We've made a new skin available which increases the font size, making things easier to read for people who were complaining about the default Invision Board font size. This new skin is also set to the default. The old skin can still be used by those who prefer it, and you can change this by going to:
"Your Control Panel" up top -> Skin and Language (under options on the lower left), and selecting the skin you'd like from the pull down under 'Board Skin'.
We're working on providing more skins also, and hopefully a text only skin will be available before too long.