While this article is mainly focused on issues surrounding the blind subgroup of visually impaired disabilities, it is important to remember that the term disability encompasses a fairly diverse group that needs to be recognized. Even in the visually impaired disability group, there are other types of disability such as low vision. People with low vision can see images but not clearly. Besides visual disabilities, there are also, physical, cognitive, and psychological disabilities that are just as important to the concept of universal access. The World Health Organization in The International Classification of Impairments, Disabilities, and Handicaps defines disability as "any restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being."
The overarching principle when dealing with disability is to help a disabled person to function with the least amount of accommodation possible. Yes, people who have low vision could learn Braille, but then so could those without a visual impairment. How would you feel as a user who was forced to learn a completely tactile method of reading even though you have the ability to see letters with your eyes? Users with low vision need to be respected likewise. They can read text, just not small text. In this case, the accommodation is to make the text larger.
Physical disability has probably gotten the most press of any of the disability types. This is probably what most imagine when they hear the term disability. Even the symbol we use for disability is the wheelchair, a symbol most directly associated with a physical disability. The important thing to remember, however, is that a physical disability may involve any part of the body, not necessarily the legs. People who only have the use of one hand still have to type on keyboards and tie their shoes, but they certainly do not need wheelchairs. It is important to remember, then, that each type of physical disability has its own challenges and specific accommodations.
Cognitive disability is sometimes difficult to see. Whether the result of a head injury sustained in a car wreck, problems resulting from a stroke, or just because a person was born with a disability like mental retardation, this type of disability is fairly common in our population. And accommodations needed by individuals with cognitive disabilities must be specific to meet the needs of that person. One person may need to have text on a screen at a very high contrast because the words get lost if they are on top of a background picture. Others may need to hear the text while they see it to help maintain their focus on the content.
Psychological disabilities are the least understood by the general public. Specific problems that can arise from this group could include decreased frustration tolerance or the lack of ability to maintain concentration. Luckily, by making a web site less frustrating by successful navigation, navigation that facilitates access and ease, the site becomes more accessible to all persons irrespective of a particular disability.
The amount of detail needed to accommodate users with disabilities does tend to make developers worry. However, it is possible to design a site that applies the design concept of universal accessibility, one that accommodates each of the above disability types simultaneously. And the best part, it is a fairly simple concept. Since this article uses blindness as its reference disability, click on "Web accessibility for the visually impaired" for more information on how to make better web pages using the concept of universal accommodation.