Reduced visual acuity is probably the best-known aging problem, and yet websites with tiny type are legion. Sites that target seniors should use at least 12-point fonts as the default. And all sites, whether or not they specifically target seniors, should let users increase text size as desired—especially if the site’s default is a small font size.
Hypertext links are essential design components; using large text for them is especially important for two reasons: 1) to ensure readability, and 2) to make them more prominent targets for clicking. Also, you should avoid tightly clustered links; using white space to separate links decreases erroneous clicks and increases the speed at which users hit the correct link. This rule also applies to command buttons and other interaction objects, all of which should be reasonably large to facilitate easy clicking.
Pull-down menus, hierarchically walking menus, and other moving interface elements are problematic for seniors who are not always steady with the mouse. Better to use static user interface widgets and designs that don’t require pixel-perfect pointing.