Black spot on iPhone 4S front lens?

Everytime I take pictures with my front camera, a dark spot appears, even when I'm recording a video. It just appeared randomly one day and I know it's nothing to do with lens because it looks like its sort of built in? So it must be a hardware problem. I take good care of my phone, I've never dropped it, not a single scratch on it and I've had my phone for a little over a year? I have no insurance and my warranty has passed so i don't know what to do it kinda sucks that I have to be stuck with this phone for another year and I can't get it replaced. Anything I can do?

Go to apple.com
and see if it is a major problem
and look for a solution

Well defined? Dirt. Fibrous edges? Fungi. How to remove? Bring to Apple.