If you don't have a center scroll wheel mouse, no problem! Just go to the top left Tool bar and Click VIEW..then, TEXT SIZE... you'll find about 5 or 6 sizes to Click and choose from, try them all to get whats best for you.

If your mouse has the center scroll wheel on it, hold down the Shift key (just above the Ctrl key) and you will go to previous pages, back and forward, but turn wheel slowly for this, too.

If you must choose between two evils, pick the one you've never tried before.