What accessibility support exists for low vision?

To the Group:


One thing that we have proved is that zoom is not accessibility support. My
work on reading has shown that zoom is very possibly the worst user
interface in existence. This is not hyperbole. A process that requires 50
to 100 times the operational cost is objectively terrible. In addition, the
same research implies a gross inadequacy for other uses like navigation,
search and operation.

The Zoom Grid I presented for analyzing the complexity of reading
illustrates three profound difficulties with zoomed web content. Assuming
we are using 400% enlargement of 16px font size on a 1280 by 720 page,
simple zoom creates the following problems.

1)  Operational complexity of reading goes up by a factor of 50 over normal
use or reading with screen reader. (Given a column width of 30% or greater)

2)  The buffer of characters that are immediately available for memory
support has no more than 36 characters. (That is one line) Note: For CJK
that is 18 for horizontal and 11 for vertical.

3)  General navigation, search and page operation goes up by a factor of 16.

The numbers for 1) have already been computed in [Operational Cost of
Horizontal Scrolling]. To see 2) note that a 1280px line really has about
90% useful space. Divide that by the average character width (near 8px) we
get 36. The third is also quite simple. If you zoom a page at 400%, you can
only view 1/16th of the content in any screen (4 across and 4 down).  That
means when a normal user must only search one page at a time, the user with
low vision must search 16 pages to survey the same information.

To proceed from this point on, AG must acknowledge that the original
assumption that screen magnification was accessibility support is a
falsehood. There is no use of simple zoom that does not create profound
difficulty. At best zoom is a bad accommodation for inaccessible content.

Again, I ask. What is the accessibility support for low vision? Enlargement
without word wrapping will never give equally effective access.