FaceTime camera has blurred lines during a FaceTime call but not during skype
Try a restart, hold the power button and home button together until you see the Apple logo appear, then release. It's perfectly safe and you won't lose any data, I restart my iDevices all the time.

It that doesn't work, report the bug to Apple and hope the public release of iOS 9.2 fixes your camera. You could update to the beta of iOS 9.2 if you're desperate for the camera to work, but the beta would also cause new, bigger problems.