Hello A. Not much care needed with modern technology... Avoid head wash for 1 week.. Avoid lifting heavy weight... Avoid exposure to dust B. We  an operate the other eye after a gap of 1 week C. Decision regarding timing of surgery is taken By both patient and doctor... Baseline is  operate the patient as soon as patients feels difficulty in performing routine task D. Cost of surgery with foreign lens starts  from 15000 to 75000 approx. Depending on type of foreign lens You can read my health tip on cataract available on practo healthfeed