I somehow think that if that applied you to that you would have a slightly different attitude.
Can I assume you are perfect Nick? Neither you nor your parents nor your grand parents need any help at all with anything? Reading glasses maybe ?
If so then you are a VERY lucky boy. lets hope it stays that way
So you cant see to read so you are reliant on brail if its hard copy or a tape recording, or a reader if its a web page.
Lets take the last one of those. The assistive technologies require web pages to be written to agreed standards before they work properly.
If they are not they are therefore excluding 20% plus of their user base who can't use a mouse / read the content do to loss of sight, poor limb mobility, loss of limb etc etc
The whole idea is that we use a technologies to minimise the impact of a disability on people lives.
</rant>