If you find the text on a website too small to read comfortably you can easily make it a bit bigger and this page explains how to do it in the following browsers:
Hold down the command key on your keyboard. On Macs the command key is indicated by an Apple or a cloverleaf symbol.
Press the '+' key to increase the font size or the '-' key to decrease the font size. Do this while still holding down the command key.
Stop when you've reached a font size that you can read easily.