft wings amongst other things in Stockport. He did manual work as well as precise optical measurements for aircraft components, which required a keen eye. Due to the health and safety aspect involved in his job, Maurice had to leave his career as an engineer. He told me about using public transport, in particular the buses. Bus journeys are a major obstacle for Maurice as he trips up over peoples feet or items on the floor, which he can not see due to his condition. He does not use a white cane as he told me it is a flag for muggers, which I found shocking and also a good if not sad point for him to be aware of. Because he does not use a white cane, he told me that people treat him as if he is thick or mentally retarded, when he trips up over them or bangs into people in the street.
Blind Sight / Colour
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Maurice told me how before the accident he enjoyed walking in the park, but does not really get the opportunity now, as when in the park he can be walking down the path and a branch of a tree will hit him in the side of the head, due to him misjudging the distance. He told me about sets of eye condition simulation glasses, which Henshaws have that are made to simulate various eye conditions. Wearing the glasses could give me a greater sense of how people with various degrees of blindness view the world. I found Maurice to be a really nice bloke, and even though he is visually disabled he is learning to come to terms with his situation and hopes things will get easier for him with time. Blind Sight
48
Blind Sufferers/Maurice
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JACKIE Jackie lost her sight around 3 years ago. She began to notice her vision deteriorate whilst on a shopping trip with her daughter and grandchildren. After contacting her doctor and being referred to Manchester Eye Hospital Jackie learned that she had developed a condition known as Retinitus Pigmentosa, which means that she no longer has clear central vision. She explained it to me as having two spots in the centre of each eye, she can only see around those spots. Basically her peripheral vision has become her only way of seeing. Jackie’s grandchildren mean the world to her, it can be very upsetting for her as she has not seen them grow from three to six and five to eight. The only possible way she can partly see them, is to close one eye and lean in sideways. This is still not a clear picture and may be the cause of many headaches for her. This is due to straining her eyes.
Blind Sight
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Blind Sufferers/Jackie
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Blind Sight
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Blind Sight / Colour
53
A Mind’s Eye
Blind Sight
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“Blind and partially sighted people remember their surroundings by touching objects”
The phrase “mind’s eye” refers to the human ability for visual perception, imagination, visualisation, and memory, or, in other words, one’s ability to “see” things with the mind. The biological foundation of the mind’s eye is not fully understood. FMRI studies have shown that the lateral geniculate nucleus and the V1 area of the visual cortex are activated during mental imagery tasks. The visual pathway is not a one-way street. Higher areas of the brain can also send visual input back to neurons in lower areas of the visual cortex... As humans, we have the ability to see with the mind’s eye -to have a perceptual experience in the absence of visual input. For example, PET scans have shown that when subjects, seated in a room, imagine they are at their front door starting to walk either to the left or right, activation begins in the visual association cortex, the parietal cortex, and the prefrontal cortex all higher cognitive processing centres of the brain. The use of the phrase mind’s eye does not imply that there is a single or unitary place in the mind or brain where visual consciousness occurs. The phrase ‘A mind’s eye’ can also apply to blind and partially sighted individuals. As some blind people have no visual experience due to retinal detachment or what ever their condition, they see via their mind. For example if you close your eyes, and imagine your surroundings, you instantly know what objects are around you due to you previously seeing them and remembering visually where they are. This is similar to a blind persons perception (as difficult as that may be to imagine) as people with zero vision build a memory of their surroundings, not by sight, but by touch. Blind and partially sighted people remember their surroundings by touching objects, their brain documents these experiences and creates a memory of them. This process is not too dissimilar to that of sighted people, so in effect people with severe sight problems use their touch and memory to see. Mind’s Eye
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Blind Sight
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Mind’s Eye
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Do Blind people see in their dreams?
