Accessibility: Is this ONLY for a subset of the world population?

I was doing a course on Udacity where I learnt that accessibility and the ways in which we use our laptops and gadgets need not be limited to the differently-abled. We all could face a limitation of some sort or the other, temporary or permanent in our lives. This got me thinking more on the topic. I did a bit of lookup on Google for some facts around this.

Here are the 3 that I found most relevant:

Approximately 500,000 people in America end up with eye injuries as a result of preventable accidents.

A sizeable percentage end up losing their vision too. In addition to this medical concerns like conjunctivitis to larger ones like cataract and glaucoma could also be reasons for temporary and permanent loss of vision. The people we are talking about were previously part of the normal pool, but end up in a visually impaired situation. A loss of vision however temporary it may be also is a reason for concern. Don’t accessible solutions make more sense considering these?

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Accidents resulting in paralysis

People in the age group of 16–30 constitute half of the spinal cord injury patients. The location of the injury determines how big the impact is. It worsens as the injury is higher up the spine. Paraplegia, paralysis of lower limbs is the effect of injuries to the middle section of the spine. An injury towards the neck could result in paralysis of all limbs, quadriplegia. Do we think of such scenarios when we discuss voice enablement for using our apps/websites?

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Effect of age on dexterity

Research has shown that as age increases we lend to go lower on dexterity. As age progresses the muscle movements are slower, less coordinated and a bit out of control. Are we saying they also belong to the sub-set now? Do we really place a bigger button or consider the placement of buttons to make the app easier to use even if the person is a bit heavy-handed?

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These are the more serious accidents, what about the simpler ones that leaves your hand fractured. Can you continue use your phone with just as much ease with one hand while your other hand stays in the cast for 3 weeks? Even gloves don’t allow your touch panel to be useful anymore, forget the app. Same goes for everyday situations like accessing your phone while say, cooking, or balancing a heavy bag of groceries on one-hand. Do these get considered in improving the overall user experience for an app/website?

Well like the course also taught me, not all apps or websites are meant for all kinds of people or situations. And we may not always be a 10/10 in fulfilling all that is required.

I came across an informative article about ios apps for people with special needs in terms of using their smart phones. There are loads for android devices too. Website accessibility norms are pretty much in place and much more advanced that those for mobile-apps.

I am yet to understand, what is the exact definition that would categorize a persona as “Accessibility Relevant”? Does it make sense to have configurable settings in the app to suit the needs of different people? Eg: Bigger buttons for senior users, enable voice recognition for visually impaired etc? Is this already the norm? What are your thoughts on this?