Chapter 10 Blindness and Low Vision

1. Chapter 10Blindness and Low Vision

2. Definitions of Visual Impairment Legal definition of blindness • The legal definition is based on visual acuity and field of vision • A person whose visual acuity is 20/200 or less after the best possible correction with glasses or contact lenses is considered legally blind • A person whose vision is restricted to an area of 20 degrees or less is considered legally blind Educational definitions of visual impairments • The IDEA definition emphasizes the relationship between vision and learning • Totally blind: Receives no useful information through the sense of vision • Functionally blind: Learns primarily through the auditory and tactile senses • Low vision: Uses vision as a primary means of learning but may supplement by using tactile and auditory input

3. Characteristics of Students with Visual Impairments • Cognition and language • Impaired or absent vision makes it difficult to see the connections between experiences • Motor development and mobility • Visual impairment often leads to delays and deficits in motor development • Social adjustment and interaction • Children with visual impairments interact less and are often delayed in social skills • Many persons who have lost their sight report that the biggest difficulty socially is dealing with the attitudes and behavior of those around them

4. Prevalence and Causes • Fewer than 2 children in 1000 have visual impairments • Almost half of school age children with visual impairments also have another disability • Causes of visual impairments • Refractive errors: Myopia (nearsightedness) and hyperopia (farsightedness) • Structural impairments: Cataracts, glaucoma, nystagmus, strabismus • Cortical visual impairments: Suspected damage to parts of brain that interpret visual information

5. Educational Approaches • The age of onset has implications for how children with low vision should be taught • Visual impairment can be congenital (present at birth) or adventitious (acquired) Special adaptations for students who are blind • Braille (ex. 1) • Tactile aids and manipulatives • Technological Aids for Reading Print • Opticon - Optical-to-tactile converter • Kurzweil 1000 - Optical character-recognition system • Hardware/software that magnifies screen images • Speech recognition software • Software that converts text files to synthesized speech

6. Special Adaptations for Students with Low Vision • Functional vision • Teaching a child to use the vision that she has • Optical devices • Glasses or Contacts • Small hand-held telescopes • Magnifiers • Closed-circuit television • Reading Print (exercise 5) • Approach magnification • Lenses • Large print • Classroom adaptations • Special lamps • Desks with tilting tops • Off-white writing paper • Chairs with wheels

7. Expanded Curriculum Priorities • Orientation and mobility training (O&M) • Cane skills (ex. 4) • Guide dogs • Sighted guides • Electronic travel aids (ex. 2) • Listening skills • Functional life skills • Cooking • Personal hygiene • Shopping • Financial management • Transportation • Recreational activities

8. Educational Placement Alternatives 88% of children are educated in public schools • Itinerant teacher model • Most students who are included in general education classrooms receive support from itinerant teacher-consultants • The most important factor to the successful inclusion of students with visual impairments is the regular classroom teacher’s flexibility • Other important aspects • Peer acceptance and interaction • Availability of support personnel • Adequate access to special supplies and equipment • Residential schools • About 6% of school-age children with visual impairments attend residential schools