Hold the CTRL key and scroll the mouse wheel, slowly.

The font increases are still very small and hard to read.    Why can we not adjust it larger than 13??  Please help!!

They get gigantically large on my screen (like too big to even be useful) when I hold the CTRL button and scroll the mouse wheel (go very slow with the wheel, it can be slow to react and suddenly things are way too small or way too big), 

key word on moving the mouse roller while doing this: slowly.. there is a lag on it responding and you can see the font size go next to nothing or gigantic in a second if you go too fast