Understanding Accessibility

There are many different kinds of disabilities, but for the purposes of web accessibility, the most relevant types are those that affect the eyes, ears, hands, and brain. Some examples include:

  • visual disabilities, such as
    • color blindness
    • low vision or blindness
  • deafness
  • physical disabilities that affect motor function
  • cognitive disabilities related to
    • memory
    • attention
    • problem-solving
    • text processing
    • math processing
    • visual processing
    • literacy
  • seizure disorders

All of these disabilities affect interactions with digital products and services in different ways. In this section we cover best practices for designing with these disabilities in mind.


Assistive Technology

Assistive technology is any piece of equipment, product, or system that people with disabilities use to aid in doing a certain task. Common examples include wheelchairs, hearing aids, crutches, and even glasses.

Understanding how assistive technologies work is key to designing digital products that integrate with them successfully. Below are some examples of assistive technologies that people with disabilities use to access the digital world.

Screen Readers

Screen readers—software that reads a screen’s contents out loud—are the assistive technology most commonly associated with web accessibility. People use screen readers by navigating through page content using touch gestures or keyboard commands. Screen readers are used by members of the blind and low vision community, as well as people with learning disabilities and limited literacy.

Watch the screen reader demonstration below to get a better idea of how they work.


Apple’s built-in screen reader software Voiceover is a popular tool for Mac and iOS. It’s free, and you can use it to see how well your own digital products translate for people using screen readers.

Read more about screen readers in the City’s Screen Reader Testing Guide.

Other Technologies

Other popular assistive technologies include screen magnifiers and voice control technology. Screen magnifiers allow people with low vision to enlarge content on a screen, and can also be used to change background and font colors for better contrast. Voice control technology, a popular tool for people with motor function disabilities, allows users to control devices using voice commands.