Dream Blind Blind Sight
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Dreaming is an overwhelmingly visual experience for sighted people. About half of all dreams also have auditory sensations, but in two large-scale studies less than one percent had gustatory, olfactory, or tactual sensory references (Snyder, 1970; Zadra, Nielsen, & Donderi, 1998). Kerr (1993) suggests that the extremely visual nature of dreams may be why many people wonder if blind people even dream. This wonderment may explain why the presence or absence of visual imagery in the dreams of the blind has been of scientific interest since the early nineteenth century. A series of questionnaire and interview studies since that time have led to four empirical generalizations: 1. There are no visual images in the dreams of those born without any ability to experience visual imagery in waking life. 2. Individuals who become blind before the age of five seldom experience visual imagery in their dreams, although Deutsch (1928) reports some visual imagery in six schoolchildren who lost their sight before age five. 3. Those who become sightless between the ages of five and seven may or may not retain some visual imagery. 4. Most people who lost their vision after age seven continue to experience at least some visual imagery, although its frequency and clarity often fade with time. Studies of blind participants in sleep laboratories using awakenings during REM periods to collect dream reports have shown results similar to the questionnaire and interview studies.
Despite recent advances in the understanding of sleep, dreams continue to bewitch us with their unfathomed mysteries. Dreaming occurs during paradoxical sleep, a stage in which people’s eyes move rapidly under the eyelids, and is therefore also known as rapid eye movement sleep. As we know from our own dreams, what we dream reflects our waking life experiences, which are mostly visual in nature. Are the content of visually impaired people’s dreams related to their lack of vision? Do they have visual images while dreaming? Indeed, how do visually impaired people dream?
The content of dreams Dreaming can be considered to be a passive event, a phenomenon that we experience but do not consciously control. When dreaming it can be said that we are mere onlookers of an unfolding drama. Nevertheless, some people claim to have “lucid” dreams - where they are aware of dreaming and are able to control the events of the dream. The content of a dream resembles what we experience in everyday life when we are awake. Usually, dreams are visual and mostly in colour (61%, but this proportion increases with longer dreams). Auditory and visual imageries are the most common sensations present in dreams (found in 76% and 100% of dreams respectively). External sounds can be incorporated, but on the odd occasion that dreamers speak of entirely auditory experiences, they tend to claim that they were not asleep at all. Other sensations, such as taste and smell, are not as common. Most dream settings are familiar, and most of the people that appear in dreams are known to the dreamer (apparently, celebrities crop up only rarely). So, if the content of dreams are a reflection of waking life, it follows that the dream content of people with physical conditions, such as visual handicap, must be related to their physical condition, in this case the absence of vision. Therefore, do visually impaired people who are afflicted from birth lack visual imagery and rapid eye movements in their dreams?
Dream Blind
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Blind Sight
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Dream content in the visually impaired
Visual imagery and dreams
People who are visually impaired from birth (congenitally visually impaired) seem to lack visual imagery and rapid eye movements in their dreams. The majority of the people who became visually impaired before they were aged 5 or 7 will have no visual dreams, but if sight is lost after the age of 7 visual imagery is retained in dreams into adulthood, with rapid eye movements present during sleep. With few exceptions, when visual handicap occurs between the critical ages of 5 and 7, visual imagery remains for varying periods of time, even in adulthood, and tends to get worse over time. Although it is thought that rapid eye movements are essential for visual dreams, it seems that many congenitally visually impaired people show eye movements during rapid eye movement sleep periods despite having no visual imagery. With the exception of the absence of vision, the dreams of those who became visually impaired before the age of 5 are no different in most aspects to those of the sighted, containing perceptions of sounds, touch, taste, smell, and temperature sensations (in decreasing order). As depicted in the example of a dream of a congenitally visually impaired person, heard speeches and conversations are prominent in visually impaired people’s dreams: “I was going up to heaven and St. Peter barred me at the gates, telling me to go down below. I argued with him, feeling I was being treated unjustly, until he said: ‘All your friends are down there’; whereupon I said, ‘If that’s the case it’s fine,’ and I went down below. It may seem surprising that taste and smell form such a minor part of dreams, given their importance to visually impaired people.
