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LEGAL BLINDNESS

Definition

In the United States the Social Security Administration defines legal blindness as

“central visual acuity of 20/200 or less in the better eye with the use of a correcting lens.” (Social Security Administration)

 

Let’s break that down. Visual acuity is defined as “a number that indicates the sharpness or clarity of vision” (Duffy 2013). Visual acuity is determined using chart called a Snellen Eye Chart (see image A). Acuity is written in a fraction like 20/200. The top number is the distance from the Snellen Eye chart in feet. The bottom number “indicates the distance at which a person with normal [people without disability] eyesight can read the same line.“ (McKinney 2016). That means that at 200 feet away from the Snellen chart a person with 20/20 vision could read the same as someone with 20/200 vision sees at 20 feet away. Therefore, if the higher the bottom number of the fraction is, the lower the visual acuity. These tests are given by trained by optometrist to ensure the legitimacy and accuracy of the results. It’s also important to notice that these tests are done while wearing corrective lenses.

Another definition of legal blindness is

“an eye that has a visual field limitation such that the widest diameter of the visual field subtends an angle no greater than 20 degrees…” (Social Security Administration).
In short, visual field limitation refers to peripheral vision and the spectrum of sight a person has (see image B).

       

The 2015 American Printing House for the Blind (APH) Annual Report states that there are

approximately 61,739 U.S. children in educational settings who are legally blind. (Children is defined as 0-21 years old.)
It’s important to note that it’s not uncommon for a person with legal blindness to have other eye conditions and fluctuations in their vision. For example, eye sight “may be influenced by factors such as inappropriate lighting, light glare, or fatigue…there is no ‘typical’ vison impaired student” (Marson 21). If a student is a person with other eye disabilities I recommend consulting useful website number 1 listed below for a glossary of eye conditions.

Image B
Visual field chart 
(Josephine C. Moore, PhD, 2001)

Image A
Snellen Eye Chart
(Jeff Dahl, 2007).

Instructional Strategies

Below is a fantastic compilation of strategies provided entirely by Training and Technical Assistant Center (TTAC online) in association with the Virginia Department of Education (VDOE)

  • Provide directions and instructions using the student’s preferred and strongest mode of communication. Many students will benefit from a multi-sensory approach that includes spoken language and tactile information.

  • Provide information to the student to indicate that a new task is beginning, the expectations for the lesson, and prepare the student for transitions to new activities. Consistency across routines will facilitate learning.

  • Allow opportunities for repetition and practice of previously introduced material.

  • Work with team members, student, and family to identify appropriate homework options and requirements.

  • Provide access to visuals presented at an appropriate distance and in the child’s visual field and allow plenty of time for descriptions and exploration of materials and activity.

  • Team members need to be aware of tactile sensitivity issues.

  • Consider environmental adaptations such as lighting conditions, contrast between materials, and the use of tactile cues in the room to promote independence and mobility.

  • Consider close proximity to the activity and teacher during instruction. Positioning of the student and the materials must be based on understanding the child’s acuity and any field loss concerns. For example, a child who has a field loss on the left side will need materials presented on the right side. Accurate information about the child’s vision and how that loss affects access to information are critical.

  • Carefully consider the arrangement of the classroom so that mobility is encouraged and comfortable for the child. Experiencing a simulation of a vision impairment may assist the child’s team in identifying features of the environment that need to be adjusted.

  • Consult with assistive technology specialists to discuss possibilities of low to high tech devices for increasing independence and participation. Some students with visual impairments will benefit from light boxes to increase contrast between objects and background and/or other devices to enlarge or magnify print and materials. Other options include Braillewriters, closed-circuit televisions, and screen enlargers.

  • Provide instruction at an appropriate pace, frequently checking for understanding and reteaching concepts as necessary.

  • Provide appropriate wait time for the student to respond to instruction or directions.

  • Have classmates and adults identify themselves as they answer or ask questions and participate in class discussion to allow the student to orient to the speaker.

  • Consider having the primary instructor positioned in one location during the lesson and away from glare.

  • Begin literacy activities by drawing on the concrete experiences of the learner. Start with vocabulary that is relevant to the student and provide supplemental experiences to help the child comprehend the meanings of new words.

  • While various reading approaches may be effective, students with visual impairments will need systematic instruction to effectively learn to recognize words, comprehend text, and use effective written language.

  • For beginning readers, pair real objects with representations (pictures, miniatures)

  • Encourage all reading efforts, including pretend reading and pretend writing. Consult with reading specialists to identify student’s stage of literacy and appropriate activities to move student to next level.

  • Use repeated readings to build fluency and comfort level.

  • Consult vision teacher and other team members about strategies for teaching Braille, when appropriate. Keep in mind the need for direct instruction, practice activities, consistency in instructors and expectations. See links below for additional Braille information.

  • Comprehension is strengthened by teaching the student specific strategies for increasing understanding. Students should be taught to ask who, what, where, and why questions to check their understanding of text material.

  • Written language should be taught systematically across all content areas and draw on the real-life experiences of the student.

  • Mechanics of writing, such as capitalization, punctuation and spelling, should be taught by teaching self-monitoring techniques (Silberman & Sowell, 1998).

  • Teach new vocabulary at a controlled pace and provide opportunities for interactions with peers (McNaughton, Hughes & Clark, 1994).

  • Consult AT specialists regarding the use of computer software that can be used to assist with writing assignments and reading of text.”

