Module-8-VI - Visual Impairment PDF

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MODULE - Learners with Additional NeedsLearners with Difficulty SeeingINTRODUCTIONVision is perhaps the most important distance sense for interpreting theworld around us. It helps us to perceive and understand as to what is taking placearound us. It provides a continual feedback and a frame referenc...

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MODULE

- Learners with Additional Needs Learners with Difficulty Seeing

INTRODUCTION Vision is perhaps the most important distance sense for interpreting the world around us. It helps us to perceive and understand as to what is taking place around us. It provides a continual feedback and a frame reference for action. Eyes are one of the primary organs that are fully developed at birth. Visual abilities improve rapidly during the first years of life. For all of us, vision is the primary way we master skills for physical, psychosocial and cognitive aspects of self and environment. Vision is a distance sense, which provides information from outside our bodies. The term “visual impairment” is used as a generic term. Often other terms like blind and low vision are also used, depending on the nature and degree of loss, which in turn affects the individual in significant way like difficulty in mobility, access to printed information and independent living.

LEARNING OUTCOMES After working through this Module you should be able to : a. Define legal and educational blind; b. enumerate and describe the types and causes of the problems of the vision; c. enumerate and describe the assessment procedures in determining the cognitive ability, communication skills and socio-behavioral traits of student with problems in vision d. enumerate and describe the types of educational programs and instructional strategies for students with vision problems. e. gain inspiration from the abilities of person who are blind or have low vision

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A. ACTIVATE PRIOR KNOWLEDGE Close your eyes tightly for a few hours. Better still, cover them with an eye shade or a piece of back cloth so that you cannot see anything. Then walk around the house and look for familiar things that you use every day in the bedroom, bathroom and in the kitchen. Next, do the usual activities you engage in, such as cleaning the house, changing your clothes or taking a bath and preparing your meals. Write a report on your experiences as a person without sight.

B. Analysis After the activity, try to answer some guide questions for your report. - How well did you do your usual activities? - What problem did you meet? How did you solve them? - How did you feel about the whole experience?

C. Abstraction Blindness and Low Vision There are two general definitions of blindness. The first is the legal definition that is based on measurement of visual acuity, field of vision and peripheral vision. Visual Acuity - Visual acuity is the ability to clearly distinguish forms or discriminate details at a specific distance. Normal visual acuity is measured by reading letters, numbers and other symbols from a chart 20 feet away. The Snellen chart is commonly used for this purpose. The sizes of the letters in the chart correspond to the appropriate distances where they can be read with normal vision. Thus, when a person can read the row of letters marked 20/20 correctly, he or she has normal vision. His or her visual acuity is 20/20, that is, he or she can read the letters that normal vision permits to be read 20 feet away when seated 20 feet away from the chart. Field of Vision - The field of vision refers to the area that normal eyes cover above, below and on both sides when looking at an object or when gazing straight ahead. The field of normal vision covers

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approximately a range of 180 degrees. When looking directly at an objet, the central field of vision is used. Peripheral Vision - The peripheral vision covers the outer ranges of the field of vision. A person may have poor central vision but good peripheral vision. Tunnel vision results from an extremely restricted field of vision. It is like looking at the objects in the environment through a narrow tube or tunnel. The field of vision can decrease slowly undetected among children and adults over a period of years. A complete eye examination should include both visual acuity and field of vision. Legal Blindness Legal blindness refers to the condition where visual acuity is 20/200 in the better eye after the best possible correction with glasses or contact lenses. The field of vision, whether central or peripheral is limited to an area of 20 degrees or less from the normal 180-degree field. A legally blind person with his or her eye glasses or contact lenses on can see or read only at 20 feet objects and letters that those with normal vision can see or read 200 feet away. The person experiences difficulties in everyday activities especially in discerning fine details of objects and things in the environment. In the United States, persons who are legally blind are eligible to receive a wide range of benefits from the government. These include special education or vocational rehabilitation services, free mail service and income tax exemption.

Educational Definition Not all legally blind persons are totally blind. In total blindness the person is absolutely without sight but may have light and movement perception and travel vision. The degrees of blindness include light perception (person can differentiate between light and dark, day and night), movement perception (person can detect if an object or person is in motion or in still position) and travel vision (field of vision is enough to travel safely in familiar areas). Although classified as blind, the person can still use his or her residual vision. In special education, children who are blind are differentiated from those who have low vision. Blind children use their sense of touch to red Braille and train in orientation and mobility to move around and travel independently. A child with low vision learns to read materials in large print. Corn’s definition of low vision emphasizes the functional use of vision. Low vision is a level of vision that with standard correction hinders an individual in the visual planning and execution of tasks, but which permits enhancements of the functional vision through the use of optical or non optical aids and environmental modifications or techniques.

