Visual Impairment

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Visual Impairment

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Visual Impairment

Jordan Danner & Amanda Downum

“The word blind has always meant more than merely the inability to see…. Throughout history of the language and in common usage today, the word blind connotes a lack of understanding… a willful disregard, a thing meant to conceal or deceive. In fact, when you stop to listen, the word is far more commonly used in its figurative than its literal sense. And it comes up so often: blind faith, blind devotion, blind luck, … blind alley…. blind taste test, double-blind study, flying blind,…. Blind submission, blind side, blind spot….Pick up any book or magazine and you will find dozens of similes and metaphors connecting blindness and blind people with ignorance, confusion, indifference,



(Exceptional Learners, 2012, p. 331)



Quiz Time



Myth: People who are legally blind have no sight at all. Fact: Only a small percentage of people who are legally blind have absolutely no vision. Many have a useful amount of functional vision.

Myth: Stereotypic behaviors (body rocking, head swaying) are always maladaptive and should be totally eliminated. Fact: If not done to the extreme, they can actually help persons who are blind regulate their levels of arousal.

Myth: People who are blind automatically develop better acuity (sharpness) in their other senses. Fact: This is not automatic but rather represents learning to use received sensations better.

Myth: People who are blind have an extra sense that enables them to detect obstacles. Fact: No extra sense. Some learn to develop an “obstacle sense” by noting the change in pitch of echoes as they move toward objects.

Source: (Exceptional Learners, 2012, p. 12-13)



5. Myth: Braille is not very useful for the majority of people who are blind; it should only be used as a last resort.

Fact: Very few people who are blind have learned Braille, mostly due to fear that using it is a sign of failure and historical bias against it. Authorities do acknowledge that utility of Braille for people who are blind.

6. Myth: If people with low vision use their eyes too much, their sight will deteriorate.

Fact: Only rarely is this true. Visual efficiency can actually be improved through training and use. Wearing strong lenses, holding books to the eyes, and using the eyes often cannot harm vision.

7. Myth: Technology will soon replace the need for Braille and for mobility aids such as the long cane and guide dogs. In addition, a breakthrough for restoring complete sight through technology is just around the corner.

Fact: As amazing as some of the technology is in the field of vision impairment, it’s doubtful that it will be as effective as Braille, the long cane, or guide dogs anytime soon. Research on artificial vision is exciting, but it too does not promise huge practical benefits for some time.

Source (Exceptional Learners, 2012, p. 330-331



Activity – an “idea” of what it’s like to be an individual with a Visual Impairment



Legal Definition

Legally Blind

: has visual acuity of 20/200 or less in the better eye even with correction (e.g. eye glasses) or has a field of vision so narrow that its widest diameter subtends an angular distance no greater than 20 degrees.

20/200 means that the person sees at 20 feet what a person with normal vision sees at 200 feet.

Normal visual acuity is 20/20

The inclusion of a narrowed field of vision in the legal definition means that a person may have 20/20 vision in the central field but severely restricted peripheral vision. Legal blindness qualifies a person for certain legal benefits, such as tax advantages and money for special materials.

Low Vision (partially sighted)

Persons who have low vision have visual acuity falling between 20/70 and 20/200 in the better eye with correction.

Source (Exceptional Learners, 2012, p. 332)



Many educators find the legal definition insufficient.

They have observed that visual acuity is not an accurate predictor of how people will function or use whatever remaining sight they still have.

Only a small percentage of individuals who are legally blind have absolutely no vision,

the majority can see to some degree

The “Educational Definition”

Includes reading:

Blindness is “needing” to use Braille or auditory methods

Low vision is being able to read print (enlarged or magnified

Source (Exceptional Learners, 2012, p. 333)



Michigan Administrative Rules Definition:

R 340.1708 Visual impairment explained; determination.

(1) A visual impairment shall be determined through the manifestation of both of the following:

(a) a visual impairment which, even with correction, interferes with development or which adversely affects educational performance. Visual impairment includes both partial sight and blindness.

(b) one or more of the following:



) A central visual acuity for near or far point vision of 20/70 or less in the better eye after routine refractive correction.

