1 / 49

Vision Loss

Teaching Students who are Blind or Visually Impaired in the Classroom -adapted from J. Northcott Aug./10. Vision Loss. 80 – 85% of what people know is learned through vision. Vision loss has an impact on learning and development. Congenital - Adventitious.

delu
Download Presentation

Vision Loss

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Teaching Students who are Blind or Visually Impaired in the Classroom-adapted from J. Northcott Aug./10

  2. Vision Loss • 80 – 85% of what people know is learned through vision. • Vision loss has an impact on learning and development.

  3. Congenital - Adventitious • Congenital visual impairments are a result of eye conditions that are present at birth. • Adventitious visual impairments are those that occur later in life as a result of illness or accident.

  4. Visual Acuity Levels • Normal Vision (between 20/12 and 20/25) • Near Normal Visions (between 20/30 and 20/60) • Moderate Low Vision (between 20/70 and 20/160) • Severe Low Vision (between 20/200 and 20/400) • Profound Low Vision (20/500 and 20/1000) • Near Blindness (Light Perception) • Total Blindness (No Light Perception)

  5. What is low vision? • A person has low vision if the visual acuity in his or her better eye is between 20/70 and 20/200, with the best possible correction.

  6. Low Vision – Legally Blind • A person is legally blind if his or her visual acuity is 20/200 or worse in the better eye with the best possible correction. • A person is legally blind if his or her visual field is 20° or less in the better eye.

  7. Visual Difficulties • Loss of Visual Acuity • Loss of Visual Fields • Reduced Contrast Sensitivity • Colour Blindness • Oculomotor Problems • Visual Processing Problems • Fluctuating Functional Vision

  8. Normal Visual Acuity

  9. Decreased Visual Acuity

  10. Decreased Visual Acuity

  11. Low Vision – Legally Blind • Individuals with low vision usually read large print, or regular print with visual aids. • Some individuals who are legally blind may use a combination of braille, large print, and low vision devices.

  12. Decreased Visual Acuity Common disorders associated with visual acuity loss: • Degenerative myopia • Cataracts • Retinal detachments • Retinopathy of prematurity (ROP) • Glaucoma • Underdeveloped eyes such as microphthalmia and optic nerve hypoplasia • Optic nerve atrophy • Albinism • Aniridia • Nystagmus

  13. Decreased Field of Vision • An individual with a visual field loss is limited in how large an area he or she can see. • Individuals often do not look at an object directly (eccentric viewing). • A person is legally blind if their visual field is 20° or less in the better eye.

  14. Loss of Central Vision

  15. Loss of Peripheral Vision

  16. BLIND SPOTS or SCOTOMAS

  17. Hemianopsia

  18. Decreased Field of Vision Common disorders associated with visual field loss: • Macular degeneration • Retinitis pigmentosa • Retinal detachments • Retinopathy of prematurity – ROP • Glaucoma • Hemianopsia • Colobomas • Optic nerve atrophy • Optic nerve hypoplasia

  19. Reduced Contrast Sensitivity • A simulation of loss of contrast sensitivity. Many low vision defects involve a loss of both acuity and contrast sensitivity.

  20. Colour Blindness • Most colour perception defects involve red, green or both. • Achromatopsia Students with Achromatopsia see the world in shades of grey. School work is frequently color coded. -control light and glare.

  21. Oculomotor Problems • Characterized by difficulty with coordinated movements of the eyes • One or both eyes may turn in (esotropia) or out (exotropia) • May result in difficulties following fast moving objects or accurately reaching for objects • May result in double vision or loss of depth perception • Strabismus, Amblyopia and Ocular Motor Apraxia

  22. Problems with Visual Processing • This eye condition associated with this is: Cortical Visual Impairment • Eyes are generally healthy and normal • Damage is to the visual cortex – difficulty in processing information sent to it from the eyes • Not the same as visual perceptual difficulties

  23. Expanded Core Curriculum Consists of 9 disability-specific skills … • Compensatory or Functional Academic Skills • Orientation and Mobility • Social Interaction Skills • Independent Living Skills and Personal Management skills • Recreation and Leisure Skills • Career and Life Management Skills • Assistive Technology • Visual Efficiency skills • Self-Determination

  24. Low Vision

  25. Things To Remember • No two individuals with the same eye condition will function visually in exactly the same way. • The majority of individuals with low vision will have fluctuations in visual functioning from day to day and situation to situation. • Physical and mental health factors such as medications, seizure activity, fatigue, etc. and environmental factors such as lighting, seating, contrast, etc. will affect an individual’s visual functioning.

