Shape factor in the penetration of intraocular foreign bodies.

We studied the way in which the shape of a missile striking the eye affects the ease of penetration of the central cornea. The test objects were enucleated pigs' eyes restored to normal intraocular pressure by cannulation of the optic nerve and connection of the cannula to a manometric system of physiologic saline. The shape, size, and weight of the missiles were carefully controlled. We attempted to keep these factors within the range of common civilian experience. Missile speed was measured photoelectrically. For each combination of weight and velocity, penetration of the missile was determined consistently, by the point shape. Penetration was most difficult for the blunt tip and least difficult for the knife-shaped tip.