Removal of a foreign body from the cornea requires a good light (focal illumination). The use of a binocular lens is also of service. Foreign bodies lodged on the surface of the cornea can be removed easily under cocaine with a spud. If the foreign body be deeply embedded in the cornea a fine sterile discission needle should be used. When a foreign body, such as a chip of iron, is deeply embedded, the needle should be inserted slightly to one side of the entrance wound and passed beneath the foreign body so as to lift it from its bed. When the foreign body has partially penetrated the anterior chamber but still lies in the cornea, an incision should be made with a keratome at the limbus and the foreign body pushed back through the entrance wound with the aid of an iris spatula. If the foreign body be iron, the electro-magnet may be of use, and in this case should be tried before resorting to an incision in the anterior chamber. A stain is left frequently after the removal of foreign bodies; this should be removed as far as possible. Subsequently the eye should be bandaged for a few days and bathed with boric lotion. Atropine should be instilled if there be any signs of infiltration around the wound. CAUTERIZATION OF THE CORNEA Either a chemical or the actual cautery may be used. =Indications.= _Corneal ulceration._ The cornea being extremely dense, organisms do not penetrate very deeply into its substance, so that destruction of the bacteria is effected by cauterization of the spreading portion of an ulcer; the albumin is also coagulated and so a barrier is presented to their advance. =Operation.= The eye is thoroughly cocainized, and the spreading portion of the ulcer is first defined by staining with fluorescine, washing away the excess of stain with boric lotion. _By a chemical caustic._ Liquefied carbolic (carbolic acid crystals liquefied in 10 per cent. of water) is applied upon a sharpened match. Any excess should be removed so as to prevent its running on to the cornea. A speculum is inserted and the cornea is dried by blotting with cigarette paper; the stained area is lightly touched with the point of the stick, particular attention being paid to the spreading margin. A dense white plaque is the result; this usually clears up in a few days. Atropine ointment is applied daily to the conjunctival sac. [Illustration: FIG. 127. ELECTRO-CAUTERY.] _By the actual cautery._ The electro-cautery (Fig. 127) point should be extremely fine and only raised to a dull red heat. The stained area should be touched lightly with the point. The actual cautery is best for serpiginous corneal ulcers, carbolic acid being more satisfactory for those of the vesicular type. OPERATIONS FOR CONICAL CORNEA