As Zeus said, it may be worth checking your lenses out to see if they've gone foggy or yellowed. My Zed (on a 54 plate) had really foggy lenses so I rubbed them down with wet n dry, graduating to 2500grit and then coated the lenses with UV Protectant marine clear polyurethane. It made such a difference, I can see now. Or you could try polishing the lenses with Megs metal polish, that also works but again you'd have to apply something for UV protection.