Eye nerve weakness. What we can do ?

Hi, Sir/ madam Sorry for the lengthy words, please read my problem. My father age is 63 years,he is a farmer .1 year back his right eye surgery is completed(layer forming ).After 1or 2 weeks he faced a problem of water in eyes, and he visited the hospital again aand again they give some drops, but it is not curable.   1 month ago we visited another hospital to treat that eye again, but that doctors recognized nerve weakness in both eyes, and they told me we can't do anything in right eye. But that doctors suggest Better do surgery for left eye,( layer forming)in that eye also 50-50  chances to come perfect vision because of nerve weakness.   So please suggest me can i go for left eye surgery ? I get confused, and my father is also scared because same right problem is repeated means what we can do  ? So please suggest me.