Visual Impairment
Eileen Sisk, Gina Sparrow, Kirstin Warden, Annie Nguyen
Part I. Background Information
Source: National Dissemination Center for Children with Disabilities (http://nichcy.org/disability/sp ecific/visualimpairment)
- DEFINITION
- Visual impairment in educational context refers to students who are:
- “partially sighted” - having some sort of visual problem, leading the child to require special education
- “low vision” - severe visual impairment, not limited to distance vision (could be close up and still can’t see!)
- “legally blind” - having less than 20/200 vision in the better eye OR having a reduced vision field (less than 20 degrees)
- “totally blind” - require braille or other non-visual media/stimuli.
- CAUSES
- Visual impairment ≠ eye disorder, but the CONSEQUENCE of an eye disorder.
- Eye disorders causing visual impairment may include: retinal degeneration, albinism, cataracts, glaucoma, strabismus, muscular problems, corneal disorders, diabetic retinopathy, congenital disorders, infection.
- Other causes:
- Leading cause of visual impairment around the world: refractive error
- Vitamin A deficiency
- Brain/ocular trauma
- CHARACTERISTICS
- Visual impairment affects each child’s development differently, depending on the severity, type of vision loss, age of onset, and child’s overall functioning level.
- kids with multiple disabilities who also have visual impairments can have delays in cognitive, motor, and social skills. With vision loss, these skills can be further delayed.
- kids who can’t see well have little reason to explore their environment & miss many learning opportunities available through sight.
- not being able to see parents and peers limit these children’s social development. They can’t imitate social behavior or comprehend nonverbal cues.
- PREVALENCE
- National Dissemination Center for Children with Disabilities (2004) http://nichcy.org/disability/specific/visualimpairment
- Visual impairments in general - under 18 years of age in US: 12.2 per 1,000
- Legally blind or totally blind - under 18 years of age in US: .06 per 1,000
- British Journal of Ophthalmology, Pascolini & Mariotti (2011) http://bjo.bmj.com/content/early/2011/11/30/bjophthalmol-2011-300539.abstract
- In 2010, around the world:
- 285 million people are visually impaired; 39 million of them are blind
- people 50+ yo represent 65% of the visually impaired and 82% of the blind
Part 2. Component View of Literacy (For Visual Impairment)
- PHONOLOGICAL PROCESSING IN BRAILLE
- Dyslexia 5, University of Manchester, Greaney & Reason (1999)
i. Study acknowledges contributing factors in learning to read Braille: tactile sensitivity, perception,and memory. What about phonological processing?
ii. Earlier exposure to letters for children with sight (i.e., billboard advertisements and on food items in grocery) than to Braille for children who are blind.
iii. For study, a modified version of Phonological Assessment Battery (PhAB) was developed and used to capture phon. processing skills of Braille readers. Subtests included: alliteration, rhyme, segmenting spoonerisms, fluency, and non-word reading (decoding letter strings). Results compared with norms for same age/level peers using standardized Neale Analysis of Reading Ability (NARA).
iv. Participants = 22 Braille readers (who spoke English fluently) between ages 7:10 and 12:1 years from four schools for visually impaired students.
v. Results = As a group, the Braille readers did not read as well as their same-age sighted peers, but performed higher/better on phonological processing pieces of subtests.
- THE ABC BRAILLE STUDY
- Journal of Visual Impairment and Blindness; Emerson, Holbrook & D’Andrea (2009)
i. Braille contains 189 contractions (in addition to letters) in its alphabet. This acknowledged, the above study set out to determine whether early vs. late introduction of these contractions was better conducive to acquiring literacy skills.
ii. Differences in reading rate, vocabulary, comprehension, word recognition, and level of reading achievement were examined. [Was the first longitudinal study of children as Braille learners!]
iii. Participants = From 15 different states, each child started in prekindergarten or kindergarten and ended near 3rd or 4th grade. Reading scores/results were obtained from 18 students years 1 and 2 and 6 students year 3 (loss of consent/moving/identification of other illnesses were factors ruling out data).
iv. Results = Spelling was a strength for both groups of Braille readers; however, students introduced to contractions early tended to perform higher on spelling and vocabulary measures.There was no correlation between reading speed and whether contractions were taught early on. Finally, acquiring higher level decoding skills from 2nd grade forward (in reading connected texts) was difficult for all Braille readers.
- Literacy in Early Intervention for Children with Visual Impairment
- Erikson, K. A., Hatton, D., Roy, V. Fox, D., & Renne, D. (2007). Literacy in early intervention for children with visual impairment:Insights from individual cases. Journal of Visual Impairment & Blindness.
- This study provides, “practical insights into the role of the early interventionist in supporting early literacy development.”
