My grandmother is very old and weak. Recently she got some vision problem to which we took her to doctor and was found to be cataract on both eyes and the doctor told that she will go blind if surgery is not done immediately but there is a alot of doubts running inside my head... will the surgery be effective and how much Time will it take it heal as she is old and weak plus I think there is high chances of infection as her immune system is weak.. so, will be fine to do the surgery or not?? Obviously i want best for her but i'm confused