Reasons for Considering Accessibility

Accessibility should be included as part of your application development process for many reasons:

The potential market is large. There are approximately 49 million people with disabilities in the U. S.; of these people, an estimated 30 million have disabilities that can be affected by the accessibility of computer software. If the international market is included in the totals, the numbers are much higher.
When you build accessible applications, you are not just targeting people with disabilities, but also their family and friends, their coworkers, and their employers. Large organizations today employ people with disabilities and expect their mainstream computer applications to accommodate all members of their staff. Failing to meet the needs of a relatively small group of users can affect sales to a large organization.
Legislation requires employers to make reasonable accommodation for employees with disabilities. The Americans with Disabilities Act affects private businesses with 15 or more employees, and section 508 of the Rehabilitation Act affects the federal government and organizations that receive government funding.
Accessibility is being incorporated into official and international standards for usability, such as ANSI 200.
Many people develop permanent or temporary disabilities through injury or disease. Repetitive stress injury caused by typing or using a mouse is increasingly common in the computer industry, and as the population ages, more people are likely to experience periods of disability. By age 55, a person has a 25% chance of spending a significant period of time with a serious disability, and the chances increase to 75% by age 70.
Accessible design actually improves usability for everyone, not just people with disabilities. It helps make applications compatible with future interface technologies, such as voice recognition. The same techniques that allow applications to be compatible with accessibility aids also help with other forms of application integration, such as compatibility with automated testing tools and other scripting or macro facilities.

Of course, many people believe that accessibility is the right thing to do to allow each individual to live independently and to make his or her maximum contribution to society.