Sensory Impairments
Sensory Impairments refer to the reduced ability or lack of ability in using one or more of three senses: vision, touch, and hearing. Also included blindness and deafness. Hearing Loss has already been covered with the communication disorders so in this section the primary focus will be about vision and then the strategies teachers can use to help students with a communication disorder or sensory impairment.
Vision Loss Definitions
Classification of Vision Loss
Muscle Disorders – inability to maintain tension
Prevelance
Causes
Characteristics of Vision Loss Intelligence
- Legal Blindness- vision cannot be corrected better than 20/200
- Partial Sight or low vision- vision is better than 20/200 but worse than 20/70 after correction.
- Braille- system for writing for the blind that involves combinations of six raised dots punched into paper, which is read using fingertips
Classification of Vision Loss
- Refraction Problems – cornea or lens fail to focus light rays properly on the retina
- Hyperopia – eyeball is short, flat cornea – cannot see items from close range
- Myopia – eyeball is long, increase curve of cornea – cannot see from a distance
- Astigmatism – uneven curvature of the cornea, light rays converge at many points – produces unclear or distorted images
- Cataracts – lens become opaque – blindness or distorted vision
Muscle Disorders – inability to maintain tension
- Nystagmus– uncontrolled rapid eye movement
- Strabismus – crossed eyed
- Amblyopia – an eye that appears normal but doesn’t function
- Receptive Eye Problems – Damage to retina or optic nerve
- Optic Atrophy – nerve fibers that connect the retina to the brain is degenerative
- Retinitis pigmentosa – night blindness – degeneration of the retina
- Retinal detachment – results from glaucoma, or trauma to the eye
- ROP – too much oxygen to infants causes loss to blindness
Prevelance
- 20% of Americans have some vision loss but can be corrected
- 1 in 3,000 children are legally blind
- 3% of the total population (9million) have significant vision loss that requires specialized services
- 26,000 school age children are being served in special education because of vision loss
Causes
- Genetic Disorders
- Glaucoma
- Albinism
- Degeneration of the Retina
- Cataracts
- Acquired Disorders
- Infections
- Radiation
- Drugs
- Vitamin A Deficiency
- Trauma
- Tumors
- Trachoma
Characteristics of Vision Loss Intelligence
- Speech and Language Skills
- Academic Achievement
- Social Development
- Orientation and Mobility
- Perceptual Motor Development
Tips for General Education Teachers:
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Accommodations
- Copies of overhead projector/smart board activities to be viewed at his/her desk as needed.
- The teacher or presenter should verbalize all information as it is written on the board or overhead.
- Information presented on the board should be in a high contrast color.
- Use a slant-board to position papers appropriately for reduced visual strain and to avoid glare.
- The computer screen should be eye level and tilted to avoid glare.
- Use recorded text as needed.
- Classroom recording of lectures/instruction by student.
- Large Print textbooks/materials.
- Braille textbooks/materials.
- Clear, dark copies of worksheets.
- Use of a reading guide to assist in keeping place while reading and completing worksheets.
- Present materials against a plain background
- Use a good contrast background and present on a contrasting tray or mat.
Environmental resources:
- Avoid glare in general from overhead lights. Consider placing light filters on fluorescent lights.
- Open and close doors fully (a half open door can be a dangerous obstacle).
- Eliminate unnecessary background noise. Consider isolation headphones.
- Eliminate clutter from the room, particularly in aisles and movement paths.
- Place materials in consistent places so that students know where particular items are always located.
- Preferential locker position and locks with keys vs. combination locks.
- Use of task lighting as needed.