Often, decisions and compromises must be made in projects large and small. Experienced decision makers surround themselves with factual data so that they can weigh the benefits and risks of any crucial decision. When it comes to online accessibility, it is important to remember that is not just about "disabled" users, it's about all users - "disabled" is a label that many people do not want or feel applies to them.

A study by Microsoft in 2004 showed that among adult computer users in the United States:

  • 1 in 4 has a vision difficulty
  • 1 in 4 has a dexterity difficulty
  • 1 in 5 has a hearing difficulty

The Microsoft Survey also found that 16% of users have a cognitive difficulty or impairment, and few (3%) have a speech difficulty or impairment.

Actual study numbers show:

  • 17% (21.9 million) of computer users have a mild visual difficulty or impairment, and 9% (11.1 million) of computer users have a severe visual difficulty or impairment.
  • 19% (24.4 million) of computer users have a mild dexterity difficulty or impairment, and 5% (6.8 million) of computer users have a severe dexterity difficulty or impairment.
  • 18% (24.0 million) of computer users have a mild hearing difficulty or impairment, and 2% (2.5 million) of computer users have a severe hearing difficulty or impairment.

(Source: Study Commissioned by Microsoft Corporation and Conducted by Forrester Research, Inc. - www.microsoft.com/enable/research/computerusers.aspx)

Other statistics can also provide a strong argument for ensuring your on-line presence is accessible:

  1. 12.8 percent of adults (21-64) are disabled in some way. Bjelland, M.J., Erickson, W. A., Lee, C. G. (2008, November 8). Disability Statistics from the American Community Survey (ACS). Ithaca, NY: Cornell University Rehabilitation Research and Training Center on Disability Demographics and Statistics (StatsRRTC). Retrieved April 7, 2009 from www.disabilitystatistics.org
  2. 8 to 12% of males of European origin have a color deficiency. Accessibility and the Web
  3. 5.5 million people have obstructed vision because of cataracts. - Statistics on Blindness and Blinding Diseases in the United States
  4. 4.2 million people have impaired vision because of corneal dystrophies. - Statistics on Blindness and Blinding Diseases in the United States
  5. Worldwide, 42 million people are blind. - Statistics on Blindness and Blinding Diseases in the United States
  6. Approximately 17 percent (36 million) of American adults report some degree of hearing loss - NIDCD Health Information
  7. Only 1 out of 5 people who could benefit from a hearing aid actually wears one - NIDCD Health Information
  8. 5% of people have javascript turned off - W3 Schools
  9. Internet Explorer 6 still has a 17% browser share - W3 Schools

Disability Statistics for the U.S. by Sex and Age

U.S. civilian non-institutionalized population 5 years and over - there are about 49.7 million people (about 19 percent) who are considered "disabled", again numbers that are consistent with the Microsoft survey.

Population Both Sexes Male Female
 
Population 5 years and over 257,167,527 124,636,825 132,530,702
Population 5 years and over With a Disability 49,746,248 24,439,531 25,306,717
Population 5 years and over Percent with a Disability 19.3% 19.6% 19.1%
 
Population 5 to 15 years 45,133,667 23,125,324 22,008,343
Population 5 to 15 years With a Disability 2,614,919 1,666,230 948,689
Population 5 to 15 years Percent with a Disability 5.8% 7.2% 4.3%
 
Population 16 to 64 years 178,687,234 87,570,583 91,116,651
Population 16 to 64 years With a Disability 33,153,211 17,139,019 16,014,192
Population 16 to 64 years Percent with a Disability 18.6% 19.6% 17.6%
 
Population 65 years and over 33,346,626 13,940,918 19,405,708
Population 65 years and over With a Disability 13,978,118 5,634,282 8,343,836
65 years and over Percent with a Disability 41.9% 40.4% 43.0%

(Source: U.S. Census Bureau. Census 2000 Summary File 3. Retrieved May 20, 2005, from American FactFinder http://factfinder.census.gov and tabulated by accessible-systems.com)

...and don't forget...

These numbers rely to a certain extent on identified or self-identified users-with-impairments. Many people will have user requirements that most people often do not think of as impairments or disabilities; however accessible content delivery benefits these people too - be it the ability to enlarge the text on the screen (visual impairment), to having clear, easy and user-friendly site navigation (cognitive impairments).

The anonymity of internet usage makes tracking users and user requirements for your particular web site difficult to impossible. But by looking at general population numbers and statistics it should become very clear that between 20% and 25% of the average web site user-base will benefit from ensuring that accessible design and development techniques are incorporated into your current or next-generation web property.