It is not known at present whether the post-operative complication of endophthalmitis can be prevented by perioperative use of antibiotics. This randomised study (masked and placebo-controlled for topical levofloxacin and unmasked for intracameral injection of cefuroxime) sets out to test in 4 groups, each of 8,750 cataract surgery patients, if either topical antibiotic (levofloxacin) perioperatively or an intraocular (intracameral) injection of antibiotic (cefuroxime) at the end of phacoemulsification cataract surgery or the combination provides effective prophylaxis of post-operative infection (endophthalmitis) compared to controls in whom perioperative antibiotics are not used. The result will provide a scientific basis for prophylaxis of infection (endophthalmitis) following cataract surgery in Europe as well as an accurate figure for the incidence of endophthalmitis following phacoemulsification cataract surgery in Europe for the first time.