Why has my screen magnified? I can't get it back to normal.

I suspect this is a silly question and apologize in advance, but all of a sudden, all of the print and objects on my screen are magnified, and I can't figure out why, or turn it off. For example, when I type an email, I can only see about half of what I am typing, b/c the screen is enlarged enough that after five or six words, the text disappears off to the right. there is no scroll bar or other way to see what I am typing.

I hope I am describing this correctly. I've checked system preferences, the zoom feature (which remains off) and magnification (which also remains off) and i simply can't get this to go away. I've shut down and restarted - if anyone has any other ideas, I would greatly appreciate it. This is driving me crazy.