Using aural cascading stylesheets, a combination of visual and aural presentation can help enhance comprehension. Many of these features have the potential to enhance pages for persons with disabilities as well as increase page usability for users in general. Because multiple stylesheet can link to and re-render the same set of web document it is very quick and convenient to offer alternative streams of a web site. Any designer can almost instantly create a large-print, high contrast version of their web site without modifying the corpus of underlying HTML documents. It is a complex and powerful procedural language opposed to the relatively simple CSS rules-based language.
Authors can now keep HTML structure simple, focus on content, and use CSS to embellish design.
But use of CSS does not necessarily equate accessibility. It is still important to ensure that authored pages make sense if viewed with a non-CSS compliant browser. For a web author to put too much formatting control into the stylesheet is dangerous since a reader may opt to use their own CSS or disable them completely. Web pages should be coherent with or without the CSS rules. Likewise, a reader must be aware that there will be some pages that will remain inaccessible no matter what their reader-stylesheet declares.