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TYPES AND CAUSES OF PROBLEMS OF VISION The inability of the eyes to function efficiently may be traced to: 1. errors of refraction - Hyperopia or Farsightedness -

Myopia or Nearsightedness

2. imbalance of the eye muscles Strabismus- different images are cast on each retina resulting to crosseyedness or squinting. Diplopia or Double Vision- results when the brain cannot fuse the differences in the images cast on the retina into a single image. Ambylopia- occurs when vision is suppressed in one eye and it becomes weak or useless. Nystagmus- is a condition in which there are rapid involuntary movements of the eyeball that can result to nausea, vomiting and dizziness. 3. diseases Diabetic Retinopathy- occurs when diabetes mellitus interferes with the flow of blood to the retina causing it to regenerate. Cataract- caused by the clouding of the lens which results to progressive blurring of vision and eventually blindness occurs. Macular degeneration is the leading cause of severe, irreversible vision loss in people over age 60. It occurs when the small central portion of the retina, known as the macula, deteriorates. The retina is the light-sensing nerve tissue at the back of the eye. Coloboma-is a degenerative disease in which the central and or peripheral areas of the retina are not completely formed. 4. trauma or accidents

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Impact of Vision Impairment and Blindness The learning processes of students with vision impairment may be affected in the following ways: •

Students with vision impairment may access information in a variety of ways, for example Braille, audio-tape, or enlarged print. Braille readers cannot skim read and may take up to three times as long as other students to read a text. Students with some vision may be large-print readers. Many will be unable to read examination questions and handouts in standard print or read their own handwriting when answering examination questions. They may also be unable to take their own notes. Extra time is needed to carry out some tasks, such as locating words in a text when shifting from one reading medium to another.

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Students who need information put into alternative formats must wait, often up to six to eight weeks, for the material to be produced for them. This means that they will often fall behind other students in the class.

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Students with vision impairment may feel isolated in the learning environment, which can have an impact on learning.

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Headaches often result from eyestrain. This may reduce considerably the study time available to these students.

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Participation and interaction in tutorials may be limited. It is difficult for students who cannot see the body language and interactions of others to feel comfortable about participating. Judging when it is appropriate to interrupt or to take a turn in discussion is particularly difficult.

Teaching Strategies There is a range of inclusive teaching and assessment strategies that can assist all students to learn but there are some specific strategies that are useful in teaching a group which includes students with vision impairment. We often take for granted the amount of visual information received every day. Many students with a vision impairment do not have a lifetime of visual experiences to draw upon. It may be necessary to consider the amount of assumed visual content in your subject when designing learning tasks. •

Prepare as much information as possible in electronic format - this makes it much easier to provide materials in accessible formats and allows users with disabilities to adapt the information to a format which is suitable for them.

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Make required book lists and course materials available early so there is sufficient time for them to be reproduced in audio or Braille, if required.

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Indicate compulsory texts in your reading list, noting important chapters if possible. Specifying the order of reading within a text is helpful, as it can take many weeks to have a book reproduced into audio or Braille.

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For students with vision impairment your teaching style will need to be ‘verbal’. Think about how to communicate information to students who cannot see what you are doing.

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Verbalise what is written on the blackboard and on PowerPoints. Talk through any calculations as they are made or procedures as they are carried out. Read any printed information and describe any charts or graphs being used.

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Academic activities which take place off-campus (such as industry visits, interviews or field work) may pose problems and on-campus alternatives may need to be considered.

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Provide an individual orientation to laboratory equipment or computers in order to minimize the anxiety likely in an unfamiliar environment.

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Consider supplementing laboratory practical’s, experiments or field trips, for example by audio taping commentaries.

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Inform the student if you plan to use videos, slides or PowerPoint, and discuss alternative ways of presenting the necessary information.

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Because students with vision impairment are generally slower than other students in completing reading tasks (reading is slower; considerable time is involved in getting material taped or Brailled), provide reading lists well before the start of a course so that reading can begin early. Consider tailoring reading lists and provide guidance to key texts.

