Katie Cunningham is the author of the Accessibility Handbook (O’Reilly Media). You can find Katie at The Real Katie. She is a Python developer for Cox Media Group, and lives in Washington, DC with her husband and two children.
As an accessibility advocate, I get quite a few business owners and web developers who insist that they don’t have any disabled users or customers. I ask them if they’ve ever done a survey, just to see, and the answer is always no. Why, then, are they so certain that there’s no disabled people using their product? Though I’ve gotten some horrifying responses to that question (one insisted his site was too ‘cool’ for people with disabilities), most boiled down to one thing: statistics. They believed that there were simply so few disabled people in the world that, statistically, it was highly probable that they had no disabled users.
And they couldn’t be more wrong.
The idea of the disabled being a small number usually begins with the misconception that web accessibility is all about the blind. Though many of the efforts towards an accessible web aim at the visually impaired, there’s actually more to it than that. Accessibility actually covers four groups:
- The visually impaired
- The physically impaired
- The hearing impaired
- The cognitively impaired
Already, that swells the number of people who are covered by accessibility. Let’s take the groups one by one.
The Visually Impaired
This group isn’t just about the blind. It’s related to anyone that has trouble with their vision. A person in this group may need glasses in order to see their computer screen, or may be color blind. An estimated 7.9 million people in the US have vision that can’t be corrected to be able to see newsprint. 8.3 million are blind in one or both eyes. 7% of all US males have some sort of color blindness, which can make items like infographics or themes with poorly chosen colors difficult to use. That’s 10 million men in the US.
The Physically Impaired
This category also covers a wide range of people. Some may have limited use of their limbs. Cerebral palsy, just one of the conditions that can cause this, currently affects 800,000 in the US. Arthritis, which can cause issues in a user’s joints, affects 50 million.
This can also cover those who have completely lost the user of their limbs, such as those with progressive diseases like muscular dystrophy (50,000), amputees (41,000 report amputation of the hand or arm), or the paralyzed (5.6 million).
The Hearing Impaired
The hearing impaired isn’t just limited to the Deaf community (which numbers around one million people). It’s often assumed that if a person is able to wear a hearing aid, that their hearing is fixed, just like someone who wears corrective lenses.
Hearing aids and hearing loss isn’t that simple, though. A person can be missing certain tones, making speech difficult to understand. Besides that, hearing aids many times over-emphasize the wrong sounds My father-in-law often turns his off in crowded settings, complaining that he can hear the people across the restaurant, but not the people at his table.
36 million people in the US report having hearing loss.
The Cognitively Impaired
One of the newer groups under the accessibility umbrella, this group has become more vocal in the past few years. Those with dyslexia and ADD or ADHD have begun to press for a less busy Internet, one where ads don’t distract them to the point of being unable to use a site, or where proper contrast is used, rather than the more artistic combinations of light text against an only slightly lighter background.
Approximately 9 million people in the US have ADD or ADHD. 40 million have been diagnosed with a form of dyslexia.
And… Everyone Else
One side of accessibility that most people forget is that anyone, at any time, can suddenly be under the umbrella of the disabled. It could be as simple as leaving your headphones at home the day you have to do some video training at your desk. It could be an injury to your dominant hand, making navigating websites and typing quickly impossible. You can forget your glasses at home. You might be on a painkiller and find yourself having to navigate your insurance company’s online forms.
Or it can be time.
As we age, we start to fit into the above categories. Our hearing might go, or our vision. We might develop arthritis or Parkinson’s, hurting our ability to mouse and type. We might even develop dementia or Alzheimer’s, where our cognitive abilities slowly fade.
So, how many disabled users do you have? More than you think.
 I use US statistics for all my numbers. World statistics can be difficult to obtain. Some countries don’t collect data on all conditions, while others have a higher or lower prevalence of some conditions.