Cil. P. Ciliary process. S. Ch. Canal of Schlemm. L. P. Lig. pectinatum, between the fibres of which are the spaces of Fontana. Sup. C. Ly. S. Suprachoroidal lymph-space which extends backwards between the choroid and sclerotic. M. Longitudinal portion} of the ciliary muscle. C. M. Circular portion } O. Circulus arteriosus. S. Lig. Suspensory ligament of the lens. E. Epithelium covering the ciliary process. Pars Cil. Pars ciliariis retinæ. Pars plana of the ciliary body. R. The retina. } The junction of these with the pars plana is known as C. The choroid.} the ora serrata. J. Iris. S.M. Sphincter muscle. Cry. Crypt. M. M. Pigment epithelium. S. Cornea. Substantia propria. B. M. Bowman’s membrane. D. M. Descemet’s membrane. A. Cap. Anterior capsule of the lens. C. P. Canal of Petit. ] The lens is held in position by the suspensory ligament, which consists of interlacing fibres attached on the one hand to the ciliary process and on the other to the capsule at the lenticular margins (Fig. 84). Prolapse of the vitreous after cataract extraction is prevented by the integrity of this ligament and the posterior capsule of the lens, together with the hyaloid membrane of the vitreous. The tension on the fibres of the suspensory ligament, in addition to keeping the lens in its place, also exercises traction on the lens capsule. In dislocated lenses there is a gap in the suspensory ligament either as the result of injury or of congenital malformation; when such cases require operation there is some difficulty in producing a sufficient gap in the capsule to promote their absorption, owing to the mobility of the lens and the want of traction on the incision in the capsule. DISCISSION OR NEEDLING Discission of the lens has for its object the tearing open of the anterior capsule, so that the lens substance may be broken up and absorbed. =Indications.= This operation will be required: (i) =For cataract in patients under the age of about thirty.= The forms of cataract for which these operations are usually performed are: (i) _complete congenital cataract_, in which the whole lens is opaque and consists of little more than a shrunken capsule which may have to be extracted if discission is unsuccessful; (ii) _lamellar cataract_, of sufficient density to interfere seriously with vision; (iii) _posterior polar cataract_ in rare instances; (iv) _traumatic cataract_, to complete the absorption of the lens by breaking up its fibres. Before operating on any form of cataract the following facts must be ascertained as far as possible:--