The hits just keep on coming from the Filament Group. Here Scott shares a really clever technique for creating an image magnifier using the sizes attribute of the img element.
The Government Digital Service have published the results of their assistive technology survey, which makes a nice companion piece to Heydon’s survey. It’s worth noting that the most common assistive technology isn’t screen readers; it’s screen magnifiers. See also this Guardian article on the prevalence of partial blindness:
Of all those registered blind or partially sighted, 93% retain some useful vision – often enough to read a book or watch a film. But this can lead to misunderstanding and confusion