Ways that refreshable braille displays are covered in WCAG 2.1:
The braille writing system uses raised dots to represent characters such as letters, numbers, and punctuation. This system makes literacy possible for many people with visual impairments Roughly 10 percent of legally blind people in the U.S., or 130,000 people, are able to read braille as reported by the National Federation of the Blind.
Assistive technologies such as refreshable braille displays have enabled computer users with visual impairments to access the internet independently. In order to adequately serve braille readers then, web developers and designers must evaluate the compatibility of their site with refreshable braille displays.
What Is a Refreshable Braille Display?
A refreshable braille display, also known as a braille terminal, is a particular type of assistive technology. Assistive technology is a system or piece of equipment intended to assist people with disabilities. The display is composed primarily of a rubber strip with pins that can be raised or lowered in order to translate the text displayed on a computer screen into braille.
Users with visual impairments can use the display to read the braille text line by line, refreshing it when they come to the end of the strip. This allows them to understand, and successfully navigate, different websites and applications.
Popular refreshable braille displays include Freedom Scientific’s Focus Blue displays and the Brailliant displays from Boundless. Because braille readers require special manufacturing and are intended for a niche market, they often cost several thousand dollars or more. However, projects such as the Orbit Reader 20 are seeking to cut the price of braille displays to only several hundred dollars, making them much more accessible.
Refreshable Braille Displays and WCAG
As the most widely recognized standard of web accessibility, the Web Content Accessibility Guidelines (WCAG) are familiar to thousands of accessibility experts, web developers, and web designers. WCAG 2.1, the most recent version of the WCAG standard, contains several recommendations that are relevant for braille displays:
- 1: Most non-textual content on a web page should have a “text alternative” that communicates their concepts and ideas. For example, images should have captions that describe the content of the image. This enables users with visual disabilities to receive the full slate of information that sighted users receive as well.
- 3.1: Information that is conveyed through presentation, such as the use of green and red colors to designate “available” and “not available,” must be available through the text or code of the web page as well. This guideline means that users with visual disabilities are not put at a disadvantage when using braille displays by missing cues that are only available visually.
- 1.1: Assistive technologies such as braille displays are able to “programmatically determine” the human language that the web page is written in. This allows a braille display to correctly parse words and characters from foreign languages.
What Web Developers Should Know About Refreshable Braille Displays
In accordance with the WCAG recommendations above, web developers should understand the following tips:
- The alt HTML attribute is used to provide captions for images and other non-textual context. For example, the HTML code <img src="pancakes.jpg" alt="A stack of pancakes"> provides alternative text for a photograph that you posted of your breakfast this morning.
- The lang HTML attribute is used to specify the natural language of a given web page or passage. For example, the HTML code <html lang="en"> designates that the page is written in English.
Braille displays and screen readers are vitally important assistive technologies for users with visual disabilities, giving them equal access to websites and other digital media. To learn more about how to make your website more accessible, visit the Bureau of Internet Accessibility blog or contact us for a free consultation.