Visual Impairments Chapter 16 by pharmphresh28


									Visual Impairments Chapter 16


IDEA….impairment in vision that, even with correction adversely affects a child’s
educational performance. Includes both partial sight and blindness.

Legal Blindness - refers to individuals whose central visual acuity, when
measured in both eyes and when wearing corrective lenses, is 20/200.

Tunnel vision sees less than 20 degrees field of vision, even if acuity is normal
(160 is normal)

Low vision describes individuals who can generally read print, many need optical

Functionally blind. Describes individuals who typically use Braille for efficient
reading and writing

Totally blind: describes individuals who do not receive meaningful input through
visual sense.


The population of students with visual impairments is heterogeneous

They different from each other in how they learn & in their visual functioning

Also, socioeconomic status

Parenting style

Cultural background

Age of onset of visual impairments

Presence of other disabilities

Some are gifted or have special talents

Large number have sever and multiple disabilities

Common characteristic that is more important in that they have limited ability to
learn incidentally from the environment
Limitations in range and variety of experiences

Limitations in experiencing the world meaningfully and safely from a distance

Experience different social interactions b/c of difficulty sharing common
experiences with sighted friends

Potential for inadequate development of social skills and related negative impact
on self esteem

Career development can be limited

Limitations in the ability to get around

Spontaneous ability to move around safely in environment (motor development,
knowledge base, social development)

Movement through space, limited opportunities for experiences. (may become
more passive)

Limitations in interacting with the environment

Limited visual reduces their level of readily acquired information about their
environment and their ability to act on that information.

They may not adequately inform themselves about the effect of their actions on
people and things around them

With young children, reduces vision correlates with poor motivation, to move
through the environment, manipulate toys and initiate interactions. Can have
long-lasting consequences

Visual impairments can result in experiential and environmental deprivation.

Causes of Visual Impairments

Damage to the structures involved in the visual process can be the result of an
event that happens during development of embryo, immediately after an infant’s
birth, can result from an injury or disease.

Congenital visual impairment occurs before birth or in the case of blindness,
before visual memories have been established

Students who acquire a visual loss after having normal vision have an
adventitious visual impairment

1 to 2 students in 1000 have a visual disorder that interferes with learning.

Determining the Presence

A students with Visual Impairment (VI) receives a nondiscriminatory evaluation

Medical specialist usually determines the presence of the disorder;

Educators need to know the cause of a student’s VI b/c there are typical
characteristics associated with particular eye conditions.

Functional Vision Assessment (FVA)

When educators work with the student and family to determine the effects of the
disorder on the student’s visual functioning.

FVA describes how a student uses his vision in a variety of natural environments
such as fluorescent lights, or dimly lit corridors.

Important for educators to design relevant instructional strategies

Most students with Vi have some usable vision

Learning Media Assessment (LMA) teachers determine appropriate reading
media fro students (Braille, audiotapes, computer screen readers etc….)

Disorders of the Eye

1. Myopia

2. Hyperopia

3. Astigmatism

Disorders of the Eye Muscles

For purposes of this class we will focus on:

1. Strabismus

2. Nystagmus
Disorders of the Cornea, Iris, and Lens

Corneal injuries and diseases are very serious because they may result in
permanent visual impairment. For purposes of this class we will focus on:

1. Glaucoma

2. Cataracts top

Disorders of the Retina

For purposes of this class we will focus on:

1. Diabetic Retinopathy

2. Retinopathy of Prematurely (ROP)

3. Retinitis Pigmentosa

Educational Considerations

o Classroom physical structure

o Provide alternative information for concept development

o Braille materials

> 10% of all school children have a visual impairment

> Approximately 50% of those have multiple handicaps

> 55% of those with multiple handicaps are male

> 45% of those with multiple handicaps are female

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