It has been a legal requirement for UK websites to be accessible since 1999. Since then all websites have been expected to make "reasonable adjustments" to ensure their websites accommodate all users regardless of ability, disability.
You can read more about UK law for websites here.
The RNIB Web Accessibility Toolbar (Beta) is a free plugin for Internet Explorer. It is designed to make adjusting certain options within Internet Explorer quicker and easier, using either the mouse or keyboard. Developed by RNIB, the Web Accessibility Tools Consortium (WAT-C) and Jun, the Accessibility Toolbar is a free download and currently in beta version.
Download RNIB Web Accessibility Toolbar (Beta) (Zip file, 782KB)
Once you have downloaded the Zip file, open it and double-click on the file called RNIB_Toolbar.exe to install the toolbar onto your computer.
The above information has been provided by the Royal National Institute of Blind People and can be found here.