font size is still too small on iMac desktop!

The turbotax font size for the desktop version on iMac is too small, and very difficult to read. I saw a post that showed a solution for the PC version to increase the font size, but the only solution provided for the mac was to use system preferences to change the resolution of the display. This is unacceptable! The font size is so small, that it is very, very, very difficult to read. Please provide a way to increase the font size on a Mac!