Silver eye happens quite suddenly to older AGs from Pleasant Co. I haven't heard that it is a problem with the made in China dolls from AG. Based on earlier discussions (you can do a search on the Board for more information), it evidently occurs when the colored backing of the glass eye separates from the front of the eye, leaving just a silver colorless eye with the center pupil and the "whirligig" pattern around it. You can't prevent it. You can send a doll afflicted by it to the AG Doll hospital and they will replace the head of the doll at no cost except for shipping. The problem is that they sometimes replace the pre-Mattel made in Germany doll's head with the current made in China head, which alters the doll's appearance radically from my point of view. I have successfully insisted that only the doll's eyes be replaced but the new eyes are larger than the original ones. Gina (AGT19 with gray eyes) has silver eye in one eye and I masked it by buying her a gray-colored hard contact lens from a local optician. I glued the lens to her bad eye with clear fingernail polish. This is tricky and I wouldn't necessarily recommend it, but Gina shares my phobia about being sent to a hospital!