4.5: Blind and Vison Impairment

Blindness and Low Vision

Blindness and low vision have many different causes affecting different parts and functions of the eye. Vision relies on an interaction between the eye and the brain. Electrical signals travel from the retina through the optic nerve to the brain. The brain then turns the signals into images.

Typically, children with vision loss that can’t be fixed with glasses, contacts, or other methods have a visual impairment. Examples of vision impairment in children may be

• amblyopia (Lazy eye)
• strabismus (crossed eyes)
• eye or brain injuries
• birth defects.

Image Source: PxHere. CC0 Public Domain

Fig. 4.5. Toddler boy wearing glasses.

Definitions

IDEA

Individuals with Disabilities Education Act (IDEA) uses the term visual impairment and defines it as the following.

• Visual impairment including blindness means an impairment in vision that, even with correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness (IDEA, Part B)

Educators and clinicians should note that while the IDEA definition uses the term partial sight, the more commonly used term is low vision.

Wisconsin State Law

State laws often include definitions for blindness. Legal definitions are used for determining eligibility for government services (e.g., vocational rehabilitation for adults) rather than eligibility for special education and related services.

Blind and visually impaired means even after correction a child's visual functioning adversely affects educational performance. The IEP team may identify a child as blind and visually impaired after all of the following events occur:

• A licensed teacher of the blind and visually impaired conducts a functional vision evaluation which includes a review of medical information from an ophthalmologist or optometrist, formal and informal tests of visual functioning, and a determination of the implications of the blindness or visual impairment on the educational and curricular needs of the child.
• An licensed orientation and mobility specialist evaluates the child to determine if there are related orientation and mobility needs in home, school, or community environments. A child may meet the criteria under this subdivision even if they do not have orientation and mobility needs.

Visual Acuity

These laws are associated with visual acuity. Typically, a standard distance of 20 feet is used as a base measure of visual acuity. For example, an individual with 20/20 vision must be able to identify letters or objects at a distance of 20 feet. Visual acuity of 20/200 means that an individual can identify letters or objects at a distance of 20 feet that a typically sighted individual could see at 200 feet.

In addition, these definitions take into account the use of corrective lenses and the eye with the best vision using corrective lenses.

Image Source: American Foundation for the Blind

Fig. 4.5.1. Toddler girl learning braille.

Inclusion Strategies in the Classroom

• Take advantage of the student's residual vision.
  • if the child still has some useful vision, place him or her where he can easily see the most important parts of the room (you, classmates, storybook. whiteboard, video screen, etc.)
  • seat the student in a well-lit area - good lighting makes reading easier with low vision).
  • use handouts, books, and other reading materials that have good, sharp contrast
• Use non-visual information liberally.
  • explain visual things clearly - the layout of the classroom, the appearance of photographs in a textbook or of story lines in a video.
  • use hands-on materials wherever they will work - maps printed in three-dimensional relief or with different textures
  • allow the child to use Braille (an alphabet for the blind using patterns of small bumps on a page) if they know how.
• Include the student in the community of the classroom.
  • take care that the child is accepted into the social life of the class, as much as possible
  • recruit classmates to help explain visual material when necessary.
  • learn a bit of basic Braille and encourage classmates to explore it as well

Sources

• Blind and Visual Impaired. Special Education Disability Categories. Wiscosnin Department of Public Instruction.
• Physical Disabilities and Sensory Impairments. Educational Psychology (Seifert and Sutton). . Physical Disabilities and Sensory Impairments is shared under a CC BY 3.0 license and was authored, remixed, and/or curated by Kelvin Seifert & Rosemary Sutton (Global Text Project) via source content that was edited to the style and standards of the LibreTexts platform.
• Students Who Are Blind or Have Low Vision The Psychology of Exceptional Children. LibreTexts, Social Sciences Library.