Lever action intracapsular extraction of cataract is a new method; it derives its name from the fact that the lens in its capsule is dislocated and delivered by lever action. The scientific principle of lever action has been employed ever since the time of Archimedes, in 300 B. C., to perform work in which great resistance is offered or to raise a heavy weight with the expenditure of the minimum of power or effort.
In this procedure the lens is anchored by the attachment of its zonule. Some sort of power or effort must be applied so that the lens in its capsule may be dislocated by overcoming the resistance of the zonule. The nature of the power or effort applied in the different methods has been different. The power or force has to be applied directly to the lens or its capsule in some methods and from the