Chapter TwelveIndividuals With Individuals With

Visual ImpairmentsVisual Impairments

Defining Visual Impairments

IDEA definition: Visual impairment that, even with correction, adversely affects an individual’s educational performance

Legally blindCorrected vision has acuity of 20/200

or lessFunctionally blind

Very limited visionLow vision

Minimal visionWatch this video of an eye examination.

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The Eye and How it Works

Light enters the eye through the cornea and then moves through the iris into the pupil. The light is converged by the lens and moves through the vitreous humor to focus on the retina where the light is changed into electrical signals that are sent along the optic nerve to the occipital lobe of the brain for interpretation as visual images.

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The Eye and How it Works

Myopia (near sightedness)Light focuses before it reaches the

back of the eyeHyperopia (far sightedness)

Light has not focused when it reaches the back of the eye

Astigmatism One or more surfaces of the cornea or

lens are not spherical but cylindrical

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Brief History of the Field1700s

First school for blind youth (in Paris)1800s

Louis Braille created a system of Braille dots for communication

Schools for the blind opened in the U.S.1950s and 1960s

Public school classes for child with visual impairments

1970sVision training to maximize residual sightIDEA requires specialized services and

access to public school classrooms

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Prevalence of Visual Impairments 2.8% of American school-aged children

experience a vision loss significant enough to require special education

The U.S. Department of Education reports approximately 26,000 children ages 6-21 received special education services during the 2008-2009 school year

Low-incidence disability

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The Vision Process and Etiology of Visual ImpairmentsCornea

Damage/infection limits acuity and visual field

Aqueous fluidGlaucoma limits acuity and visual field

IrisMalformation causes light sensitivity

LensCataracts affect vision, color, light

sensitivity

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The Vision Process and Etiology of Visual Impairments

Vitreous bodyInfection/disease blurs and distorts vision

RetinaLight disruption results in blurred vision

Rod cells in retinaShape, motion, photosensitivity

Cone cells in retinaColor

Watch this video to learn more about the macular degeneration process

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Prevention of Visual Impairments

Most visual impairments are genetic Prenatal care Early detection through vision screening Eye safety

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Characteristics of Individualswith Visual Impairments Academic performance Social and emotional development Educational implications Independent living skills Vocational skills

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Assessment of Individualswith Visual Impairments

Snellen chart Functional visual evaluation

o Literacy mediumo Learning mediao Large printo Grade 1 Brailleo Grade 2 Braille

Learn more about reading Braille in this video

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Young Children with Visual ImpairmentsEarly intervention

Individualized family service plan (IFSP)Early childhood programsPrograms for young children with visual

impairments teach:Visual and auditory skills, sensory

development, fine and gross motor development, social development, receptive and expressive language development, self-help development, daily living skills

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Transition into AdulthoodTransition planning includes:

Vocational trainingPostsecondary educational

opportunitiesTravel skills (orientation and mobility)Use of community resourcesSocial adjustmentIndependence

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Adults with Visual Impairments

• Employment possibilities and acquiring job skills

• Leisure time activities and community participation

• Orientation and mobility training• Using technology

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Family Issues

Services Advocacy Education

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Issues of Diversity

Cultural susceptibility to eye diseases Socioeconomic status influences

availability of eye care Cultural implications

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Technology and Individuals with Visual Impairments Assistive technology Technology and literacy PL 108-446 requires the IEP team to

consider the provision of assistive technology devices and services in the development of the student’s IEP. Under IDEA, Braille instruction is required unless the IEP team determines that it is not appropriate after evaluation of the student’s reading and writing skills, needs, and appropriate reading and writing media.

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Trends, Issues, and Controversies

Teacher shortages Orientation and mobility specialist

shortages Reading media assessment

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