For most sighted people dream images are predominantly visual in nature. Visual imagery, however, is not the only means by which we can represent our surroundings. Just as when they are awake, visually impaired people can be conscious of their surrounding space while dreaming, through sensations other than touch. For example, a congenitally visually impaired person, dreaming that he or she is in a room, may be aware of the size and shape of the room, without describing, touching, or walking around in it. It is interesting that although visually impaired people may have different sensory experiences than sighted people they may express what they perceive using the same visual terminology as the sighted. The dream reports of visually impaired subjects can therefore be difficult to interpret. For the sighted, the visual component of imagery is its most noticeable feature, so it is difficult for those of us with sight to consider images and imagery without using visual metaphor or analogy. Yet much of the work that has been carried out on dreams of the visually impaired underlines the need for a broader definition of imagery - one that is not so strongly bound to the visual processing system.
Dream Blind
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Simultaneous Dreaming It is called simultaneous dreaming. This occurs when two or more people have the same dream. The dream need not occur at the same time to qualify as a simultaneous dream. But sometimes this happens too. There are no scientific studies of simultaneous dreaming. However, there are a few anecdotal reports of simultaneous dreaming on the internet. It is usually mentioned in relationship to lucid dreaming. Lucid dreaming is the conscious perception of one’s state while dreaming with the intended effect of having clearer dreams and to be able to control, focus, and utilise dreams to improve one’s life.
Blind Sight
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Blind Sight / Colour
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Blind Sight
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Blind Sight / Colour
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“They can see your eyes, your nose, your mouth, and still not recognize your face.”
Face Blind Blind Sight
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BILL CHOISSER WAS 48 when he first recognized himself. He was standing in his bathroom, looking in the mirror when it happened. A strand of hair fell down – he had been growing it out for the first time. The strand draped toward a nose. He understood that it was a nose, but then it hit him forcefully that it was his nose. He looked a little higher, stared into his own eyes, and saw ... himself. For most of his childhood, Choisser thought he was normal. He just assumed that nobody saw faces. But slowly, it dawned on him that he was different. Other people recognized their mothers on the street. He did not. During the 1970s, as a small-town lawyer in the Illinois Ozarks, he struggled to convince clients that he was competent even though he couldn’t find them in court. He never greeted the judges when he passed them on the street – everyone looked similarly blank to him – and he developed a reputation for arrogance. His father, also a lawyer, told him to pay more attention. His mother grew distant from him. He felt like he lived in a ghost world. Not being able to see his own face left him feeling hollow. One day in 1979, he quit, left town, and set out to find a better way of being in the world. At 32, he headed west and landed a job as a number cruncher at a construction firm in San Francisco. The job isolated him – he spent his days staring at formulas – but that was a good thing: He didn’t have to talk to people much. With 1,500 miles between him and southern Illinois, he felt a measure of freedom. He started to wear colourful bandannas, and he let his hair grow. When it got long enough, he found that it helped him see himself. Before that, he’d had to deduce his presence: I’m the only one in the room, so that must be me in the mirror. Now that he had long hair and a wild-looking scarf on his head, he could recognize his image. He felt the beginnings of an identity. Blind Sight / Colour
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Colour Blindness
Colour blindness (colour vision deficiency) is a condition in which certain colours cannot be distinguished, and is most commonly due to an inherited condition. Red/Green colour blindness is by far the most common form, about 99%, and causes problems in distinguishing reds and greens. Another colour deficiency Blue/ Yellow also exists, but is rare and there is no commonly available test for it. Depending on just which figures you believe, colour blindness seems to occur in about 8% - 12% of males of European origin and about one-half of 1% of females. I did not find any figures for frequency in other races. Total colour blindness (seeing in only shades of gray) is extremely rare. There is no treatment for colour blindness, nor is it usually the cause of any significant disability. However, it can be very frustrating for individuals affected by it. Those who are not colour blind seem to have the misconception that colour blindness means that a colour blind person sees only in black and white or shades of gray. While this sort of condition is possible, it is extremely rare. Being colour blind does keep one from performing certain jobs and makes others difficult.
