1. Chapter 10 Blindness 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 field of vision is restricted to an area of 20 degrees or less is considered legally blind (normal )
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 (light rays): Myopia (nearsightedness) and hyperopia (farsightedness)
Structural impairments (damage or poor development): Cataracts (cloudiness), glaucoma (high pressure), nystagmus (rapid back-forth movement), strabismus (both eyes cannot focus on same object)
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
Tactile aids and manipulatives
Technological Aids for Reading Print
Opticon - Optical-to-tactile converter
Kurzweil 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
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
Guide dogs
Sighted guides
Electronic travel aids
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