Machines have been around for ages that you can use to read a book on a large screen with different levels of magnification, it has a tray that you can move around easily and it has a small CCD camera hooked up to a TV screen.
When I was in school in the 80s I used a VisualTech CCD magnifier, in fact they're still around: http://www.visual-techconnection.com/cctvs1.htm
However since most of us have computers these days it's hard to justify having such a bulky device around for books.
So what are the options:
1. Get eBooks and zoom in to your hearts content
(problem: not all books are available in eBook form)
2. Get large print copy of the book you want to read
(problem: same as above, enlargement might be impractical or unavailable [your library mileage may vary])
3. Get a stand alone magnifier device for yer book readin'
(compatible with most books and sidesteps copyright issues)
I can see how people think that computer + webcam + tray = book reader, so I'm interested to see if anyone out there in candyland has found a good setup for this.
But yes, this is a thing that visually impaired people have to deal with that so far only seems to have been solved by a handful of companies.