Cataract surgery should be done within a month if there is a bilateral cataract and the fellow eye vision is more than 6/60. Cataract surgery should be done within a week if there is a bilateral cataract and the fellow eye vision is lesser than 6/60. Cataract surgery should be done immediately when affected eye vision is finger count is close to face and cataract has progressed significantly. Some patients with visual acuity of 6/18 or better may also have significant visual problems and they may also benefit from the cataract surgery. However, the risks of surgery compared to the potential for improvement of vision are higher in such patients. Before performing the cataract surgery, it is important to know whether the patient is unable to carry out routine work or the desired activities and how is this affecting his/her lifestyle.