Rare-earth-doped　transparent　ferroelectrics　exhibit　outstanding　optical　transparency,　photoluminescence　(PL),　photochromic　(PC)　and　various　electrical　properties,　showing　potential　for　use　in　optoelectronic　applications.　However,　there　is　an　inevitable　trade-off　relationship　between　optical　and　electrical　coupling　during　the　integration　of　multifunctionality.　In　this　work,　Ba2+,　Ho3+　and　Yb3+　were　codoped　in　KNN　translucent-ferroelectric　ceramics　(as　a　model　material)　to　overcome　the　contradiction　between　optical　(transparency/PC)　and　electrical　properties　(resistivity/ferroelectricity).　The　defects　(mainly　oxygen　vacancies)　within　the　ceramics　can　be　effectively　regulated　through　annealing　under　different　atmospheres.　At　the　cost　of　a　slight　decrease　in　PC　performance,　the　electrical　properties　significantly　improved;　i.e.,　for　the　optimal　ceramic　annealed　in　an　oxygen　atmosphere,　both　the　maximum　and　remnant　polarizations　nearly　doubled,　and　the　resistivity　significantly　decreased　compared　to　that　of　the　original　sample.　A　mechanism　for　regulating　these　properties　was　proposed.　This　research　serves　as　a　valuable　example　for　adjusting　the　optical　and　electrical　properties　of　other　ferroelectrics　through　annealing.　©　2024　Elsevier　B.V.