(ii) A peripheral field of vision restricted to not more than 20 degrees

(iii) A diagnosed progressively deteriorating eye condition.



Michigan Administrative Rules definition continued:

(2) A determination of impairment shall be based upon a comprehensive evaluation by a multidisciplinary evaluation team, which shall include an ophthalmologist or optometrist.

(3) If a student cannot be tested accurately for acuity, then functional visual assessments conducted by a teacher certified in visual impairment may be used in addition to the medical evaluation for determination of impairment.

(4) For students with visual impairment who have a visual acuity of 20/200 or less after routine refractive correction, or who have a peripheral field of vision restricted to not more than 20 degrees, an evaluation by an orientation and mobility specialist shall be conducted. The orientation and mobility specialist shall also include in the report a set of recommended procedures to be used by a mobility specialist or a teacher of students with visual impairment in conducting orientation and mobility training activities.

Source (Special, 2009, part 1 page 13 and 14)



Blindness is primarily an adult disability

Federal government classifies only about .05% of the population ranging from 6 to 17 years of age as “visually impaired”

Include both those who are blind or who have low vision

Probably underestimated because of co-morbid disabilities

School are instructed to report only the “primary” condition

Visual impairment in one of the least prevalent disabilities in children


Identification of Visual Impairment

Visual acuity is defined as the ability to see fine details

Visual acuity is most often measured with the



Consists of rows of letters (for individuals who know the alphabet)

For very young children and/or those who cannot read, the chart has rows of the letter E arranged in various positions. The person’s task is to indicate in what direction the “legs” of the E’s face.

Rows of letters or E’s - each corresponds to the distance at which the individual can see: (15, 20, 30, 40, 50, 70, 100, and 200 feet)

Normally start at 20 and move up if needed

Examples: 20/20, 20/70, 20/200


Snellen Chart




Identification continued





have limitations

First, it’s a measure of visual acuity for distant objects, and a person’s distance and near vision sometimes differ.

Assessing near vision usually involves naming letters that range in size from smaller to larger on a card that is at typical reading distance from the person’s eyes.

Second, visual acuity doesn’t always correspond with how a student actually uses his vision in natural settings,

Variable environmental conditions

Functional Vision Assessment

Involves observing the student interacting in different environments.


Anatomy and physiology of the eye

Page 334 in “Exceptional Learners”

The object “being seen” becomes an electrical impulse that is sent through the optic nerve to the “visual center”

Before reaching the optic nerve, light rays reflect off the object and pass through several structures in the eye


Aqueous humor




Vitreous humor


Optic Nerve


Signs of Possible Eye Trouble in Children

Teachers can sometimes play a key role in identifying students with VI, so they should always be alert to the following signs:

Appearance of eyes

Eyes don’t line up, one eye appears crossed or looks out

Eyelids are re-rimmed, crusted, or swollen

Eyes are watery or red (inflamed)

Actions of child

Rubs eyes a lot

Closes or covers one eye

Tilts head or thrusts head forward

Has trouble reading or doing other close-up work, or holds objects close to eyes to see

Blinks more than usual or seems cranky when doing close-up work

Things are blurry or hard to see

Squints eyes or frowns

Child might say

“my eyes are itchy,” “my eyes are burning,” or my “my eyes feel scratchy.”

“I can’t see very well.”

After doing close-up work, your child says “I feel dizzy,” “I have a headache” or “I feel sick/nauseous.”

“Everything looks blurry,” or “I see double.”

*One or more of these signs appear, the child should see an eye doctor right away

Source: (Exceptional Learners, 2012, p. 35)


Causes Affecting Children and Adults

In both children and adults, the most common visual problems are the result of errors in refraction

Refraction refers to the bending of the light rays as they pass through the various structures of the eye

Myopia (nearsightedness),


(farsightedness), and astigmatism (blurred vision) are examples of refraction errors that affect central visual acuity.

Usually can be corrected by wearing glasses or contact lenses


Causes Affecting Children and Adults

Page 337 in “Exceptional Learners”

Glaucoma: is actually a group of eye diseases that causes damage to the optic nerve.

