Hyper text Mark-up Language
The Hyper Text Mark-Up Language (HTML) is comprised of a series of different elements such as titles, images and hyper links. HTML protocol provides a flexible and easy medium that can be used to produce a wide array of different kinds and styles of documents.
In the early days of the internet, most browsers such as Lynx were text only. Thus disabled individuals, many for the first time, had access to information from around the world. However, graphical browsers and multi-media features and the freedom by authors to create documents began to limit the sites that were readily accessible for some such as blind and visually impaired people.
When using HTML code web designers must be aware that those who use screen readers are gaining the information one piece at at time through their sense of hearing (serial sense). This is very different from the way sighted individuals gain information from a printed page. Individuals without vision problems can scan the page and understand the structure as a whole. (parallel sense)
The HTML writers can assist visually impaired by presenting an outline of the structure at the beginning of the page, where the screen reader begins. In addition, they should include important hints along the way.
Screen readers can only handle text. Pictures convey vast amounts of information that is inaccessible to screen readers. This leads to serious problems at sites where all the textual information is contained in graphical form.
To deal with this problem websites use an Alternate Text (ALT Text). This is a very brief description of the image. This text is displayed in place of the image when the image loading has been turned off.
Labels (short text groups placed just after an image in the document) can also be used to help everyone understand the image.
Another solution to the problem with graphics is to use a "Text Only" version of a Document. This is a parallel page that can be accessed by users who are unable to make use of the information contained in an image. This text version should include all the same functionality and content as the original page.
Text is the most accessible and widely used medium for conveying information since it can be readily interpreted by screen readers, braille displays, printed out, etc.
However, authors must be careful about the way they format their pages because screen readers do not always alert users to line breaks, new paragraphs, new pages, centering or spacing used by sighted individuals to process and comprehend printed text.
For example, sighted people would have no problem understanding that the script at the bottom of the page, detached from the main text, is a footnote. However, the screen reader would read right on through causing confusion for the reader.