WebAIM (Web Accessibility in Mind) is committed to improving the Web for disabled people.
One service the site offers is a screen reader simulation which will give you an idea of how a blind person might use the Web. Other services include a distractibility simulation, which shows how a person with a cognitive disability might see the Web, and a low vision simulation.
WebAIM has provided comprehensive Web accessibility solutions since 1999. These years of experience have made WebAIM one of the leading providers of Web
accessibility expertise internationally. WebAIM is a non-profit organization within the
Center for Persons with Disabilities at Utah State University. The mission is to expand the potential of the Web for people with disabilities by providing the knowledge, technical skills, tools, organizational leadership strategies, and vision that empower organizations to make their own content accessible to people with disabilities.
Click this link to visit http://www.webaim.org.