I have seen a technique where the font is "enlarged" simply by outputting each scan of the character font twice. This makes the character appear taller. It can make the text surprisingly more legible with no more font RAM and just a small hit on the code space. Of course you still will need screen space. Because the characters, while more legible, are a bit ill formed, this might be available as an selectable "ZOOM" mode unneeded by those who purchase the reading glass option.
