Cataract is the most important cause of visual impairment and decreased mobility in the elderly. While surgery is usually successful, it is also responsible for permanent loss of vision in up to 0.1% of patients due to severe post-operative infection (endophthalmitis). Because of this risk, surgery is typically performed on one eye at a time leaving the patient with a monocular cataract causing considerable visual impairment with reduction in mobility and quality of life. A second operation is required which often takes place up to one year later.