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Providing the student with a vision impairment with prior notice that you plan to use a film or video in class allows him/her the option to request to see it beforehand. This will enable him/her to sit very close to the screen or have someone explain the film or video. It would be helpful to 'pause' on important points when the student is viewing the resource in class with others.

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A student may have difficulty finding his/her essay or assignment in a pigeonhole or amongst a pile of other students' work.

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Students may not be able to read your hand-written comments. It would be helpful if you could negotiate alternative feedback mechanisms with the student.

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Students are usually able to access online learning materials with the use of assistive technologies if websites follow accessible web design guidelines.

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The vision of some students may be affected by the glare from fluorescent lights or sunlight so you may need to attend to some aspects of your teaching environment. This should be done unobtrusively.

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Use tactile graphics where necessary

Assessment Strategies In considering alternative forms of assessment, equal opportunity not a guaranteed outcome, is the objective. You are not expected to lower standards to accommodate students with a disability, but rather are required to give them a reasonable opportunity to demonstrate what they have learned. Once you have a clear picture of how the disability impacts on learning, you can consider alternative assessment strategies: •

Students with a vision impairment may need particular adjustments to assessment tasks. Once you have a clear picture of how the disability impacts on learning you can consider alternative assessment strategies.

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Provide extensions to assignment deadlines if extensive reading has been set. Consider setting alternative assignments in which students have the

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opportunity to work intensively on a few selected texts rather than having to read widely. •

Examination papers may need to be enlarged or Brailled, with tactile diagrams, maps etc. It may be necessary to provide heavy line paper, a scribe or special writing implements.

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Some students may undertake examinations using a personal computer with assistive software. Some may need other assessment adjustments such as a reader/scribe, an oral examination, audio taped questions or large print papers. It may be necessary to provide extra space for equipment and specific personnel or a separate examination venue if the noise from equipment being used is likely to be distracting for other students.

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Provide extra time in examinations. Some students with vision impairment will require double time for examinations so time for rest breaks will be essential. Take-home examinations or split papers are a preferred option under such circumstances.

Tactile graphics People with a vision impairment are finding tactile graphics extremely valuable and, in some cases, vital for successful study, work and leisure. While people with a vision impairment are routinely provided with text transcribed into Braille, audio or large print, the pictures, diagrams and maps which accompany text are often omitted or only very briefly described. Visual graphics can effectively be converted into tactile graphics, even for the highly graphical information contained in maps and scientific material. This is not simply a matter of taking a visual image and making some kind of tactile photocopy – the tactile is a considerably less sensitive sense than the visual. Visual graphics need to be re-designed by experts, in a variety of formats such as vacuum-formed (thermoform), swell paper (microcapsule paper) and embossed (such as that produced on a Braille printer). They can also be accompanied by labels and descriptions in Braille or audio format. Tactile graphics are useful when: •

the user is print-impaired but has some tactual ability

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a concept not easily described in words

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a real object is unavailable for touching

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the shape, form or pattern is significant

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it is necessary to illustrate scale and explain maps, technology or biological relationships

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a one-time reference or reminder is needed

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the educational experience can be enhanced.

Tactile graphics are not, however, exact replicas of the original, nor are they good for fine detail and representing very large graphics. They should not be used without training and support materials. Colour Blindness Colour blindness (or colour deficiency) is typically a genetic condition, although it can also be the result of injury, disease or ageing. (Although not actually called colour blindness, age-related colour deficiency is a result of the yellowing of the corneas, which severely hampers the perception of violet and blue.) It is much more common in men than in women - around one in 12 men have some kind of colour perception problem. There are many different types and degrees of colour blindness. It is extremely rare to have monochromasy, the complete absence of any colour sensation

REFERENCES Inciong, T., Quijano, Y., Capulong, Y. & Gregorio, J. (2007). Introduction to Special Education. Quezon City: Rex Printing Press Company, Inc. Handbook in Special Education SPED Division Managing Children with Special Needs. A special Education Handbook Inciong, T., Quijano, Y., Capulong, Y. & Gregorio, J. (2007) K.Eileen Allen, G.E. Cowdery (2012). The Exceptional Child. Inclusion in Eary Chidhood Education. Wadsworth Cengage Learning

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https://www.adcet.edu.au/inclusive-teaching/specific-disabilities/blind-visionimpaired/ https://www.adcet.edu.au/resource/8830/accessible-physics-concepts-forblind-students-us/

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