Have just been swimming at my local leisure centre.
When I arrived the woman at the desk said "are you registered disabled?" to which I replied "yes" and she said "oh, well in that case you go in free.
Now. I made my way to this leisure centre entirely independently. on a bus/down the busy high street - not with a dog but a cane as can't take the dog into the pool! 
I am a stronger/better swimmer than most people I know, can easily swim 80 lengths in an hour. Entirely capable of using the pool the use of which I was paying for.
Were I going to an exhibition of visual art I could quite see the point of not paying for it since I can't see it.
But I don't see why disability automatically equals free access purely because it's disability. That's hardly equality is it?