Blind Sight
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Blind Sight / Colour
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“ Blind Sight
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We don’t have extrasensory powers like Superman”
The public holds two beliefs about blindness that seem to be mutually exclusive. One is the idea that blind people are generally helpless and incompetent. This belief is prevalent, as evidenced by an unemployment rate among blind people that stubbornly remains at around 70 percent. But coexisting with this view is the seemingly incongruous conviction that the blind are endowed with almost superhuman abilities. This belief arises from the myth that, when a person has lost one sense, the remaining ones become sharper to compensate for the lost sense--in this case eyesight. Thus the blind are believed to hear better than the sighted, which accounts for the musical talents of famous blind musicians like Ray Charles, Stevie Wonder, and Ronnie Milsap. It is also often assumed that the blind must naturally have extra-sensitive touch in order to read Braille. Of course neither of these beliefs is accurate. The blind are not helpless and incompetent, at least not when we have acquired effective training in the alternative techniques of blindness. Nor are we superhuman; we have simply trained ourselves to use our remaining senses in ways and with an attention that the sighted do not usually employ. Our hearing is not sharper, but we are likely to notice sounds that the sighted tune out because they deem them unimportant, like traffic noise or the sound of an air conditioning unit at a building we pass on our way to the store that serves as a clue to where we are on the route. The fact that we are able to read Braille proficiently comes from practice and training, not from magically altered nerve cells in our fingers. But though the public’s belief in the uncanny perceptual abilities of the blind provides little in the way of practical improvement to our lives--more job opportunities, greater social acceptance, and the like--it persists, and when the notion seems to be validated by a blind person, the media pounce on the story.
Stereotypes & Misconceptions
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Blind Sight
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Blind Sight / Colour
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LIGHT Perception Blind Sight
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Various scales have been developed to describe the extent of vision loss and define “blindness.” Total blindness is the complete lack of form and light perception and is clinically recorded as “NLP,” an abbreviation for “no light perception.” Blindness is frequently used to describe severe visual impairment with residual vision. In order to determine which people may need special assistance because of their visual disabilities, various governmental jurisdictions have formulated more complex definitions referred to as legal blindness. In North America and most of Europe, legal blindness is defined as visual acuity (vision) of 20/200 (6/60) or less in the better eye with best correction possible. This means that a legally blind individual would have to stand 20 feet from an object to see it with the same degree of clarity as a normally sighted person could from 200 feet. In many areas, people with average acuity who nonetheless have a visual field of less than 20 degrees (the norm being 180 degrees) are also classified as being legally blind. Approximately ten percent of those deemed legally blind, by any measure, have no vision. The rest have some vision, from light perception alone to relatively good acuity. Low vision is sometimes used to describe visual acuities from 20/70 to 20/200. By the 10th Revision of the WHO International Statistical Classification of Diseases, Injuries and Causes of Death, low vision is defined as visual acuity of less than 6/18, but equal to or better than 3/60, or corresponding visual field loss to less than 20 degrees, in the better eye with best possible correction. Blindness is defined as visual acuity of less than 3/60, or corresponding visual field loss to less than 10 degrees, in the better eye with best possible correction.
“Total blindness is the complete lack of form and light perception and is clinically recorded as “NLP,”
Light Perception
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Blind Sight
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Light Perception
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Blind Sight
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Blind Sight / Colour
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The concept of LIGHT is applied to stimuli that affect the sense of vision, i.e., it allows us to see things! A more inclusive definition includes any radiation, which shares with visible light many of the properties such as reflection, refraction, polarization, diffraction and velocity, e.g., ultra-violet and infra-red “light� which are of course invisible to humans.