Referred to as the “sneak thief of sight” because it often occurs with no symptoms

Detected through an eye exam

More frequently in older people, professionals recommend increasingly frequent checkups, starting at age 35

Cataracts: are caused by a clouding of the lens of the eye, which results in blurred vision.

In children, the condition is called congenital cataracts

Both distance and color vision are seriously affected

Surgery can usually correct problems caused by cataracts


Causes Affecting Children and Adults

Diabetic retinopathy: a condition that results from interference with the blood supply to the retina

Caused by Diabetes


Causes Primarily Affecting Children

Cortical Visual Impairment (CVI): Leading cause of visual impairment in children. Results from widespread damage to parts of the brain responsible for vision

Can be a result of various causes, which include: head injury or infection.

With CVI a unique pattern of visual responses seem to occur

Avoidance of looking at new visual information

A preference for looking at near objects

Nonpurposeful gazing

Distinct color preferences

Attraction to rapid movements

Abnormal visual reflexes


Causes Primarily Affecting Children

Retinopathy of prematurity (ROP): results in abnormal growth of blood vessels in the eye, which then causes the retina to detach. Associated with high levels of oxygen administered to premature infantsBeing born very prematurely


Causes Primarily Affecting Children

Optic nerve hypoplasia (ONH): involves underdevelopment of the optic nerve. The underdevelopment is often associated with brain abnormalities.Often at risk for problems with speech and cognitive disabilitiesCause or causes of ONH are still unknown


Other Causes



: hereditary condition that results in degeneration of the retina.

Can start in infancy, early childhood, or the teenage years.

Usually causes the field of vision to narrow (tunnel vision) and also affects one’s ability to see in low light (night blindness)

Strabismus (crossed eyes): a condition in which one or both eyes are directed inward or outward. If left untreated, it can result in permanent blindness. Can usually be treated through eye exercises or surgery.


: a condition in which rapid involuntary movements of the eyes occur, usually resulting in dizziness and nausea. It can be a sign of brain malfunctioning and/or inner-ear problems.


Psychological and Behavioral characteristics

Language Development

Lack of vision does not have a very significant effect on the ability to understand and use language.

Maybe a slight delay in infancy

Might be even more motivated to use language because it’s the main channel through which they can communicate with others.

Intellectual Ability

No reason to believe blindness or other visual impairments results in lower intelligence.

Might have slight delays in conceptual (intangible) development – usually does not last long

Motor delays are also common in infancy. It is important to encourage infants to explore their environment and overcome these delays.


Psychological and behavioral Characteristics

Orientation and Mobility (O & M)

These refer to the ability to have a sense of where one is in relation to other people, objects, and landmarks (orientation) and to move through the environment (mobility).

Very important for the successful adjustment of people with visual impairment.

People with visual impairment can process spatial information either sequentially or as a cognitive map – which is more efficient.

Mobility skills vary greatly among people with visual impairment.

Obstacle sense: some people with visual impairment use this sense, which is the ability to detect objects by noting subtle changes in high-frequency echoes (the Doppler effect)


Psychological and behavioral Characteristics

Academic Achievement

Some students who are blind experience low academic achievement, probably due to low expectations or lack of exposure to Braille.

Phonological awareness is very important for learning to read both print and Braille.

Social Adjustment

Most people with visual impairment are socially well adjusted.

Any problem with social adjustment usually comes about due to sighted society’s reaction.


Skit “appropriate conversational behaviors”


