Understanding Disabilities and Barriers

There are many reasons why people may have disabilities. For instance, some people are born with disabilities, while others may acquire a disability as a result of aging, an accident, or disease.

Websites and applications designed for people with a broad range of abilities benefit everyone, including people without disabilities. It is, therefore, important to consider the broad diversity of functional needs rather than to categorize people according to medical classifications. To begin to understand these needs, one must understand the nature of the disability. The following is a basic overview of the broad categories of disabilities and some examples of access barriers that people with these challenges may experience.


People who are Deaf or Hard of Hearing People may be completely deaf or have some hearing. Those who can hear sounds may not be able to hear enough to understand speech - especially when there is a background noise. Some people who are Deaf or Hard of Hearing may choose to use amplification devices, such as hearing aids, cochlear implants, or other assistive technologies.

Examples of barriers for people who are Deaf or Hard of Hearing:

  • Audio content, such as videos with voices and sounds, without captions or transcripts.
  • Media players that do not display captions and that do not provide volume controls.
  • Web-based services, including web applications, that rely on interaction using voice only.
  • Lack of sign language to supplement important information and text that is difficult to read.

Cognitive, Learning, and Neurological

Cognitive, learning, and neurological disabilities involve neurodiversity and neurological disorders, as well as behavioral and mental health disorders that are not necessarily neurological. Neurological disorders may affect any part of the nervous system and impact how well people hear, move, see, speak, and how well they understand information. Cognitive, learning, and neurological disabilities do not necessarily affect the intelligence of a person.

Examples of barriers for people with cognitive, learning, or neurological impairments:

  • Complex navigation mechanisms and page layouts that are difficult to understand and use.
  • Complex sentences that are difficult to read and unusual words that are difficult to understand.
  • Moving, blinking, or flickering content, and background audio that cannot be turned off.
  • Web browsers and media players that do not provide mechanisms to suppress animations and audio.
  • Visual page designs that cannot be adapted using web browser controls or custom style sheets.


Physical disabilities (sometimes called “motor disabilities”) include weakness and limitations of muscular control (such as involuntary movements including tremors, lack of coordination, or paralysis), limitations of sensation, joint disorders (such as arthritis), pain that impedes movement, and missing limbs.

Examples of barriers for people with physical disabilities:

  • Websites, web browsers, and authoring tools that do not provide full keyboard support.
  • Insufficient time limits to respond or to complete tasks, such as filling out online forms.
  • Controls, including links with images of text, that do not have equivalent text alternatives.
  • Inconsistent, unpredictable, and overly complicated navigation mechanisms and page functions.


Speech disabilities include difficulty producing speech that is recognizable by others or by voice recognition software. For example, the loudness or clarity of someone’s voice might be difficult to understand.

Examples of barriers for people with speech impairments:

  • Web-based services, including web applications, that rely on interaction using voice only.
  • Websites that offer phone numbers as the only method of communicating with the organization.


Visual disabilities are wide-ranging and can be defined in several ways. For some, a visual disability is defined as a “decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses or medical treatment.” Other definitions include “significant vision loss” (total or near-total blindness), “legally blind” (central visual acuity of 20/200 or less), and there are no generally accepted definitions for “visually impaired,” “low vision,” or “vision loss.” Visual disabilities can be a result of disease, trauma, or congenital or degenerative conditions. Some people may be completely color-blind or lack sensitivity to certain colors and some may be hypersensitive to bright lights or bright colors. These variations in perception of colors and brightness can be independent of visual acuity.

Examples of barriers for people with visual disabilities:

  • Images, controls, and other structural elements that do not have equivalent text alternatives.
  • Text, images, and page layouts that cannot be resized, or that lose information when resized.
  • Missing visual and non-visual orientation cues, page structure, and other navigational aids.
  • Video content that does not have text or audio alternatives, or an audio-description track.
  • Text and images with insufficient contrast between foreground and background color combinations.
  • Websites and applications that do not provide full keyboard support.

It is important to remember that some people may have any combination of the above described disabilities at the same time. This is commonly called comorbidity. This will be an important factor to be considered when making decisions about accessibility in product development and the flexibility of the solutions implemented.

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