Out of the blue, my home screen background is extremely large the touch screen is not responding properly for me to slide the "slide to unlock button". I was able to get to it once and unlock but the radio buttons to enter my code were the same way: too large and I couldn't get to the correct buttons to unlock.
I'm sure the screen view needs to be reset, but cant access anything. I have restarted the phone numerous times, same result.
It sounds like the zoom setting might be on, you can check and turn it off under- settings-> general-> accessibility. If that's the case you should be able to zoom out with the 2 finger pinch option on the screen, double tapping, or scrolling with you finger on the screen to select the functions you need.