If you hold down "Cntrl" and tap the + button the entire screen will enlarge. You can hit the plus for each enlargement. To reduce just reverse by holding down "Cntrl" and tapping the - button once for each reduction.

Helps me so much, thought I can't be the only one getting old out here....
Hugs!
Gayle

and, at least in Firefox, if you want to get back to the original size, you use CNTRL 0

Tried it on an Apple computer, and discovered it is the command and the + button. originall size is the same.

Thanks for that info!