The accompanying photographs illustrate the details of a retractor1 which was designed especially for use in the Krönlein operation to retract the orbital contents medially. Its proportions are based on measurements taken from plaster casts of a number of normal adult Fig. 1.—Retractor for the Krönlein operation. orbits. Its advantages over the usual narrow retractor are: (1) The blade is broad enough to protect the eyeball completely while the lateral wall of the orbit is being sawn through; (2) the shaft is so curved that it will not touch the bridge of the nose when the contents of the orbit are drawn toward the medial wall, and (3) the blade is so proportioned that the outer edges of the tip touch the floor and roof of the orbit, thus preventing the center of the tip from bruising or lacerating the optic nerve.