It is important that fonts can be made larger for all
Medical websites because most people who use theses have
imperfect vision .
a quote from
Jakob Nielsen's Alertbox
"Readability Guidelines for Websites
We can't wait for Microsoft to ship a good browser, though that has to
be the ultimate solution to the font size problem. For now, websites
can increase readability by following these guidelines:
Do not use absolute font sizes in your style sheets. Code font sizes in
relative terms, typically using percentages such as 120% for big text
and 90% for small text.
Make your default font size reasonably big (at least 10 point) so that
very few users have to resort to manual overrides.
If your site targets senior citizens, use bigger default font sizes (at
least 12 point).
If possible, avoid text that's embedded within a graphic, since style
sheets and font size buttons don't have any effect on graphics. If you
must use pictures of text, make sure the font size is especially large
(at least 12 point) and that you use high-contrast colors.
Consider adding a button that loads an alternate style sheet with
really big font sizes if most of your site's visitors are senior
citizens or low-vision users. Few users know how to find or use the
built-in font size feature in current browsers, and adding such a
button within your pages will help users easily increase text size.
However, because every extra feature takes away from the rest of the
page, I don't recommend such a button for mainstream websites.
Maximize the color contrast between the text and the background (and do
not use busy or watermarked background patterns). Despite the fact that
low-contrast text further reduces readability, the Web is plagued by
gray text these days"