Editing Computer accessibility (section)

== Accessibility options for specific impairments ==
[[File: BBC News web accessibility demo.jpg|thumb|[[BBC News]] shown in 'desktop mode,' with accessibility links at the top. The screenshot is taken from Windows Mobile.{{Update span|date=December 2023}}]]
[[File:Single switch onscreen keyboard.jpg|thumb|A single-switch [[assistive device]] that enables the user to access an [[on-screen keyboard]]]]

=== Cognitive impairments and illiteracy ===
The biggest challenge in computer accessibility is to make resources accessible to people with cognitive disabilities—particularly those with poor communication and reading skills. For example, people with learning disabilities may rely on proprietary symbols and identify particular products via the product's symbols or icons.  Unfortunately, copyright laws can limit icon or symbol release to web-based programs and websites by owners who are unwilling to release them to the public.

In these situations, an alternative approach for users who want to access public computer-based terminals in [[libraries]], [[Automated teller machine|ATMs]], and information kiosks is for the user to present a token to the computer terminal - such as a [[smart card]] - that has configuration information to adjust the computer speed, text size, etc. to their particular needs. 

This concept is encompassed by the [[Comité Européen de Normalisation|CEN]] standard "Identification card systems – Human-machine interface".<ref>CEN: [http://www.cen.eu/cen/Sectors/TechnicalCommitteesWorkshops/CENTechnicalCommittees/Pages/TCStruc.aspx?param=6205&title=Personal%20identification,%20electronic%20signature%20and%20cards%20and%20their%20related%20systems%20and%20operations Personal identification, electronic signature and cards and their related systems and operations - Structure] {{Webarchive|url=https://web.archive.org/web/20131005012815/http://www.cen.eu/cen/Sectors/TechnicalCommitteesWorkshops/CENTechnicalCommittees/Pages/TCStruc.aspx?param=6205&title=Personal%20identification,%20electronic%20signature%20and%20cards%20and%20their%20related%20systems%20and%20operations |date=2013-10-05 }}.</ref><ref>{{cite web|url=http://www.tiresias.org/research/reports/en1332_4_revision.htm |title=Draft EN 1332-4 Identification Card Systems - Man-Machine Interface - Part 4 : Coding of user requirements for people with special needs |publisher=Tiresias.org |date=2009-11-20 |access-date=2013-07-28}}</ref> This development of this standard has been supported in Europe by [[SNAPI]] and has been successfully incorporated into the Local Authority Smartcards Standards e-Organisation (LASSeO) specifications.<ref>LASSeO: {{usurped|1=[https://web.archive.org/web/20130814090117/http://lasseo.org.uk/papers/130640%20final%20report.pdf Feasibility Studies - Final Report]}}. August 2011.</ref>

=== Visual impairment ===
Since computer interfaces often require visual input and provide visual feedback, another significant challenge in computer accessibility involves making software usable by people with visual impairments.

For people with mild to medium vision impairment, things like large [[Typeface|font]]s, high DPI displays, high-contrast themes and [[icon (computing)|icon]]s combined with auditory feedback and screen magnifying software are very useful. In the case of severe vision impairment such as blindness, [[screen reader]] software that provides feedback via [[text to speech]] or a [[refreshable braille display]] is a necessary accommodation for interaction with a computer.

About 8% of men and about 0.4% of women have some form of [[Color blindness|color-blindness]].<ref>Chan X, Goh S, Tan N (2014). "Subjects with colour vision deficiency in the community: what do primary care physicians need to know?". Asia Pacific Family Medicine. 13 (1): 10. DOI:10.1186/s12930-014-0010-3.</ref> The main color combinations that might be confused by people with visual deficiency include red/green and blue/yellow. However, in a well-designed user interface, color isn't the primary way to distinguish between different pieces of information.

=== Motor and dexterity impairments ===
Some people may not be able to use a conventional [[input device]], such as the [[computer mouse|mouse]] or the [[computer keyboard|keyboard]]. Therefore, it is important for software functions to be accessible using both devices.  Ideally, the software will use a generic input [[API]] that permits the use even of highly specialized devices unheard of at the time of software's initial development. [[Keyboard shortcuts]] and [[mouse gesture]]s are ways to achieve this access, as are more specialized solutions, including on-screen software keyboards and alternate input devices ([[Switch Access|switches]], [[joystick]]s and [[trackball]]s). Users may enable a [[Bounce keys|bounce key]] feature, allowing the keyboard to ignore repeated presses of the same key. [[Speech recognition]] technology is also a compelling and suitable alternative to conventional keyboard and mouse input as it simply requires a commonly available audio headset.

[[User interface design|UI design]] can also improve accessibility for users with motor impairments. For example, [[barrier pointing]] design allows commonly-used functions to require less accuracy to select.

The [[astrophysics|astrophysicist]] [[Stephen Hawking]] is an example of someone with severe motor and physical limitations who used assistive technology to support [[activities of daily living]]. He used a switch, combined with special software, that allowed him to control his [[wheelchair]]-mounted computer using his limited and small movement ability. This personalized system allowed him to remain mobile, do research, and produce his written work.  Prof. Hawking also used [[augmentative and alternative communication]] technology to speak and an [[environmental control device]] to access equipment independently.

A small amount of modern research indicates that utilizing a standard computer mouse device improves fine-motor skills.<ref>{{cite web | url=https://www.science.org/content/article/click-here-improve-your-motor-skills | title=Click here to improve your motor skills | work=Science | date=December 19, 2013 | access-date=23 December 2013 | author=Bohannon, John}}</ref>

=== Hearing impairment ===
While [[sound user interface]]s have a secondary role in common desktop computing, these interfaces are usually limited to using [[Sound effect|sound effects]] as feedback.  Some software producers take into account people who cannot hear due to hearing impairments, [[silence]] requirements, or lack of sound-producing software.  The system sounds like beeps can be substituted or supplemented with visual notifications and captioned text (akin to [[closed captioning]]). Closed captions are a very popular means of relaying information for the Deaf and hearing-impaired communities. Modern [[computer animation]] also allows for translation of content into sign language by means of sign language avatars, such as SiMAX.<ref>{{cite web |url=http://sowartis.com/projects/simax/#1481043240786-c3380c92-a941 |title=SiMAX |author=<!--Not stated--> |date=2018 |website=Sowartis |access-date=22 September 2020}}</ref><ref>{{cite conference |url=https://dl.acm.org/doi/10.1145/2049536.2049557 |title=Assessing the deaf user perspective on sign language avatars |last1=Kipp |first1=Michael |last2=Nguyen |first2=Quan |last3=Heloir |first3=Alexis |last4=Matthes |first4=Silke  |date=October 2011 |publisher=[[Association for Computing Machinery]] |book-title=Proceedings of the 13th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS-11) |pages=107–114 |location=Dundee, Scotland |doi=10.1145/2049536.2049557 |conference=13th ACM SIGACCESS Conference on Computers and Accessibility |url-access=subscription }}</ref>