In many cases of trauma it is presence of cataract which denies the patient a good final visual result. Cataract may be caused by blunt or perforating injury. Intraocular foreign bodies may be held within the lens or pass through it. Lens opacities may also be caused by chemical burns and remote forces such as electrical current and radiational injury. Frequently the cataract is unilateral, causing considerable impairment of vision of one eye while the function of the other eye is normal and expected to remain so. The aim of surgery must be to remove all lens protein from the pupillary area and as far as possible from behind the iris.