FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
PLAYERS WHO NEED MAGNIFICATION
Many vision-impaired players simply need everything to be a bit larger. Older players provide a good example; after about age 45, most people need reading glasses—but even reading glasses aren't much help with tiny type. Tiny type is a bad idea in any case, especially if players have to read it under time pressure.
You can meet the needs of these people in three ways. First, if possible, allow players to change the font size of text that appears in your game, the way web browsers do. Second, support multiple monitor resolutions in your game. Let players who really need to see things in larger scale set their monitors to 640 x 480. If you have a complicated user interface, this may be rather tricky, but if it is, perhaps you should revisit the design of your interface and see if you can do without some of those screen elements. If you have a broad interface, consider making it deeper.
Finally, you can provide a magnifying glass feature that the player can move around over the screen to magnify different areas. The device probably won't be usable in action scenarios, but at least it's trivial to implement. Strange Adventures in Infinite Space includes a magnifying glass and switchable menu sizes, both of which are very helpful.