- Reviews the effect of limited visual feedback (and restricted ability to explore the world around them) on general language development, resulting in overall delayed language
- This study was a case study design, and discusses the role of family-centered therapy and the early interventionist in laying the ground work for future literacy.
- Chronic Cortical Visual Impairment
Huo, R., Burden, S.K., Hoyt, C.S., & Good, W.V. (1999). Chronic cortical visual impairment in children: aetiology, prognosis, and associated neurological deficits. British Journal of Opthamology.
- According to a local SLP in Bloomington, CVI (Cortical Visual Impairment) is an increasingly common diagnosis in the schools, despite this article’s report that over the past 15 years only 2.4% of visually impaired children seen at a pediatric opthamology practice in london received the diagnosis. I included this in our disability project because this SLP recommended that any new SLP in the schools become more familiar with this disorder.
- According to this article, CVI was diagnosed based on the following qualifications:“(1) vision loss in the absence of signs of anterior visual pathway disease, or (2) vision loss greatly exceeding that which would be expected, given the findings of an ocular examination.”
- The four most common causes of CVI were perinatal hypoxia (22%), cerebral vascular accident (14%), meningitis (12%), and acquired hypoxia (10%).
- Most children with CVI had associated neurological abnormalities. The most common were seizures (53%), cerebral palsy (26%) hemiparesis (12%), and hypotonia (5%). Associated ophthalmological problems were esotropia (19%), exotropia (18%), optic nerve atrophy (16%), ocular motor apraxia (15%), nystagmus (11%), and retinal disease (3%).
- According to this article, the vision of children with CVI could be slightly improved, but it was not stated how this was accomplished, and it did not correct these children’s vision entirely.
- Reading Rate and Comprehension
- Corn, A.L., Wall, R.S., Jose, R.T., Bell, J.K., Wilcox, K., & Perez, A. (2002). An initial study of reading and comprehension rates for students who received optical devices. Journal of Visual Impairment and Blindness, 96(5).
- Children with visual impairment across grade levels are at risk for the development of low literacy skills
- Findings: Children who received optical devices improved silent reading rate and comprehension scores
- Slow reading rates can lengthen the time it takes for a child to complete an assignment, impacting academic achievement
- Need for instruction in near-vision and distance devices in order to enhance literacy skills
- Silent reading speed for the vision impaired group of students was reduced compared to peers - silent reading rate improved with a device, but oral reading rate did not
- Improvement was made in both oral and silent reading comprehension
- The introduction of optical devices is important for the development of literacy skills - children have better access to the text that surrounds their environment on a daily basis
- See also Visual Requirements for Reading
- Low Vision and Spelling
- Gompel, M., van Bon, W.H.J., Schreuder, R., & Adriaansen, J.J.M. (2002). Reading and spelling competence of Dutch children with low vision. Journal of Visual Impairment and Blindness, 96(6).
- Just as in reading rate and comprehension, children with visual impairment were expected to be behind their peers in spelling ability due to lack of text input and sound mapping
- No major discrepancy was found in spelling for students with low vision in regular schools - there was a trend of poorer performance for students with low vision in special schools, however
- Nonvisual factors such as cognitive ability, native language, presence of learning disabilities or attention deficit disorders should be considered
- Conclusions: children with visual impairment form a heterogeneous group and may not show spelling deficits, therefore an individual educational approach specific to each child’s needs should be considered
- See also Spelling for the Visually Impaired Child
- Websites:
- Family Connections for raising a child with visual impairment
- This website has links for each stage of child development, including school age, and teenage.
- The website has links to switch into Spanish and into English
- Of particular interest for our class is a list of “expanded core curriculum” which are the extra set of skills that a visually impaired student will need to learn to successfully navigate their home and educational environment.
- http://nichcy.org/disability/specific/visualimpairment
- This website belongs to the National Dissemination Center for Children with Disabilities. It is a comprehensive resource with a lot of information on visual impairment. Here, you can find links for educators (i.e. info on how to work with children with visual impairment, instruction accommodations, etc.) as well as links to various organizations for the blind (e.g. American Foundation for the Blind, Blind Children’s Center, and many more!).
- Multimedia
15 minute video produced by the National Federation for the Blind (the organization Helen Keller worked with). Discusses the benefits of learning braille, reasons for low rates of braille literacy in the low vision and blind population (only 10% of these students are taught Braille), and braille myths are busted.
iPhone 4S linked to a Braille display
How Braille can be used to make iPhones accessible to visually impaired Braille readers. An example of how Braille can provide access to
iPad accessibility for the visually impaired: voice over
Another video about ways for apple products to be accessed
very interesting to think about - a lot of students with Cortical Visual Impairment (a term that always drove me crazy) - have other disabilities as well - so you might be thinking about not only literacy skills but also access to assitive technology devices, symbols, etc. used to communicate.
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