Blind Sight
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Light Perception
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Blind Sight
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Blind Sight / Colour
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Blind Sight
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Light Perception
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Colour perception & Field Of Vision
Blind Sight
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Colour perception & Field of vision Diminished colour perception may result from some visual impairments, due to maldevelopment or damage to the colour receptor cells of the eye. There is an even larger number of people in the otherwise normally sighted population who are born with colour vision deficits. Between the congenital colour deficiencies and those acquired with eye diseases, there are some thirty-five million people in the United States alone with a reduced ability to distinguish colours. This can be an obstacle when colour discrimination is an important recognition feature for a learning experience. Contrast sensitivity is another fact of the way we see. The ability to distinguish an object, letter, or shape for example, from the background against which it is placed is important to vision and to many daily activities. Contrast discrimination may be poor because of certain diseases and may result in an impaired ability to discern steps, and signs, symbols, or other things that may be of similar colour to the background. A person may notice a qualitive diminution of vision when contrast sensitivity worsens, even when visual acuity remains the same. Glare sensitivity provides additional insight into how we see. Although the human visual system needs light to function optimally, certain vision conditions can produce extreme difficulty in handling excess light. Indoors in brightly lit rooms, or when there is reflected glare from television screen, monitor, or unshielded window, or outdoors on excessively bright or glary days, some people may experience severe impairment of their ability to function. Visual field is the term used to describe what a person sees side to side and above and below when looking straight ahead. This side peripheral, vision is extremely important to a persons ability to gather enough visual information to do things such as getting around safely, locating a seat, seeing an entire stage in a theatre, and so on. Some vision-impairing conditions result in a loss of peripheral vision (‘tunnel vision�) or in a loss of part of the field of vision. The person experiencing this type of visual impairment often must learn to use compulsory strategies like turning the head to scan or using a mobility cane in order to acquire the information they need to do things safely.
Light Perception/Colour Perception
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Getting from A to B can be a complicated and some what daunting task for blind or partially sighted people. As there are many obstacles and unfamiliar surroundings for them to contend with. A minority of blind and partially sighted suffers will not venture outside unless they are accompanied by someone to help them about. This is not true for the majority thought, most live very active lives and treat getting around as just another part of having a sight problem. They generally plan their journeys ahead, to make things easier, by planning the journey they can plan for any problems which may arise, such as public transport.
A
Travel Tips For People Who Are Blind or Visually Impaired
B Blind Sight
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Plan ahead. Read about your destination before your trip so you know what to expect and what sights you’ll want to visit. Make reservations whenever possible. Call airports and airlines ahead of time to find out about services, including seating arrangements, special meals and shuttle services. Carry written directions with you. Have directions written down before leaving. Even if you can’t read them you can ask for help by showing them to someone else if you get lost. It’s also helpful to have a copy of the exact address of where you are going. A driver may not know where a specific hotel is, especially if there are several with the same name. Keep necessities with you at all times. Carry your money, keys, tickets and bus pass in a pocket. If you happen to misplace your purse or wallet or someone takes it, you still can reach your destination. Keep some extra money handy for tips. Know the bus schedule. Inform the bus driver where you want to get off so he knows to call it out. Sit near the front of the bus. Notify others about your needs. Inform your travel agency or companies such as airlines you are using that you are visually impaired. Tell your companion or those around you about your visual limitations. Ask questions. If you cannot see a monitor or find a gate at the airport or bus station, ask a customer service representative or another traveller to help you find your way. Carry your cane. Whether you choose to use it or not for mobility purposes, your cane helps to notify others that you are visually impaired. Ask about amusement park or other tourist discounts. Some of the amusement parks give discounts either to visually impaired visitors or to their sighted guides. Preboard and bring carry-on luggage. Avoid the hassle of crowds and obstacles in aisles by preboarding trains and planes.
Mobility
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Large Print For many blind and partially sighted people reading is a problematic affair. Most blind people can still read regular size printed material such as Books, Newspapers, Magazines, etc. A general guide to type size for blind and partially sighted individuals is 18 point, which can in some cases, still be too small, depending on the readers vision. Clear print is a design approach which considers the needs of people with sight problems. This programme takes into consideration the needs of people with sight problems, this allows people to learn and enjoy reading again. It can be very frustrating for blind and partially sighted people, as most books in print do not always cater for their needs..
