
Making your teaching inclusive from The Open University site has a wealth of resources on accessibility and is a good place to start if you want to find out about equipment that could help your students use the computers independently. selecting the right keyboard ( top of the page )
mouse options (end of the page)
The videos just show you the options with no explanation but the text has links that explain the equipment in further detail.
for example:
where more information about trackball products can be found.