Download Definitions of Visual Impairment

Exceptional Children
An Introduction to Special Education
Tenth Edition
William L. Heward
© 2013, 2009, 2006, 2003, 2000
Pearson Education, Inc. All rights reserved.
Chapter 10
Blindness and Low Vision
Focus Questions
What are the instructional implications of the three general
classifications of visual impairments that educators use?
How do blindness and low vision affect learning, motor
development, and social interaction?
Why is it important that teachers know about the types of
visual impairments affecting children in their classroom?
How do the educational goals and instructional methods for
children with low vision differ from those for children who are
blind?
How might the educational placement of a student with visual
impairments affect her opportunities to learn the expanded
core curriculum of nonacademic skills necessary for overall
success in life?
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-2
Definitions of Visual Impairment
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 visual acuity is 20/70 in the better eye after
correction is considered partially sighted for legal purposes
IDEA definitions of visual impairments 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
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-3
Characteristics
Cognition and language
•
Impaired or absent vision makes it difficult to see the
connections between experiences
•
Abstract concepts, analogies, and idiomatic expressions can
be difficult to understand without sight
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
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-4
Factors Influencing Social
Involvement
•Several
factors influence the limited social involvement of
children with visual impairments
•Many
cannot benefit from peers or adult role model because of
the low incidence of the disability
•The
inability to see and respond to the social signals of others
reduces opportunities for reciprocal interactions
•Some
individuals with visual impairments engage in repetitive
body movements or other behaviors which places them at a
great social disadvantage
•Many
report the biggest difficulty socially is dealing with the
attitudes and behavior of sighted people
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-5
Prevalence and Causes
Fewer
than 2 children in 1000 have visual
impairments
Many
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
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-6
Educational Approaches
Braille is the primary means of literacy for people
who are blind
•Braille
is a tactile system of reading and writing composed of
raised dots
Tactile aids and Manipulative
Technological Aids for Reading Print
•
Kurzweil 1000 - Optical character-recognition system
•
Hardware/software that magnifies screen images
•
Speech recognition software
•
Software that converts text files to synthesized speech
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-7
Educational Approaches
Special Adaptations for Students with Low Vision
•
Functional vision teaches the use of remaining vision
Optical devices
•
•
•
•
Glasses and contact lenses
Handheld telescopes or magnifiers
Closed-circuit television systems
Augmented reality systems
Approaches for Reading Print
•
•
•
Approach magnification
Lenses
Large print
Classroom Adaptations
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-8
Expanded Core Curriculum
Orientation and mobility training (O&M)
•
Cane skills
•
Guide dogs
•
Sighted guides
•
Electronic travel aids
Listening skills
Functional life skills
•
Cooking
•
Personal hygiene
•
Shopping and financial management
•
Transportation
•
Recreational activities
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-9
Educational Placement
Alternatives
88% of children are educated in public schools
62% are members of general education classrooms
13% attend resource rooms for part of each day
•
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 a skilled and supportive
general education teacher
12% are served in separate classrooms
6% attend special day schools
4% attend residential schools
Heward
Exceptional Children, 10e
© 2013 Pearson Education, Inc. All rights reserved.
10-10