Blind Sight
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Large Print
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Braille Blind Sight
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Blind Sight / Colour
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What is Braille? Braille is a series of raised dots that can be read with the fingers by people who are blind or whose eyesight is not sufficient for reading printed material. Teachers, parents, and others who are not visually impaired ordinarily read Braille with their eyes. Braille is not a language. Rather, it is a code by which languages such as English or Spanish may be written and read.
What Does Braille Look Like? Braille symbols are formed within units of space known as Braille cells. A full Braille cell consists of six raised dots arranged in two parallel rows each having three dots. The dot positions are identified by numbers from one through six. Sixty-four combinations are possible using one or more of these six dots. A single cell can be used to represent an alphabet letter, number, punctuation mark, or even a whole word. The enclosed Braille alphabet and numbers card illustrates what a cell looks like and how each dot is numbered.
How Was Braille Invented? Louis Braille was born in Coupvray, France, on January 4, 1809. He attended the National Institute for Blind Youth in Paris, France, as a student. While attending the Institute, Braille yearned for more books to read. He experimented with ways to make an alphabet that was easy to read with the fingertips. The writing system he invented, at age fifteen, evolved from the tactile “Ecriture Nocturne� (night writing) code invented by Charles Barbier for sending military messages that could be read on the battlefield at night, without light.
How Is Braille Written? When every letter of every word is expressed in Braille, it is referred to as Grade 1 Braille. Very few books or other reading material are transcribed in Grade 1 Braille. However, many newly blinded adults find this useful for labelling personal or kitchen items. Blind Sight
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Braille
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Blind Sight
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Blind Sight / Colour
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Braille
Blind Sight
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The system used for reproducing most textbooks and publications is known as Grade 2 Braille. In this system cells are used individually or in combination with others to form a variety of contractions or whole words. There are 189 different letter contractions and 76 short-form words used in Grade 2 Braille. These “short cuts” are used to reduce the volume of paper needed for reproducing books in Braille and to make the reading process easier. Grade 1 (or uncontracted) Braille has nothing to do with first grade. Most children learn grade 2 (contracted) Braille from kindergarten on. In recent years, some teachers have chosen to begin teaching grade 1 Braille first, transitioning to grade 2 Braille by the mid-elementary years. There is currently no research that supports the superiority of one approach over the other. Just as printed matter can be produced with a paper and pencil, typewriter, or printer, Braille can also be written in several ways. The Braille equivalent of paper and pencil is the slate and stylus. This consists of a slate or template with evenly spaced depressions for the dots of Braille cells, and a stylus for creating the individual Braille dots. With paper placed in the slate, tactile dots are made by pushing the pointed end of the stylus into the paper over the depressions. The paper bulges on its reverse side forming “dots.” Because of their portability, the slate and stylus are especially helpful for taking notes during lectures and for labeling such things as file folders. Braille is also produced by a machine known as a braillewriter. Unlike a typewriter which has more than fifty keys, the braillewriter has only six keys and a space bar. These keys are numbered to correspond with the six dots of a Braille cell. In that most Braille symbols contain more than a single dot, all or any of the braillewriter keys can be pushed at the same time. Technological developments in the computer industry have provided and continue to expand additional avenues of literacy for Braille users. Software programs and portable electronic Braille notetakers allow users to save and edit their writing, have it displayed back to them either verbally or tactually, and produce a hard copy via a desktop computer-driven Braille embosser. Since its development in France by Louis Braille in the latter part of the nineteenth century, Braille has become not only an effective means of communication, but also a proven avenue for achieving and enhancing literacy for people who are blind or have significant vision loss.
Braille
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The context of this book has attempted to document the world of the Blind and Partially Sighted. Hopefully it has succeeded, and you have gained a greater insight and understanding of Blindness. My experiences of meeting and speaking to those with impaired vision or total sight loss has encouraged me to think of their disability on another level, and has dispelled my common misconceptions of blind people simply seeing blackness, walking with a white cane and wearing dark glasses.
Blind Sight
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Conclusion
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Blind Sight