I have a pair of tortise acetate Persol eyeglass frames that I've had for a few years. They used to shine and be brilliant. I keep the lenses clean and polished but cannot seem to get the frames clean. There is a definite haze or film where my skin contacts the bows of the frame. It's dull and the frames are just lifeless. I've had this on previous glasses before and generally replaced the glasses. However, I'd like to keep these and maybe even swap lenses out and get another few years out of them. Maybe it's my skin chemistry or something? Has anyone encountered this? How did you clean and revitalize the frames?