Chemical　etching　experiments　are　carried　out　to　expose　and　change　the　morphology　of　multiple　scratches　and　single　scratches　in　a　set　of　K9　glasses,　during　which　the　transmission　of　some　glasses　is　measured.　The　results　show　that　brittle　scratches　have　an　influence　on　the　transmission,　and　the　transmission　decreases　at　first　and　then　increases　obviously　with　the　increase　of　etching　time　for　the　glass　with　a　high　density　of　cracks.　The　scattered　field　distribution　around　trailing　indent　crack(s)　and　the　transmission　of　the　glass　with　a　scratch　etched　deeply　(adjacent　cracks　have　coalesced　with　each　other)　are　simulated　under　different　parameters.　Using　finite-difference　time-domain　(FDTD)　algorithm,　the　light　intensification　effect　around　two　single-evolving　scratches　and　two　adjacent　cracks　with　different　parameters　are　simulated,　respectively.　The　results　indicate　that　the　position　with　the　maximum　light　intensity　changes　for　the　glass　with　a　scratch　and　its　light　intensity　enhancement　factors　(LIEFs)　will　generally　decrease　as　the　etching　process　progresses.　Compared　with　the　morphology　evolution　of　a　scratch　during　the　etching　process,　the　changing　mechanisms　of　transmission　and　LIEFs　are　revealed.　This　work　will　contribute　to　the　improvement　of　service　performance　of　optical　glass　by　chemical　etching　process.　(C)　2017　Society　of　Photo-Optical　Instrumentation　Engineers　(SPIE)