Individuals who are Blind or have Low Vision

Blindness or low vision is likely to occur in the student population. Approximately 45% of individuals with severe low vision or blindness have a high school diploma. Among high school graduates, those with severe low vision or blindness are about as likely to have taken some college courses as those who were sighted. At least 2.5 million Americans who are blind or have low vision use computers.

Common vision problems, which may fluctuate in severity and/or deteriorate over time, include:

Poor acuity,
Near or far-sightedness,
Extreme sensitivity to light and/or glare,
Color distortions,
Visual field defects,
Spots before the eyes, and
Central vision loss.

Many individuals who are blind or have low vision may use assistive devices such as screen readers and enlargement utilities to help facilitate computer access. Some types of software programs and/or computer monitors may be incompatible with these devices. They may not provide or support applications that allow the user to set or adjust display options such as color depth, color profile, brightness, resolution, contrast, or icon size.

Blindness

An individual is termed legally blind when their visual acuity is 20/200 or worse after correction, or when their field of vision is less than 20 degrees in the best eye after correction. In 2001, the American Foundation for the Blind reported 1.3 million Americans are legally blind. Among young adults age 18-44, 2.4 percent or 2.6 million persons reported blindness in one or both eyes or reported trouble seeing even when wearing glasses or contact lenses (Adams, Hendershot, & Marano, 1999).

In distance education, two specific areas, visual and audio output, cause difficulty for individuals who are blind:

Visual output difficulties include:
- Images lacking sufficient description;
- Charts and graphs;
- Diagrams;
- Maps;
- Anatomical sketches;
- Architectural/structural models;
- Overhead transparencies and color-coded displays.
Audio output difficulties include:
- Audio information that cannot be easily accessed and replayed at a later time;
- Videotapes;
- Televised presentations;
- Ambiguous descriptions of mathematical formulas and equations;
- Descriptions that require visual memory. (Individuals who are blind from birth will not have a visual memory.)

Individuals who are blind access information in several ways. These may include using:

Refreshable Braille (see Image 7) display that prints screen text line by line.

Image 7: Symbol for printed material available in Braille
Computer equipped with screen reader software or talking word processor that translates and then reads with a synthesized voice text material.
Text-only browser such as Lynx, or simply turning off the graphics-loading feature of a graphical browser such as Internet Explorer.
Speech recognition program, also called voice recognition, that allow giving commands and entering data using one's own voice.
Alternative media such as audiotapes, Braille printouts, electronic text, tactile drawings, and audio descriptions.

Screen Readers

Since the Internet tends to be graphic-based, individuals who are blind or have low vision must rely on a variety of assistive technology and devices to help them access online information. Web-based content created without knowledge of how screen readers operate can make comprehension difficult. Screen readers rely on punctuation cues for appropriate pauses; therefore, periods should be added after headings, labels and items in a bulleted format. They also will speak all basic text symbols, so using these symbols as decoration or as a subject divider is not recommended. In addition, screen readers pronounce unfamiliar words and spellings (i.e. proper nouns, technical jargon, foreign phrases, acronyms) phonetically so use these judiciously or if web-based, use the appropriate coding in the webpage.

Some aspects of screen reader technology that you should be aware of include:

Materials can be translated into Braille or speech, but regardless of the technology, generally require ASCII text. ASCII (pronounced "askee") is an acronym for American Standard Code for Information Interchange and is a common text language that any type of computer or software can read. It is often used extensively for e-mail text. Bit-mapped images of text do not work.
Some types of programs, plug-ins, and page layouts cannot be used with screen reader technology.
Usually screen reader technology requires a static display to function at an optimal level; thus, there needs to be an option for users to update at their discretion.

Other considerations when designing distance education to be accessible for individuals who are blind or have low visions include:

Users who are blind or have low vision often scan or read material by tabbing through the headings and/or viewing all the links of a document. Design the material with an outline basis and provide meaningful, distinct names for links that make sense when read alone.
Tip: For more information on headings and links, visit Module 9: Web Accessibility for Textual Elements.
Graphics including photographs, drawing and image maps cannot be interpreted unless text alternatives are provided.
Tip: For more information on "alt-text", visit Module 9: Web Accessibility for Images.
Incorporate a "skip navigation" or "skip to page content" link as the first element of each page of a website that, after selection, would direct the user to the essential information on that page. Otherwise, users who are blind or have low vision would have to redundantly navigate, or if using a screenreader, repeatedly hear the navigation, each time a webpage is accessed.
Tip: A "skip navigation link" can be made "invisible" to a sighted user but remain detectable to users of screen readers; an example can found at the top of this page (and every page of this tutorial) just above the logo. For more information, visit skip navigation link -- Why and How?
Java applets and plug-ins such as Macromedia Flash are generally inaccessible to individuals who are blind or have low vision, regardless of the screen reader or browser technology used. Pages that rely on JavaScript are not accessible when using text-only browsers such as Lynx. As a result, computer animations and Java-applet chat rooms may not be accessible.
Tip: For more information on animations, Flash, or Java, visit Module 5: Flash Accessibility and Module 10: Scripts and Java Accessibility.

Image 8: Symbol for Audio Description (AD)
Multimedia, video/teleconferences, performing arts, visual arts, television, video, and film need to be accompanied by Audio Description (AD) (see Image 8) when information is not otherwise made clear by the vocal narrative. This provides the user who is blind or has low vision with concise, objective descriptions of relevant visual elements through narration or live commentary by a trained Audio Describer.

Tip: For more information on audio description, visit Audio Description International (ADI) .

Partial or Low Vision

Even with corrections, the monumental quantity of reading generally necessary in education classes is the most difficult large print (see Image 9) or electronic formats may be required.

Image 9: Symbol for Accessible Print (18 pt or larger)

Individuals with partial or low vision may use magnification software to enlarge screen images, which causes only a small portion of a page to be visible at a time. Poor contrast with text color, inconsistent layout, and cluttered pages can create confusion. Even with enlarged text, individuals with low vision may experience eyestrain, headache, nausea and/or other undesirable effects if required to read a large quantity of material within a constricted period of time. Small to medium-size text, decorative fonts, italics, and single-spaced lines of text are problematic as are formats that have less than 1 inch margins, distracting background, or text overlaying graphic content.

Tip: For more information on text legibility, visit Designing Text for People with Partial Sight (Browse to website)

Color-Blindness

Individuals who have color-blindness face barriers when having to distinguish between colors in order to successfully navigate websites or understand specific content. Approximately 8 percent of men and 0.4 percent of women have color-blindness. Although there are different types of color-blindness, the majority of people with color-blindness have difficulty distinguishing between red and green. Other people with color-blindness have problems with shades of colors. Color perception varies in people who have color-blindness; most can detect black and white accurately.

Three images below (Images 10-12) simulate how the planet Earth looks to individuals with various sorts of color-blindness.

Image 10:
View of the Earth from space

Image 11:
How the Earth looks with a red/green color deficit (deuteranopia)

Image 12:
How the Earth looks with a blue/yellow color deficit (tritanopia)

Tip: For more information on color-blindness, visit Vischeck, tools that check or correct the color of images (Browse to website)

The next page will present information about individuals with learning disabilities.

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