Learning About Disabilities: Information on Visual Disabilities
3 Categories of Visual Disability
- Individuals who are visually impaired have an acuity between 20/80 and 20/200 with correction in the better eye.
- Individuals who are legally blind have an acuity of 20/200 or less, with correction in the better eye.
- Individuals who are blind have no measurable acuity, though they may have some sensitivity to light.
Visual Acuity is a standardized scale. For instance, an acuity of 20/100 indicates that the person only sees at 20 feet what a fully sighted individual sees at 100 feet.
Making Printed Materials Available
No matter what the degree of visual disability, there will be a need to modify standard print materials so that they are accessible to the person with the visual disability. There are multiple methods for making print materials accessible.
Braille is used by many blind individuals. Printed materials can be transcribed into Braille. Notes can be written in Braille. There are many adaptive technical products that read, write, and print in Braille. The Sight Enhancement Center, located in ESS, has a Braille printer for student use.
Audio-taped or E-text materials are frequently used by persons with visual disabilities. National organizations and campus readers can audio-tape printed materials. Books maybe scanned into E-text and read by a screen reader. Typically, reading lists need to be obtained in advance to provide adequate lead time for obtaining taped text or E-text materials.
Close-Circuit Televisions (CCTV) enlarge print material that is placed on a movable tray, and the magnified image of the document is projected onto a screen. CCTV's are available in most of the Case libraries and in the Sight Enhancement Center.
Scanner and Voice output equipment reads aloud printed materials through a MAC or PC. The Sight Enhancement Center has Open Book and Bookwise programs for reading print material, as well as a Kurzweil Reading Edge.
Software-driven text enlargement programs display text on the video display terminal with a variable degree of magnification. This is available in the Sight Enhancement Center and is easy to load onto a PC or Mac. Personal magnifiers can often be used to read printed materials. High powered magnifiers can often help individuals read handout materials that can be held close to the eyes.
Large print text materials are available in many libraries. Enlarging a letter-size document to a legal-size document is one method of enlarging print. Commercial large print materials are usually in an 18 or 20 point font; however, enlarging print to any size that makes it readable for the individual is appropriate.
Classroom Considerations
- Reserve seating in the front of the room for students with visual impairments. The student may need to be close in order to get a quality tape-recording of the lecture, or the student may be able to read some materials presented on the board or an overhead.
- Provide handout materials of any board work or overhead materials. Students can have someone read this to them later or may be able to magnify it outside of class.
- Avoid talking into the board when writing. Tape-recorded lectures are not helpful if the voice is muffled.
- Spell new vocabulary as you write it on the board or on an overhead.
- Allow extra time for reading assignments. Students will need additional time either to obtain the materials on audio tapes, transfer them into Braille, enlarge them, or read them with magnification equipment. Giving reading assignments ahead of time is very helpful.
- Develop an individualized method for students with visual disabilities to do in-class assignments. Have them work with a partner, read aloud to them and have them dictate to you, or give assignments ahead of time so that they can prepare them before class.
- Work with the student to identify the appropriate means for test-taking. Coordinate your efforts with ESS for special arrangements.