sudden screen size changes on iphone 5s

My screen size on my iPhone 5s suddenly changes. There was a post that said tapping the screen did that and double tapping it would take it back. I tried double tapping and nothing happened. Is there a specific place we double tap.

I've been tapping on the bottom button and it makes it smaller, but it's still too big. I can't switch the screen from left to right.

What exactly are you talking about? Is everything zoomed in too much, even when no apps are open, or only in a certain app? Any chance you can post a photo of this?

I'm wondering if he turned zoom on from Settings, General, Accessibility? That will definitely make everything larger.

I was in the sprint store for something else and mentioned this and they told me to turn the zoom setting off, so I thing you are right chscag.
I don't know how to do a screen capture or shot?

Here's how the "zoom" setting works:

1. Double-tap with 3 fingers to zoom.
2. Drag 3 fingers to move around.
3. Double-tap with 3 fingers and drag to change the zoom level.

If you are able to do all this, then the "zoom" setting is on. Find that in the Settings app, under General, then Accessibility.

If this isn't doing anything, then something else is up.