Smearing by wiper blades is usually down to some kind of contamination. It may be caused by some kind of localised air pollution, do you live near to a main road, airport or railway line which uses diesel locos? Or some kind of industrial facility? Try taking a piece of Kitchen roll or similar, soaked in neat screen wash fluid and clean your blades with it. Cleaning the screen in a similar manner will remove contaminants from it as well.
As Richard says, always ensure you use a good quality screenwash additive, diluted in accordance with the manufacturers recommendations. With particular attention to the instructions regarding cold weather use. Washing up liquid or plain water will NOT do!
I have had my C-Max since July, and although the blades appear to be in perfect condition, I too, suffer from smearing and poor overall performance. I do not know how old the blades fitted to the vehicle are, or their provenance. I am seriously considering changing them, which would be a shame as they are physically OK and I am very impressed with the wiper sweep pattern which covers a large part of the screen. They are OK for a couple of weeks after cleaning, then return to their smeary ways. I don't live in an area with air pollution problems, so I am wondering if they absorbed some contaminant from wherever the car lived previously.
I have always used good quality blades in the past and the ones I find best are Bosch. Some of the cheaper ones off Ebay, are truly rubbish. I once bought a set of "Retrofit Aero" blades for my Xantia, which looked excellent and performed well up to about 40 MPH. However, over that speed they lifted and twisted, becoming totally useless thereafter. I drove as far as the first garage, and replaced them with standard Bosch ones. Mark that down to experience!
2008 2.0 TDCi Zetec