Not damage but as mentioned, plating blisters/ bubbles from the copper wash that is applied to the zinc planchets. These were very prevalent in 1982/83 but lessened to some extent after that but were still common into the late 90s. After the change to the shield design, these issues abated mostly and now are the exception and not the rule. You just don't see them too much anymore. The mint seems to have kind if figured it out.