Useful Websites*
(*Click anywhere on the description of the website to open the website in another tab)
Research

This article from 2013 is great for math teachers. It details effective instruction practices geared toward teaching statistics. It talks about Nemeth code, which is braile for math. It mentions software which can translate homework assignments into Nemeth code. It mentions techniques such as the use of clay, modifying instruction, and visual tools, Pictures in Flash (PIAF), and requesting the help of art colleagues.

 

Marson, S. M., Harrington, C. F., & Walls, A. (2013). Teaching introductory statistics to blind students. Teaching Statistics, 35(1), 21-25. doi:10.1111/j.1467-9639.2012.00510.x


 

The Korea Institute of Science and Technology (KIST) explores methods of high quality instruction for the visually impaired in history class in this article. The experiment with 3 different types of 3D printers. Many textbook diagrams are meant to be described verbally they argue, “instructional materials should be prepared with easy, cheap, and customizable methods…students can use their sense of touch to recognize 3D tactile aids.” (Wonjin 115). For example, they printed a small 3D version of Buddhist grottoes to allow the student to feel and imagine the image more accurately. The innovative approach could certainly improve their learning process. It seems to be a great concept, but the costs of the process and safety of the final product still pose issues. It’s exciting to think that given that in the not so distant future 3D printing will become more affordable and readily available to make this a more realistic approach.


Wonjin, J., Jang Hee, I., Ananda Harianto, R., Ji Hyun, S., Hyebin, L., Heon Ju, L., & Myoung-Woon, M. (2016). Introduction of 3D Printing Technology in the Classroom for Visually Impaired Students. Journal Of Visual Impairment & Blindness, 110(2), 115-121.
 

 

This article form 2016 emphasizes that informed instructors can certainly make a difference! It highlights the importance of universal design for learning. In other words, providing students with “multiple means of expressing, learning, engaging with learning, and representing learning” (Ostrowski 19). This creates an inclusive classroom and makes students feel less isolated when using alternative methods such as assistive technology.

Ostrowski, C. P. (2016). Improving Access to Accommodations: Reducing Political and Institutional Barriers for Canadian Postsecondary Students with Visual Impairments. Journal Of Visual Impairment & Blindness, 110(1), 15-25.

legal blindness Perspective video

Video via James Rath Youtube

Consulted Resources

 “Children and Youth with Vision Loss.” American Foundation for the Blind, Jan. 2017, www.afb.org/info/blindness-statistics/children-and-youth/children-and-youth-with-vision-loss/235.

Duffy, Maureen A. “Low Vision and Legal Blindness Terms and Descriptions.” Low Vision and Legal Blindness Terms and Descriptions - VisionAware, 2013, www.visionaware.org/info/your-eye-condition/eye-health/low-vision/low-vision-terms-and-descriptions/1235.

“Instructional Strategies for Students with Visual Impairments.” TTAC Online, Virginia Department of Education (VDOE) , ttaconline.org/instructional-strategies-students-with-visual-impairments.

Marson, S. M., Harrington, C. F., & Walls, A. (2013). Teaching introductory statistics to blind students. Teaching Statistics, 35(1), 21-25. doi:10.1111/j.1467-9639.2012.00510.x

McKinney. “What Does 20/20 Vision Mean?” American Academy of Ophthalmology, 2017, www.aao.org/eye-health/tips-prevention/what-does-20-20-vision-mean.

 

McNaughton, D., Hughes, C.A., & Clark, K. (1994). Spelling instruction for students with learning disabilities: Implications for research and practice. Learning Disability Quarterly, 17, 169-185.

Sacks, S.Z. (1998). Educating students who have visual impairments with other disabilities: An overview. In S. Sacks, & R.K. Silberman (Eds.), Educating students who have visual impairments with other disabilities (pp. 3-38). Baltimore: Brookes Publishing Co.
 

Silberman, R.K., Bruce, S.M., & Nelson, C. (2004). Children with sensory impairments. In F.P. Orelove, D. Sobsey, & R.,K. Silberman (Eds.), Educating children with multiple disabilities: A collaborative approach (pp.425-525). Baltimore: Brookes Publishing Co.
 

Silberman, R.,K, & Sowell, V. (1998). Educating students who have visual impairments with learning disabilities. In S. Sacks, & R.K. Silberman (Eds.), Educating students who have visual impairments with other disabilities (pp.161-185). Baltimore: Brookes Publishing Co.

 

“Social Security Online.” Social Security Online - The Official Website of the U.S. Social Security Administration, Social Security Agency, 2018, https://www.ssa.gov/disability/professionals/bluebook/2.00-SpecialSensesandSpeech-Adult.htm
 

Ostrowski, C. P. (2016). Improving Access to Accommodations: Reducing Political and Institutional Barriers for Canadian Postsecondary Students with Visual Impairments. Journal Of Visual Impairment & Blindness, 110(1), 15-25.

Wonjin, J., Jang Hee, I., Ananda Harianto, R., Ji Hyun, S., Hyebin, L., Heon Ju, L., & Myoung-Woon, M. (2016). Introduction of 3D Printing Technology in the Classroom for Visually Impaired Students. Journal Of Visual Impairment & Blindness, 110(2), 115-121.

Images:

Dahl , Jeff. “Snellen Chart.” Wikipedia, Wikimedia Foundation, 23 July 2008, en.wikipedia.org/wiki/Snellen_chart#/media/File:Snellen_chart.svg.

Moore, Josephine C. “Pedretti and Early, 2001.” The Free Dictionary, Farlex, 2001, medical-dictionary.thefreedictionary.com/acuity.

Rath, James, creator. What I Can and Can't See as a Legally Blind Person. YouTube, 27 Sept. 2017, www.youtube.com/watch?v=7cLyjzTFjdA.

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