508 Web Accessibility


Designing accessible web pages is a challenging task with the ever evolving world of web design. With every new advance to the user comes the possibility of accessibility being compromised or broken. Web interfaces with interactive content usually pose problems fo the visually impaired.  

Visually impaired individuals use software that either magnifies the screen or provides speech and Braille output of the site's contents. Visual impairment, or blindness, is actually a continuum ranging from possessing full sight to being totally blind (without any sight or light perception).

Screen Magnification Users

Low-vision users make up the first group of users that rely on screen magnification. They may just use the built-in magnification of the web browser to adjust the font to the size that they can see. These users may need to magnify the screen two to three times its size to focus in on the text. Also persons who are color blind may not be aware of changes in the color scheme which could be problematic if color is being used as an element in the site's navigation.

For these users a site that is clearly laid out with easily identifiable sections of the page will help when they magnify the screen. A cluttered interface may confuse the user who is using screen magnification. Remember that magnifying the screen two times limits the user to view one fourth of the screen. A person using three times the magnification will only see one ninth of the original screen.

Having a cluttered interface will also impact a person with a learning disability. These individuals may not be able to select the proper section of the web site that they are looking for. They may get lost in the busy interface. Everyone can benefit from a straight forward interface that is easy to navigate. This makes the site easier for all to use and appreciate.


Screen Reader Users

The next group of visually impaired individuals are those who rely on screen readers to navigate the Internet. These individuals may have some usable vision; however, they may find that using a spoken interface is much faster for them to navigate websites. For this group it is better to consider them limited to having no usable vision to navigate the website. In other words it is better not to assume that the person can get sighted assistance or have some vision to overcome some of the inaccessible parts of the site.

The main considerations for this group of users is using clearly identified web elements to design the website. Screen readers all use web elements to navigate the webpage with the screen reader. Elements like: headings, lists, tables, form fields, combo boxes and buttons. Links and images can also be used to navigate the page, if they are properly labeled. A screen reader user will use these different elements to navigate the website. He or she can move forward or back by headings or any other of the above mentioned elements.

It is important to remember that the screen reader user cannot see the layout of the page and digest the webpage by just looking at it. The person must use the elements to get a sense of the site and its layout.

Some things to keep in mind when using the elements. First each element must be given the proper label or alt tag in the case of an image. A very common problem that occurs on the internet is having form fields with no label. What ends up happening is that the screen reader cannot provide the person with the type of field that is being viewed. If the field requires a name the person would not know this by moving to the field. He or she would have to navigate before the field and try to figure out what kind of information the field requires.

Images are also challenging. Sometimes they are also used as a link. Without the proper alt tag the screen reader user would not be able to find the link that is being provided by the image. IF the images are correctly tagged, the screen reader user can get the description of the image and the link that is attached to it.

Another problem that is common on the internet is the misuse of tables. Tables are navigable by screen readers. Where they become cumbersome is when they are used for layout as in some older basic html sites tended to use. The table is harder to navigate for the screen reader user and can be confusing when it doesn’t have any other purpose than just aligning the text. The same can be accomplished now with CSS and other formatting options.

Another concern with tables is nested tables: that is tables or cells within cells. Here the screen reader user can have a very difficult time navigating the table and understanding where they are in the context of the table. It is better to have a clear cell for each element of the table. For example each cell should only contain one button or check box. I have seen sites where a cell may have a button, checkbox and an edit field. This kind of layout can be very confusing for a person relying on a screen reader.

In creating the layout of a webpage it is clearer for the screen reader user to have headings to divide the page into its sections. If each important part of the page has a heading, the person can quickly navigate to each section by moving through the page by headings. Tables and lists should only be used when it is actually organizing information that requires that kind of layout.


Some Considerations

Some areas to consider when creating an accessible website are limitations in the screen reader’s ability to access the information. The content that causes this the most is Flash. Flash is for the most part inaccessible. Some screen readers like JAWS for Windows can access some flash elements: however, for the most part Flash should be avoided, or at the least be backed up with a non-Flash version of the content.

Another challenge that we face on the internet is web pages that use Ajax, JavaScript and other dynamic content. Again Ajax allows for the web designer to do many creative things: however, screen readers may not be able to support this new functionality.

A new standard has been introduced to address these new emerging technologies. It’s called WAI-ARIA. The WAI-ARIA (Web Accessibility Initiative Accessible Rich Internet Applications Suite) is trying to build a bridge for screen readers to access this new rich content in accessible ways. So far JAWS for Windows is one of the screen readers that is supporting WAI-ARIA. Visit WAI-ARIA for more information.


Other Accesibility Websites

Web Content Accessibility Guidelines 1.0

Web Content Accessibility Guidelines 2.0

American Foundation for the Blind

Ten tools for testing web site accessibility

Guidelines on making your site usable for the color blind


Screen Readers

On the Windows platform there are JAWS and Magic from the company Freedomscientific. JAWS is a screen reader and Magic is the magnification program they offer. Both programs work well together and possess the largest market share on the Windows platform. Window-eyes from GW Micro is a screen reader that is less popular than JAWS, but is also a very good screen reader for Windows. Zoom Text is the other magnification program for Windows that is produced by AI Squared. 

The Macintosh OS has built-in accessibility that can be found in the universal access preference panel. The Mac provides Voice Over as a screen reader and Zoom for magnification. The Mac OS has a big advantage because it provides accessibility right in the operating system.All Apple products are designed to be accessible out of the box. iOS devices such as iPhones, iPods and iPads have both Voice Over and Zoom.