Right now the only way to see who viewed an item is by going in an encounter or opening a new encounter and then going into Review and then Change History. If you want to see who viewed an item in the Chart Summary and select Change History it only shows those items that were changed and not viewed. It would be more logical to see who viewed from the Chart Summary. Example if a provider needed to show to show legally when they viewed an attachment (as in a legal case) the only way to do that now is to open a new encounter.