Dear Dr John Hang, thank you very much for your valuable advise. My father is 63, I would like to know is cataract progressive or may become stable with use of cataract eye drops ( I rally don't know are eye drops effective or may be harmful?.) or any other treatment except surgery? If it is progressive , in advanced stage is the surgery more difficult or not ? And how about the risk of glaucoma or any other conditions without surgery...Thanks a lot for your help