Larger Font on F5 Screen

I can't read the numbers on my F5 screen. The lettering is too small. Does anyone know how to make the font larger? This goes for the Activity Editor too. I can't read train cars serial numbers and track labels, makes it almost impossible to create scenarios.
If anyone knows how to make these numbers larger, please reply. I'm about to go blind.
Thanks
Alex
If anyone knows how to make these numbers larger, please reply. I'm about to go blind.
Thanks
Alex