Dos and Don’ts for teachers working with students with visual impairments

DoDon’tFeel comfortable using vision words, such as “look”, “see”, and “watch.”Be afraid to touch visually impaired students, but tell them you are about to touch them; respect student’s personal preferences about touching.Use the student’s name when calling on them.Overprotect; let students try as many things as possible for themselves.Read out loud what you are writing on the board.Worry about your initial feelings of awkwardness; remember that you are teaching a child – who happens to have a disability. Encourage independence; visually impaired students need to learn to do as much as possible for themselves. Be afraid to require a student’s best work.Include visually impaired students in as many class activities as possible. Be afraid to require good behavior; administer the same discipline, if needed, as you would for a child who is sighted; rules do count. Give explicit directions; avoid the words here and there because they may not give enough information.Hesitate to ask students what something looks like to them; it may help you understand the quality of the student’s vision.Fill in experiential gaps when you discover them.Feel you must tolerate unacceptable behavior in students who are visually impaired anymore than you would in students who are normally sighted. Allow extra time when needed, for tactual exploration, when appropriate, slower visual/Braille reading, etc. Provide extra storage space for special equipment/materials.Encourage the use of aids/devices (not aides).

Source: Exceptional Learners, p. 345


Educational considerations

In many ways, students who are visually impaired should be educated in the same general way as sighted children.

However, teachers need to make important modifications


Use of remaining sight

Listening Skills

O & M training (Orientation and Mobility)

(Braille, use of remaining sight, and listening skills pertain directly to academic education – reading. O & M training is used for skills needed for everyday living)





century, Louis Braille introduced a system of reading and writing for people who were blind.

The basic unit of Braille is a quadrangular cell, containing from one to six dots. Different patterns of dots represent letters, numbers, and punctuation marks.

Alphabet letter and contractions

Best method is to use both hands

The ability to use Braille is a crucial skill

It is not being used as much, very low level

Federal law requires that if any member of the IEP team, including parents, thinks Braille is a necessity it must be made available for the student.

People with low vision can also benefit from the use of Braille


Braille Activity


Educational Considerations

Use of remaining sight

Important Skill

Large-print books

Magnifying devices can be used for close of distance vision

Listening Skills

**Extremely Important**

Must be taught to listen


Educational Considerations

O & M Skills

Long cane

Some individuals refuse to use the long cane

Guide Dogs

More practical for adults as opposed to children

Tactile Maps

Human guides

Not always recommended, but can be useful at times

Technological aids

Becoming increasingly important

Include: Braille note takers, personal data assistant, Newline Descriptive Video Service, and screen readers for computers

O & M aids

Obstacle-detection devices

Global positioning system (GPS)

Learners with visual impairment should not become so dependent on technology that they neglect basic techniques


Affects on VI Children and their Families

Children may feel like they’re the only student getting accommodationsMay lack role modelsLack of sense of independenceAlmost all visually impaired children wish they were sighted

Families may need time to adjust

May try to find visually impaired individuals to play with children and act as model

May join groups such as NAPVI


Service delivery models

Four major educational placements

Residential School

Special class

Resource room

General Education class with itinerant teacher help


Transition into Adulthood and Employment

“Good” Preparation and support from families is crucialMust receive proper transition programmingIntensive and extensive Do not start later than middle school


Many adults with VI are unemployed

Overqualified for the jobs they hold

Individuals with VI can hold a job at any level with proper transition programming

Job accommodations are essential


“Skill Quiz” p. 333

One of the challenges for teachers and parents is to identify skills and alternate techniques that persons who are blind can use to perform everyday tasks

How might a blind person…

1. Keep track of where his/her toddler is?

2. Shop at a supermarket

3. Grill meat on a barbeque?

4. Go on the Internet?

5. Pour a glass of juice?



Administrative Rules for Special Education 2009. Obtained online at Michigan Department of Education.

Cronin, M.E., Patton, J.R., & Wood, S.J. (2007).

Life skills instruction: A practical guide for integrating real-life content into the curriculum (2



Austin, TX: Pro-ed.


, D., Kauffman, J., & Pullen, P. (2012).

Exceptional learners: An introduction to special education (12




, D.B., Papadopoulos, K.S.,


, A.C.,


, V.E., &


, M.S. (2009). Factors affecting the reading media used by visually impaired adults.

The British Journal of Visual Impairment

, 27 (2), 111-127.


: 10.1177/0264619609102214


, B., Frost-Olsen, S.,


, T., & Marshall, E. (2003). The relationship between family and sibling functioning in families


a child with a disability.

Journal of Family Nursing

, 9, 365-396.


: 10.1117/1074840703258329






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