  26. What Can We Do? • Environmental adaptations • Material adaptations • Teaching strategies

  27. Seating • Optimal seating • Consider student’s visual acuity • Consider student’s field of vision • Consult the teacher of the visually impaired

  28. Lighting • Appropriate lighting • Students should be seated so that they are not facing a window to reduce glare • Time may be needed to adjust to changes in lighting conditions • Consult the teacher of the visually impaired

  29. Lighting: Glare • Many students are sensitive to glare. • Reduce glare by: -colour contrast of reading materials -use non-glare lamination -adjust blinds in the classroom

  30. Contrast In The Environment Often contrast is as important, if not more important, than the size of print.

  31. Contrast In The Environment • Things to try: • contrasting coloured cloth, a coloured tray or a place mat to define work areas • using coloured electrical or coloured tape to mark the top of the volleyball net, court markings in the gym, a stripe on a drinking glass, etc. • using brightly coloured pylons for court markings, pinnies to help identify team members, and brightly coloured balls and shuttlecocks in PE

  32. Contrast In Learning Materials • Black boards: white or yellow chalk • White boards: black dry erase markers • Print materials: black print on white or yellow paper • Font: plain bold font such as Arial, Verdana, or Tahoma with 1 1/2 line spacing

  33. Large Print • 18 font is the standard font size for large print • Arial • Tahoma • Veranda • Maiandra • Times New Roman • Important to consider the size of print the student requires to access information • 140% enlargement on a photocopier of 12 point font provides enlargement to 18 point print.

  34. Organization – the Classroom • Alert student to any physical changes in the room • Doors or cupboards should be either closed or open all the way • Student may require extra space for all his/her materials

  35. Organization – the Teacher • Provide lists of novels, research topics, worksheets, readings etc. as soon as possible to the teacher of the visually impaired and/or education assistant

  36. Organization – the Student • Ongoing development of personal organization may be required. • Consider: -put away materials, worksheets, etc. right after they are finished with them -develop a filing system -develop folders on the computer and/or braille electronic notetaker to organize files

  37. General Strategies • Students may be missing background information • Do not avoid the use of words “look” and “see” • Visual fatigue may impact student’s functional vision • Address the student by name • Information from facial expressions or body language may be missed • May require extra time for exams and assignments • Provide feedback to the student in the same way that you would other students • Consider reviewing school fire drill prodedures

  38. General Strategies Near Tasks: • materials should be clear against a simple background – good contrast • use appropriate print size • avoid clutter • keep maps and diagrams simple

  39. General Strategies Distance Tasks: • allow student to move within the class to see boards, charts, etc. • read out loud as items are written on boards, charts, etc. • provide a large print or braille copies of notes

  40. SSVI - LRC Specialized Services for the Visually Impaired (SSVI) • 12360 – 142 Street N.W. • Edmonton, Alberta T5L 4X9 • Fax: 780-427-6683 • Toll free calls – use Government RITE system. Dial 310-0000 and then dial 780-427-4681. • www.lrc.learning.gov.ab.ca and click on Specialized Services for Students with Visual Impairments

  41. Helpful Low Tech Tools … • 20/20 pens • Bold lined writing paper and/or scribblers • Highlighter pens • Colored glue sticks • Line markers • Templates

  42. Assistive Technology: Low Tech

  43. Assistive Technology: Low Tech

  44. Physical Education

  45. Physical Education

  46. Games

  47. Guiding Documents • Alberta Education’s Standards for Special Education http://education.alberta.ca/admin/special/legislation.aspx • Essential Components of Educational Programming for Students who are Blind or Visually Impaired education.alberta.ca/media/511690/ecep_blind_or_visually_impaired.pdf • Canadian National Standards for the Education of Children and Youth who are Blind or Visually Impaired, Including those with Additional Disabilities www.apsea.ca/Cdn_Nat_Stands.pdf

  48. … something to think about If students floated in life jackets for 12 years, would they be expected to swim if the jackets were suddenly jerked away? The situation is similar for students receiving vision services. All too often these students are not taught how to self-manage their own lives before they are thrust into the cold water of post-high school reality. - Martin, 1993

  49. In closing Students who are blind or visually impaired deserve “the opportunity to be equal and the right to be different.” Dr. Phil Hatlen

More Related