I have been there playing with other distros.
I may be speaking out of turn now, if so apologies, here goes.
There is a package in synaptic called orca
"GNOME screen reader for people with visual impairment
A flexible, scriptable, extensible screen reader for the GNOME platform
that provides access via speech synthesis, braille, and magnification."
If you are using KDE should be fine. I have not tried it
Also some quick key bindings:
Left Ctrl and scrollwheel may alter text and image size
In firefox Left Ctrl and + key does similar
Also I saw this excellent article in distrowatch which may be of interest:http://distrowatch.com/weekly.php?issue=20120521
Welcome to the funhouse