GSA Government-wide Section 508 Accessibility Program

Building and Buying Accessible Software | Lesson: Disabilities and Accessibility

In this lesson, you'll learn about how accessibility affects persons with disabilities.

When you?re finished with this lesson, you should be able to:


  • Identify how E & IT accessibility affects persons with disabilities.
  • Identify the types of disabilities addressed by Section 508.
  • Identify the types of assistive technology used by persons with disabilities.


Image of a magnifying glass, a keyboard, and random HTML code. 


Section 508 of the Rehabilitation Act was intended to remove barriers in Electronic and Information Technology (E & IT) for all types of disabilities. Although Section 508 does not define accessibility, it does provide a baseline for as high an inclusion of persons with disabilities as possible.

While most people think accessibility refers to accessing information on the Web, E & IT accessibility also includes a person's ability to use:


  • Intranet.
  • Computers.
  • Telephones.
  • Copiers.
  • Printers.
  • Fax machines.
  • Kiosks.


 a keyboard, a person using a copier, a laptop computer, and a fax machine. 


Think about how you use technology every day. Would you be able to do your job if you were unable to use the computer, the telephone, the copier, the printer, or the fax machine? As a society, we have embraced technology. Most people can hardly conceive of life without it.

However, not everyone can reap its benefits. People with disabilities cannot participate fully because much of the technology is not designed for accessibility.

Inaccessible design creates a digital divide, which blocks some people from taking part in everyday activities and working in an e-environment.

Accessible design allows as many people as possible to use technology regardless of disability, age, or functional limitation.

Photo of a man using an ergonomic keyboard. 


There is growing awareness for the need for accessible design. In 2000, the World Health Organization estimated that there were 500 million persons with disabilities worldwide - nearly 10% of the world population.

In the US, 54 million people, 20% of the population, have a disability.

In addition, as people are living longer and the population ages, the number continues to grow. If you add persons with temporary disabilities due to accidents or illness, it's easy to understand why accessibility is an important issue.

 a man on a TTY, a man in a wheelchair, a woman using a ramp, and a man walking with a white cane. 


E & IT is often evaluated for its usability and accessibility. Though the terms are often used interchangeably, there is a difference. Even if the technology is "accessible", there may still be serious usability problems that make it equally difficult for any person, disabled or non-disabled, to use it.

Usability focuses on how intuitive and easy it is for all people to use. Usable designs are consistent and simple to learn to use. Usability and accessibility often go hand-in-hand.

Accessibility is determined by how barrier free the technology is. Accessibility problems are those that make it more difficult for persons with disabilities to use an application or service than for a non-disabled person.

The key to accessibility is that it should be easy for everyone to use, including persons with disabilities.

Photo of a man sitting at a computer throwing his hands up in frustration. 


Persons with disabilities may have difficulty perceiving or processing some types of information. Imagine trying to surf the Web with the monitor turned off, or with the mouse disconnected. For those who are blind or who have motor disabilities, these limitations are real. They may be unable to use common input devices, such as a keyboard or mouse, and often have to rely on special assistive technology (AT) devices.

 a man using a TTY and a blind man working at his computer. 


Section 508 addresses accessibility issues for persons with these types of disabilities:









Photo of a blind man working at his computer.  His dog sleeps next to the desk. 


To provide maximum accessibility to all users, the section 508 guidelines specify functional performance criteria that essentially define the "spirit" of the law. These criteria, listed in Subpart C of the Access Board standards, apply to all subcategories of the Technical Standards. They require all E & IT products and services to be fully operational without requiring users to have:


  • Vision or visual acuity greater than 20/70.
  • Hearing.
  • Speech.
  • Fine motor control or limited reach and strength.


Alternatively, the product or service may be designed to compatibly work with the assistive technology used by persons with disabilities.

Photo of a man who is using a wheelchair sitting at a computer. A woman is standing near him. There are other computers in the background. 


Persons with disabilities commonly use assistive technology (AT) devices. AT enables a person with a disability to provide inputs and perceive outputs.

AT plays an important role in providing access. However, it is only part of the solution for accessibility. E & IT must be designed to communicate with various types of AT devices. Accessibility problems occur if designers fail to do this when it is possible.

A man using a breathe control device to operate his computer. 


To access information persons with visual disabilities may use:



Screen Readers
Refreshable Braile
Voice Recognition
Sceen Magnification
High Contrast Color



  a man walking with a white cane and a blind man wearing a headset working at his computer. 


Although much of the internet is text or graphics, persons with hearing disabilities still have accessibility issues. Increased use of streaming audio and video means that a person with a hearing disability may not be able to access information. Captioning for all audio content increases accessibility.

Persons with hearing disabilities use AT that includes:






Photo of a man using a tty. 


Mobility disabilities, whether permanent or short-term, limit a person?s ability to use a mouse. Since manipulating a mouse cursor can be laborious, persons with mobility impairments need features that provide keyboard access. They also need to be able to skip repetitive navigation links and access content more directly.

Persons with mobility disabilities typically use AT that includes:


  • Keyboard access.
  • Breathe control devices.
  • Retinal scanning devices.
  • Voice input/recognition.


Photo of a man using a retinal scanning device to operate a computer. 


Accessible design benefits more than just persons with disabilities. Have you ever taken advantage of a curb cut while riding a bike or pushing a baby carriage? Although curb cuts and building ramps were installed to provide access for people in wheelchairs, those with difficulty navigating steps also take advantage.

The key to accessibile design is that it should be easy for everyone to use, including a person with a disability. Design that is more accessible:


  • Creates new opportunities for persons with disabilities.
  • Creates a less hostile work environment for persons with disabilities.
  • Often reduces fatigue and increases speed for all users.
  • Broadens the audience you can reach.


Photo of a woman in a wheelchair going up a ramp. 

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