Obviously, this strategy (which basically just degrades your monitor) isn't ideal. So, if you find yourself in a similar situation here are two things you should try first:
- If you're using either Internet Explorer or Microsoft Word, hold down Ctrl and roll the mouse wheel: this changes the size of the displayed font.
- If you're using something other than Internet Explorer or Microsoft Word, and no similar feature is available, then either try the operating system's magnifier (Start -> Control Panel -> Ease of Access -> Ease of Access Center -> Start Magnifier) or toggle the operating system's high-contrast mode (Alt-LShift-PrintScreen).
It's also worth noting that amazon.com just released a free piece of software called Kindle for PC, which lets you read any Kindle eBook on your PC at whatever font size you like: personally, I'm surprised at how little attention this new development has received in the technology press, given what a boon it is for the vision-impaired.