People with the following conditions find using websites challenging:
| Disability | Examples | Learn More |
|---|---|---|
| Visual | blindness, low vision, color-blindness | https://webaim.org/articles/visual/ |
| Auditory | deafness, hard-of-hearing | https://webaim.org/articles/auditory/ |
| Motor | slow response time, limited motor control, inability to use mouse/keyboard | https://webaim.org/articles/motor/ |
| Cognitive | learning disability, destructibility, inability to remember, focus on large amount of information (learn more) | https://webaim.org/articles/cognitive/ |
| Seizure & Vestibular | seizures caused by strobing, flickering, or flashing effects, dizziness and nausea caused by movement | https://webaim.org/articles/seizure/ |
People with substantial, uncorrectable loss of vision in both eyes generally use screen readers such as VoiceOver for Mac OS, JAWS for Windows, and so on. Screen readers read aloud a web page based on how the page is structured as markup, which might not reflect how the page is visually laid out. Screen reader users use their keyboard as their primary means of navigating the web. Screen readers can also be used by those who are both deaf and blind. Rather than convert text into speech, screen readers for the deaf-blind convert text into Braille characters on refreshable Braille devices.
The visual acuity of people with low vision varies widely, but, in general, low vision is defined as a condition in which a person's vision cannot be fully corrected by glasses. The most common technology used by people with low vision is screen magnifiers, assistive technology to adjust the page elements' contrast to suit their vision condition. Some people with low vision will change the settings in their operating system and/or browser to not only enlarge the text, but to increase the contrast of the text in relation to the background.
People with color blindness might use assistive technology to transform colors by converting to ones they can recognize. But, you'd better prepare your website assuming they don't use assistive technology.
{% hint style="info" %} See how people with color-blindness see colors. {% endhint %}
Most of people with deafness and hard-of-hearing rely on visual presentation of information. Depending on their severity of hard-of-hearing, they might be able to obtain audio content with some adjustment.
People with physical disabilities rely on keyboard support to activate functionality provided on web pages. To use the Web, people with physical disabilities often use specialized hardware and software such as:
- Ergonomic or specially designed keyboard or mouse;
- Head pointer, mouth stick, and other aids to help with typing;
- On-screen keyboard with trackball, joysticks, or other pointing devices;
- Switches operated by foot, shoulder, sip-and-puff, or other movements;
- Voice recognition, eye tracking, and other approaches for hands-free interaction.
People with physical disabilities may have trouble clicking small areas and are more likely to make mistakes in typing and clicking. Providing large clickable areas, enough time to complete tasks, and error correction options for forms are important design aspects. Other important design aspects include providing visible indicators of the current focus, and mechanisms to skip over blocks, such as over page headers or navigation bars. People with cognitive and visual disabilities share many of these requirements.
The concept of cognitive disabilities is extremely broad, and not always well-defined. In loose terms, a person with a cognitive disability has greater difficulty with one or more types of mental tasks than the average person.
Usually, the best advice to help users with cognitive disabilities is to provide information in multiple formats, with a heavy emphasis on visual formats. Even though most web content suffers for a lack of visually-enhanced communicative methods, the take-home message is that no one method is sufficient by itself. Supplement the information with multiple modes and methods of communication.
Some people are susceptible to seizures caused by strobing, flickering, or flashing effects. This kind of seizure is sometimes referred to as a photo-epileptic seizure because it is caused by pulses of light (hence the prefix "photo") interacting with the eye's light-receptive neurons and the body's central nervous system.
Even if an animating or moving object does not cause a seizure, it may cause nausea or dizziness in some people.
The following items can result in difficulties for users with vestibular disorders:
- High contrast graphics with tight parallel lines.
- Animated scrolling that lasts longer than perhaps 1/4 second.
- Parallax or reverse parallax - simultaneous foreground and background scrolling in different directions or at different speeds.
- Moving images beneath static text.