Why are my iPhone pictures coming out blurry?

Lately all of my photos I take with my iPhone 4S have been extremely foggy or blurry. Any help on how to fix this?

Try cleaning the lense it might be smudged: p

Have you tried fogging it up with your breath and then wiping it with a cloth or shirt? I know it sounds stupid but it could just be a little dirty or have a fingerprint over it. Or if you have a case that covers the camera (lifeproof case) maybe the case itself is dirty. If that doesn't work I guess you could try restoring it if it becomes a huge problem, good luck!