This could be caused by objects in the frame moving too fast. If this is the case, try taking a photo on demand while keeping objects still in the frame. If the photo comes out clear, then this is the issue. Keep in mind that in lower ambient light environments, the exposure level of the camera is higher, meaning that moving objects will be more blurry in lower light. If this is the case, try turning on lots of light and taking a photo on demand.
Ensure the lens is clean. Oils, dust, and other particles can build up on the Camera Lens. Try cleaning it off with a clean dry soft cloth.